A comprehensive literature review and bibliometric analysis on shape grammar theory and applications in architecture

Abstract

Shape Grammar is a systematic tool used in the logical argumentive method in research for interpreting spatial design and activities. Shape grammar applies a group of shape rules in stages to create a set or a language of design. Researchers worldwide have used this method in various fields including architecture, arts, graphical design, and pattern recognition. Even in the case of architecture, researchers worldwide have implemented the shape grammar method to analyze patterns in various architectural fields. This study analyzed publication trends in the shape grammar domain using “Bibliometrix”, an open-source tool that uses the R package. Research papers from the Web of Science and Scopus (WoS) database were identified and assessed in terms of annual publication trends, contributions of various authors, countries, citation counts of authors, universities, popular keywords, journal trends, etc. A comprehensive literature review of all relevant research papers available in the WoS and Scopus academic databases on shape grammar and its application in architecture was also conducted as part of this study. The research paper concludes with the possible research opportunities in the domain of shape grammar.

Keywords

Shape grammar comprehensive literature review architectural design bibliometric analysis

Introduction

Shape grammar is a formalism that supports ambiguity in creative processes, translating visual and spatial thinking into design computation through shape rules and algebras.¹ The spatial relationships between the vocabulary elements are represented as rules. The methodology of shape grammar generation derived by George Stiny and James Gips revolves around the number of rules constituting a shape-generating system. This methodology, developed by George Stiny and Gips in 1970, has been applied to various fields of design, including art, automobile design, architecture, and product design. In architecture, shape grammar has applications in multiple specializations such as architectural design, urban design, traditional architecture, and housing. However, upon conducting a preliminary literature review, it became evident that there is a scarcity of literature review articles published in this domain.

T. Knight (1999) has authored a review paper on shape grammar in education and practice, outlining the roles of shape grammar in both practice and education.² Liu et al. (2018) reviewed grammatical formalisms supporting spatially enabled grammar. This study also considered the integration of shape and spatial graph grammar.³ In his research paper, Lionel March (2011) offers a concise explanation of the growth of shape grammars over 40years, spanning from 1971 to 2011. This paper refers to all publications, from Stiny’s initial work to Eloy and Duarte’s article on the shape grammar of Rabo-de-bacalhau apartments.⁴ Vitins and Axhausen (2016) reviewed shape grammar in the context of transport and urban design and analyzed the potential future developments and research prospects in this domain.⁵ Ahmed and Chase (2012) conducted a review focusing on style representation in design grammar to identify research opportunities related to planned style changes through grammatical transformations.⁶ Mandic and Tepavcevic (2015) analyzed the application of shape grammar in urban design and critically evaluated its implementation in various research papers. Their review of multiple databases revealed a lack of bibliometric analysis studies on shape grammar, thereby revealing the potential of conducting bibliometric analysis of shape grammar.⁷ Chai and Xiao (2012) conducted a bibliometric analysis of design research and acknowledged shape grammar as a valuable tool in design research.⁸ Bibliometric analysis is a method of evaluating scientific publications, such as articles or book chapters, using statistical analysis. This is an effective method to assess the impact of publications within the scientific community.⁹ It offers valuable insights into publication patterns, authorship trends, citation metrics, and collaboration networks, enabling researchers and stakeholders to gain a deeper understanding of the impact of particular journals. Also helps in identifying emerging trends and gaps in research, guiding future endeavors and fostering interdisciplinary collaborations. Eloy, Pauwels, and Economou (2018) demonstrated the practical and theoretical computer implications of shape grammar in their research, showcasing its diverse applications.¹⁰ Haakonsen, Rønnquist, and Labonnote (2022) highlighted the extensive work done with shape grammars in generating two-dimensional floor plans, emphasizing the increased digital development in recent years and the necessity for further research. Through a systematic literature review, their research paper mapped shape grammar applications in architecture and engineering over the last 50 years.¹¹

The articles^2–5,7,8,11 collectively demonstrate the absence of previous bibliometric studies and comprehensive literature reviews on shape grammar applications in architecture. Consequently, there is a research gap in conducting extensive literature reviews and bibliometric analyses on shape grammar. This in-depth review contributes significantly to the understanding of shape grammar and its diverse applications.

This paper presents a thorough literature review of the topic of shape grammar theory and its applications in architecture. The review encompasses relevant research papers gathered from reputable databases such as the Web of Science and Scopus. Additionally, this study undertakes a comprehensive analysis of the publication scope and conducts descriptive assessments based on search results from the Web of Science and Scopus databases. This paper not only identifies suitable journals for publication but also highlights pertinent keywords and research areas within different subdomains of shape grammar. By examining a wide range of sources, this study aims to provide a comprehensive understanding of the subject and contribute valuable insights into the fields of architecture and shape grammar theory.

Methodology

This paper presents a thorough literature review of the topic of shape grammar theory and its applications in architecture. The review encompasses relevant research papers gathered from reputed databases, such as the Web of Science (WoS) and Scopus. Additionally, this study undertakes a comprehensive and bibliometric analysis of the publication scope and conducts descriptive assessments based on search results from the WoS and Scopus databases. Bibliometric analysis is a popular and rigorous method for exploring and analyzing large volumes of scientific data.⁹ In addition, bibliometric analysis has limitations in terms of the databases used and keywords selected for the search.¹² The choice of database can affect the accuracy and completeness of the search results, as different databases may have different coverage and indexing methods. By examining a wide range of sources, this study aims to provide a comprehensive understanding of the subject and contribute valuable insights into the fields of architecture and shape grammar theory.

The study methodology was influenced by the research of Nadkarni and Puthuvayi¹³ and Lazar and Chithra.^14,15 The research conducted by Nadkarni and Puthuvayi provides a comprehensive and in-depth review of relevant articles from the Web of Science academic database on the application of MCDM(Multi Criteria Decision Making) methods in heritage buildings. This review includes a bibliometric analysis to examine the current state of the art and to understand the publication trend and trajectory in this field using a final list of 42 articles.¹³ Lazar and Chithra conducted a comprehensive literature review of 78 articles on building sustainability assessment systems from WoS and Scopus.¹⁴ They conducted a bibliometric analysis of building sustainability assessment systems using 52 articles from the Scopus database using Bibliometrix, an R tool.¹⁵

Figure 1 illustrates the methodology used in this study. The primary objectives of the literature review were formulated first, and search keywords and search strings were finalised based on the objectives. The primary objective of this research is to explore the applications of shape grammar in various fields of architecture and understand publishing trends in recent years. The following keywords were expected to be present in the title, based on the study objectives:

1. Shape Grammar

2. Architecture

3. Application/design/tool

Figure 1.

Methodology of research.

The search string was formed as follows

TS= (shape AND grammar*) AND (tool OR application OR design*) AND architecture *

Searches in both WoS and Scopus databases were performed using the search terms mentioned above in June 2024. The topic search included the title, abstract, author keywords, and Keywords Plus. The language of the articles was restricted to the English language. The search results in WoS and Scopus are summarised in Table 1.

Table 1.

Search results in scopus and WoS.

Process	Description	Search results in scopus	Search results in WoS
Search in WoS and sscopus database	Initial results	n = 194	n = 123
Initial screening	Filtration of research papers in the English language and journal publications	n = 84 (1 research paper in Chinese omitted and 109 other categories omitted)	n = 76 (2 research papers in other languages and 45 other categories omitted)
Detailed screening	Screening based on boundary conditions	n = 58 (26 research papers omitted)	n = 53 (23 research papers omitted)
Adding the missing articles	Searching the references of articles	n = 94 (36 research papers added)	n = 70 (17 research papers added)
Common articles	Research papers common in both the databases	58 research papers common

Arriving at final list off 94 from Scopus.

The search period included articles from the entire search span of both databases. The initial results yielded 85 research articles from Web of Science and 72 articles from Scopus. During the screening process, two non-English papers were removed from the Scopus list. Subsequently, 23 articles from the Web of Science list were eliminated as they did not meet the boundary conditions set by the search string. The excluded articles were either unrelated to shape grammar, or focused on shape grammar applications outside the field of architecture. To complete the list, additional articles that fulfilled the search criteria were added by reviewing the references of the initial search list. Eight research papers were appended to the Web of Science list and one research paper was added to the Scopus list. After refinement, the final WoS list comprised 70 research papers. As 58 articles were common to both databases, the final list comprised 94 articles from Scopus. As the WoS database contains only articles from 2000 to 2024, we observed a difference of 24 articles between the two databases. Thus, we arrived at a final list of 94 articles from the Scopus database from 1991 to 2024. To facilitate the analysis, the final list of 70 articles was exported in BibTeX format and processed using the bibliometric tool provided by the R-studio package. The bibliometric tool, the Bibliometrix R-package, enables quantitative research in bibliometrics and scientometrics, and is written in the R language, an open-source environment and ecosystem.¹⁶ The most-cited research articles and productive authors were analyzed using the Bibliometrix package in R.¹⁴

Shape grammar, a generative tool developed by George Stiny and James Gips in the 1970s, marked the beginning of the domain’s publication span thereafter. The Scopus database only contains articles published from 1991 onwards, however, in the comprehensive literature section, we have included early publications from 1970 to ensure that all key publications in the domain are included (Arriving at a final list of 108 articles). We have systematically classified the final 108 articles into nine distinct categories based on the specific applications of shape grammar within the field of architecture: (1) shape grammar theory, (2) shape grammar applications in housing, (3) shape grammar applications in architectural design, (4) shape grammar applications in traditional architecture, (5) shape grammar applications in architectural history, (6) shape grammar applications in urban design, (7) shape grammar applications in pedagogy, (8) shape grammar in analyzing designs of master architects, (9) and shape grammar applications in landscape architecture.

Results

Descriptive analysis

Annual publication trends

The annual publication trend provides insight into the publication trends and growth of the domain over time. Figure 2 depicts a consistent positive linear growth trend in the publication from to 1990-2024. A notable increase in the number of publications was observed between 2011 and 2020. Although there may have been a slight dip in subsequent years, the overall publication trend exhibited a positive linear pattern, indicating a continued growth in the field.

Figure 2.

Annual Publication trend.

Authors and affiliations

A total of 161 authors contributed to 94 relevant articles, 20 of which were single-authored, with an average citation per document of 18.9. Table 2 lists the authors with the highest numbers of publications and citations during the search period. Jose Pinto Duarte is the author with the maximum number of publications. He authored six articles between 2005 and 2024 and received a total citation of 173. Eloy S was the second most productive author, with five publications published within 13 years. Lee JH and T Knight are the other productive authors who published four articles. Stiny, one of the pioneers of shape grammar, had only two publications in this period, but the total citations show that he was one of the most contributing authors in the domain. The most contributing author affiliations were from MIT, Carnegie University, and the Technical University of Lisbon.

Table 2.

Authors with the most number of publications and citations.

Authors	Articles	Total citations	Publication year start
Duarte JP	6	173	2005
Eloy s	5	37	2011
Lee JH	4	29	2013
Knight T	4	119	1999
Gu N	3	25	2017
Havemann S	3	77	2010
Ostwald MJ	3	25	2017
Al-azhari WW	2	11	2020
Boned J	2	66	2013
Krishnamurti R	2	50	1995
Krispel N	2	63	2010
Stiny G	2	164	1991

Most cited articles

The number of global citations represents the total number of citations received by a document from all publications indexed in a source, whereas the number of local citations refers to the number of citations a document received from other documents in the specific search. The most globally cited article in this domain is Duarte’s research article on the mass customization of Siza’s designs in Malaguira,¹⁷ and this paper has been cited 115 times. The second most cited article was Tapia’s article on the visual implementation of shape grammar systems.¹⁸ The third most cited article is Shape Grammar, which describes shapes using Cartesian systems.¹⁹ Figure 3 shows the globally most-cited papers, whereas Figure 4 shows the most locally cited articles. Among the articles cited locally, the article by Cagdas on Turkish house grammar ²⁰ is the most frequently cited, and the article on the shape grammar interpreter for rectilinear forms also has more local citations.²¹

Figure 3.

Most global cited articles.

Figure 4.

Most locally cited articles.

Figure 5 shows the co-citation network of the selected documents. Three early publications of G. Stiny on shape grammar theory in the years 1972, 1978 and 1980 are the most co-cited articles. This demonstrates the contribution of G Stiny to the shape grammar domain.

Figure 5.

Co-citation network.

Most relevant journal

The 94 research papers reviewed in this study have been published in 43 journals. Among these journals, ‘Environment and Planning B-Planning and Design’ has the highest number of publications in this domain, followed by ‘Nexus Network Journal’ in the second position. Other relevant journals include ‘AIEDAM, ’ Computers and Graphics, and the International Journal of Architectural Computing’. The most pertinent journals in the discipline are presented in Figure 6, and Figure 7 illustrates the growth of these journals over time. The data visualized in the figures indicate a positive trend of growth for both the ‘Nexus Network Journal’ and ‘Environment and Planning B: Planning and Design’ in terms of the number of publications. ‘Environment and Planning B: Planning and Design’ exhibits a progressive increase from 1993 to 2006, while ‘Nexus Network Journal’ displays a consistent linear growth that has persisted to the present day.

Figure 6.

Most relevant journal.

Figure 7.

Source’s production over time.

Most occurring keywords

The most frequently occurring author keywords and keyword plus were identified based on their occurrence in the journals. Author keywords that accurately reflected the content of their documents were selected by the authors. However, keyword plus consists of words or phrases that frequently appear in the titles of references cited within an article, rather than in the article’s title or as author keywords. The most frequently identified keywords and their occurrences in articles were extracted from 94 research papers and are listed in Table 3.

Table 3.

Most occurring keywords.

Author’s keywords		Keyword’s plus
Words	Occurrences	Words	Occurrences
Shape grammars	22	Shape grammars	30
Architectural design	10	Design	3
Architecture	9	Design theory	3
Design	9	Islamic architecture	3
Computer aided design	6	Urban design	3
Geometry	6	Aesthetics	2
Procedural modeling	6	Algebra	2
Housing	4	Design education	2
Spatial analysis	4	Design tool	2
Three dimensional computer graphics	4	Generative design	2
Vernacular architecture	4	Generative systems	2
Architectural style	3	Graph grammar	2
Computation theory	3	Housing	2
Computational design	3	Making grammars	2
Computer graphics	3	Mass customisation	2
Generative design	3	Reflective practice	2
Product design	3	Space syntax	2
Semantics	3	3d	1
Shape grammar	3	Additive manufacturing	1

The word “Shape grammars” is the most common keyword in keyword plus and the author’s keywords. “Design”, “Design Theory”, and “Islamic Architecture “are the other most occurring words in keyword plus. “Shape grammar,” Architectural design”, “architecture” and” design” are the most occurring authors’ keywords. From Figure 8, we can see that the keywords “shape grammars”, “architecture design”, and” design have shown consistent growth since 2000.

Figure 8.

Word’s frequency over time.

Author’s keywords and journals

A three-field plot was created using Biblioshiny with R studio (Figure 9) featuring the author’s keywords (DE) on the left, the author’s name (AU) at the center, and the source (SO) on the right side. Each field was limited to 14, including the 14 most productive authors. This plot provides insights into authors’ research and journal publication domains. It is evident from the three-field plot that Duarte and Eloy were the most productive authors with articles under six keywords, followed by Al-Azhari. The journals titled “Nexus Network Journal” and “Environment and Planning B: Planning Design” (Present Environment and Planning B: Urban Analytics and City Science) have publications spanning various keywords, followed by “Computers and Graphics” for the selected authors. Table 4 shows the authors’ keywords used in the journals” Environment and Planning B: Planning Design” and “Nexus Netwok Journal,” as these journals encompass a more comprehensive range of keywords than the others in the dataset. This information provides a deeper understanding of the research focus and diversity of topics covered by these journals.

Figure 9.

Three plot diagram in Biblioshiny:DE (keywords),AU(Authors),SO(Source).

Table 4.

Author’s keywords in journals.

Journal name	Keywords	References
Nexus network journal	Algorithms; computational design; design education; geometry; parametric design; shape grammars	⁴³
	Ancient egyptian architecture; late period private tombs; rock-cut funerary monuments; shape grammar	²²
	Algebra; design theory; materials; shape grammars	²³
	Algebra; design analysis; domotics; housing rehabilitation; information and communication and automation technologies (icat); measuring systems;	²⁴
	De re aedificatoria; design automation; leon battista alberti; rapid prototyping; shape grammars; theory of architecture	²⁵
	Attunement; choreography; corporeal architecture; performance; shape grammars	²⁶
	Design; design theory; shape grammars; style	²⁷
	Portuguese urban design; proportion; shape grammar; symmetry	²⁸
Environment and planning B: Planning design	Design analysis; design generation; glenn murcutt; normalised distance; shape grammars	²⁹
	Architectural style; built environment; contextual design approach; generative design; shape grammar; spatial analysis; traditional architecture	³⁰
	Design methods; justified plan graph grammar; shape grammars; space syntax; spatial analysis	³¹
	Adapted design; design method; residential space; shape grammars; vernacular housing	³²
	Bosangwhamun; content analysis; culture; hierarchical deconstruction; shape grammar	³³
	Architectural design; building; graphical method; mapping	³⁴
	Construction; design; three-dimensional modeling	³⁵
	Computer system; construction industry; design; housing; eastern hemisphere; eurasia; europe; evora [Portugal]; malagueira; Portugal; souther	¹⁷
	Architectural style; cultural influence; design approach; housing design; shape grammar; traditional housing; vernacular architecture; taiwan	³⁶
	Architectural design; historical style; shape grammar; Turkey; anatolia; Turkey; rumelia	²⁰
	Architectural design; housing; vernacular architecture; Bosnia and Herzegovina; eastern hemisphere; eurasia; europe; sarajevo; southern europe	³⁷
	Architectural design; design; spatial analysis	³⁸

Bibliometric review -dicussion

The initial publication of shape grammar dates to 1972. Examining annual publication trends, we can observe slow growth in publications from 1985 to 1995. However, there was a notable increase in the number of publications between 1995 and 1998. During the 1980-1990 period, early publications mainly focused on shape grammar theory and its potential as a computational tool. Subsequently, the second phase, concentrating on the application of shape grammar, emerged. From 2000 to 2012, there was another surge in publications, with 2020 having the highest number of publications. Authors such as Knight, Krishnamurti, and Stiny have significantly contributed to the introduction of shape grammar as a tool in design research. Initial researchers used this tool to analyze the architectural styles of various master architects. However, over time, shape grammar has found applications in various architectural sectors, including interior design, landscape architecture,³⁹ urban design,⁴⁰ and settlement studies. From 2005 to the present, we can see that shape grammar has been used in building form generation, facade design generation, etc. This evolution indicates that shape grammar has evolved into a potent computational tool since 2000 with diverse possibilities in all fields of architecture. One possible reason for this trend may be the development of computational research from 2000 onwards. During this period, various universities began to use shape grammar as a pedagogical tool for teaching architectural design.^2,41,42 As a result, more publications on applying the tool in pedagogy have been published since the year 2000. Overall, the publication trends in shape grammar exhibit steady positive linear growth from the earliest to the present day. Ongoing research on computer-aided architecture is likely to significantly contribute to this continuous development. The Nexus Network Journal has more publications on shape grammar, as it deals with visualization, computation, and formal design-based methods applicable to morphological processes and structures in cities and regions. Following closely is the Journal Environment and Planning B: Planning and Design ranks second, with the highest number of shape grammar publications. The prominence of this journal in this domain can be attributed to its early contributions to the publishing of relevant research papers.

Stiny, the author of the pioneering article on shape grammar, made significant contributions by authoring four papers published between 1972 and 2008. Stiny’s work primarily revolves around the shape grammar theory and its fundamental applications. Table 2 presents the most productive authors: Duarte JP, Eloy S, Lee, and Knight T. Among these, Duarte JP contributed six publications from 2005-12 to. Duarte (2005) developed a shape grammar for creating mass housing by generating the grammar of Siza’s houses in the Malaguiera. Duarte’s mass housing grammar is the most cited paper (115 citations). The second most cited research article is by Tapia (1999), in which he visually interprets shape grammar (108 citations).¹⁸ Thus, the most cited papers focus on the application of shape grammar in design.

Carnegie Mellon University and the Massachusetts Institute of Technology of the United States have emerged as the most productive affiliations, likely because of significant research contributions to shape grammar from the Massachusetts Institute of Technology. Portugal and France are countries that have generated a significant number of publications. Countries such as Malaysia and India have recently entered the scene with their initial publications, indicating that developing countries are in the early stages of research in computer-aided design.

Keyword analysis sheds light on the scope of further research on design tools, theory, and computational grammar. The positive growth trends observed for the keywords ‘shape grammar’ and ‘design tool’ suggest promising opportunities for future research in this domain. The bibliometric analysis results affirmed the relevance and potential of the publication of shape grammars in architecture.

Comprehensive literature review on shape grammar and its applications in architecture

14 articles from the 1970-1990 period is added to the mainlist of 94 articles and arrived at a final list of 108 articles. The 108 research papers were systematically categorized into nine distinct categories, based on the type of shape grammar application and shape grammar theory. The categories were selected based on a preliminary literature review and analysis. The identified categories are, 1. Shape grammar theory 2. Applications of shape grammar in housing 3. Applications of shape grammar in architectural design 4. Applications of shape grammar in traditional architecture 5. Applications of shape grammar in architectural history 6. Applications of shape grammar in urban design 7. Applications of shape grammar in pedagogy 8. Shape grammar for analyzing the design of master architects 9. Applications of shape grammar in landscape architecture. Table 5 presents the different categories, the corresponding numbers of research papers, and their summaries. An analysis of the table reveals that a significant portion of publications pertain to the theory and conceptual aspects of shape grammar. This includes articles discussing shape grammar, shape grammar interpreters, shape boundaries, shape rules, and sub-shape detection algorithms. The higher number of articles in this category indicates the research scope and continuous growth of shape grammar theory. The categories ‘Applications of shape grammar in architectural design’ and ‘Applications of shape grammar in traditional architecture’ follow with a substantial number of publications. The former comprises articles related to facade parsing, grammar formulation of patterns, colours, materials, and interior layout generation. On the other hand, ‘Applications of shape grammar in traditional architecture’ focus on the shape grammar generation of various traditional and vernacular architectural prototypes. In contrast, the domains ‘Applications of shape grammar in landscape architecture’ and ‘Applications of shape grammar in pedagogy had the least number of articles. Figure 10 illustrates the evolution of each domain over time, with the period between 2011 and 2020 showing the highest number of publications across all the domains. Notably, both ‘shape grammar theory’ and the application of shape grammar in traditional architecture have exhibited consistent growth from 1970 to 2020. Figure 10 shows the development of these domains over time.

Table 5.

Article categories.

	Category	No of papers	Subcategories
1	Shape grammar theory	25	Basic concepts-20^{1,18,19,23,25,38,43–45,78,100,103–105,107–113,127–130} Parametric shape grammars-4-^46–50 Review paper-1⁴, New forms of grammars-2-^51,52
2	Shape grammar applications in housing	8	Mass customization-5 ^17,53–56 Vernacular house types-1,³⁶ Vertical housing-2^24,57
3	Shape grammar applications in architectural design	16	Façade design-5-,^58–63 Materials-4-^64–67 Colour applications-1 -⁶⁸ Art and architecture-3^43,69,70 Interior layout generation-1,^31,71 Concept design-4 ^72–74 Typo-morphological classification-1: ⁷⁵ Procedural modelling-3 ^60,76,77
4	Shape grammar applications in traditional architecture	11	Traditional residential designs-10,^{20,30,36,37,78–80,115,117,123} traditional educational building-1-⁸¹, Traditional market-1- ^82,83
5	Shape grammar applications in architectural history	4	Digital heritage-2^84,85 Typology defining tool-2 ^22,86
6	Shape grammar applications in urban design	8	Sustainable cities-1-,⁸⁷ Urban modelling-3-^40,88,89 Urban shape grammar-2-^90,91 Urban development model-2-^28,92,93
7	Shape grammar applications in pedagogy	2	Pedagogical tool-3-^2,41,42
8	Shape grammar in analyzing the designs of master architects	7	^{17,25,29,35,94–97}
9	Shape grammar application in landscape architecture	3	Landscape planning-1-³⁹ Historical gardens:2-^95,98

Figure 10.

Evolution of categories.

Shape grammar theory

Twenty-four of the 108 selected research papers focused on the shape grammar theory. The first publication in the domain was in 1972 by George Stiny and James Gips which introduced shape grammar as a generative specification for painting and sculpture.⁴³ After 3 years James Gips authored an elaborate book on shape grammars and their uses.⁹⁹ The same year, George Stiny came up with a more pictorial version of shapes and shape grammars¹⁰⁰. In 1978, Stiny and Gips published Algorithmic Aesthetics: Computer Models for Criticism and Design in the Arts.⁴⁴ An article with shape grammar formalism and the definitions and ideas on which it is based was published in 1980.¹⁰¹ The article discussed basic terminologies and formalisms of shape grammar. Kindergarten grammar is a constructive approach by Stiny for defining the language of designs using Frederick Froebel’s kindergarten method.¹⁰² T Knight formulated a procedure for defining new languages of designs from known or given set of designs in his article in 1981. Krishnamurti presented an algorithm for shape rule applications in the same year using all the notations introduced by Stiny (Krishnamurti, 1981). T Knight published another article about usage of shape rules and shape equivalence rules for decoding historic styles.¹⁰³ As a continuation to the above article, T Knight published three articles on the translation of design languages.^104,105 In this set of article,The first one characterized relationships between historic styles of designs or to construct new and original styles from known ones.¹⁰⁴ In the second article, Formal model describes transformations of design languages through grammars.¹⁰⁴ The third article generated a model for design transformations using architectural styles by Frank Lloyd Wright.¹⁰⁵ In 1987, Stiny published an article about rules and their role in compositions.¹²⁹ T Knight expands formalism for stylistic change in design through comparisons and transformations.¹⁰⁶ The paper “Shapes and shape grammars: from mathematical model to computer implementation” presented several key findings and results about shape grammars and their computer implementations Stiny defines ‘design’ differently with shape grammar and shape algebras in his next article¹⁰⁷.

The most prominent and influential contributing author in this domain is Stiny, recognized him as the pioneer of ‘shape grammars’. The most cited article in the domain is by Stiny (1991) describes shapes as the main computing device of shape grammar algebra. This article explains the representation of shapes as Cartesian products in shape grammar algebra. These articles discusses different approaches to shape representation in shape grammar.¹⁹ Another article by Stiny in 1996 points out the types of useless rules using shapes and shape identities in grammar formulation.¹⁰⁸ Fleisher in his article, ‘Shape grammars in architecture: rules, forms, and design exploration’ explores the basic design explorations using shape grammar in architecture. Tapia explains Visual shape grammar system implementation in 2D with points and lines¹⁸.

An Article by Earl in 1996 described a shape using the algebra of the subshapes and the process of its generation. He defined shapes using shape boundaries and elements such as points, lines, and planes. The article also described the types of shape boundaries, including element boundaries, closure boundaries, and specially defined boundary shapes, using in-shape algebra. This study focused on the distinctions between the subshape and point descriptions of shape boundaries.¹⁰⁹ T Knight categorizes shape grammar into six types:1. basic grammars, 2, non-deterministic basic grammars, 3. sequential grammars, 4. additive grammars, 5. deterministic grammars, 6. Unrestricted grammars.³⁸

Similarly, Krstic authored a paper with similarities but introduced a specific shape algebra tailored for concurrent computations involving shapes and shape boundaries in relation to shape grammar. In this study, shape boundaries are defined in three ways: (1) A shape boundary is the set of boundaries of its elements. (2) A shape boundary is a group of boundaries with the utmost elements. (3) The shape boundary is the sum of the boundaries of the utmost elements. Furthermore, the author introduces a new type of grammar called “collision protecting grammars,” which aims to prevent collisions between the two sides of a rule.¹¹⁰

Shape grammar generation involves computations that address the ambiguity in shapes or other indefinite parts. T Knight’s paper in 2003 explores the ambiguities in shape grammar generation. The author delves into representational ambiguity, which pertains to uncertainties in the representation of the shape elements. In this paper, T Knight (2003) introduces formal strategies for computing with the emergence and ambiguity of particular kinds.¹¹¹

Shape grammar interpreters are vital for computer implementation of shape grammar. Yue, Krishnamurti and Grobler (2009) develop computer-friendly parametric shape grammar interpreters, detailing a sub-framework over parametric two-dimensional rectangular shapes. This study also explored the relationship between shape and graph grammar.⁴⁸ Hoisl and Shea (2011) presented a new approach and sample implementation for a three-dimensional grammar interpreter that allowed interactive visual development and grammar rules. The author explained the process using three samples: kindergarten grammar, cylinder cooling fins, and vehicle wheel rims.⁴⁹ Grasl and Economou (2018) introduced a parametric shape grammar interpreter based on a graph grammar. Subshapes are identified using subgraph detection to derive parametric grammars.⁴⁶ As a continuation of this article, Grasl and Economou’s (2013) other paper implements subgraph detection for parametric shape grammars.⁴⁷ Jowers and Earl (2011) generated an algorithm for parametric curves and their shape operations to help generate shape grammars for curves. These algorithms were applied using a shape grammar interpreter for shape compositions using Bezier-curves. This study highlights the scope of shape grammar applications in solving patterns using curves and other design disciplines, with curves as the predominant element.⁵¹

Shape grammar-based design systems are used to automate design processes while incorporating various design options. A meticulously crafted grammar facilitates the generation of design projects within predefined user-defined constraints. Chase (2002) discussed a user interaction system tailored to grammar-based design systems. In this work, the author presents a formal model that enables the seamless integration of grammar systems driven by user interactions with CAD tools.⁵²

Al Kazzaz and Bridges (2012) employed computing techniques, including hybridization, transformation, and substitution, to adapt shape grammar theory for architectural practice.¹¹² Yue and Krishnamurti introduces a paradigm for interpreting tractable shape grammars.⁵⁰ In their work, T Knight and Stiny (2015) present a computational theory that modifies algebras to accommodate shapes’ materials and defines algebras for objects’ materials. The authors described shape grammar as a shape computation process aimed at creating various objects (Knight & Stiny, 2015b). Gursoy and Ozkar (2015) contributed to research involving a materially informed approach with shape rules, demonstrating how the careful application of rules can help explore the physical properties of materials.¹¹³ In a different context, March (2011) provided a historical account of the development of shape grammar from 1971 to 2011. This paper elaborates on the progression from Stiny’s first article in 1971 to three papers published in Nexus Journal in 2011.⁴ One of the latest articles by Celik analyzed shape grammar as a generative tool for designing experiments in the concept stage.⁷⁴

Shape grammar applications in housing

This category comprises six research papers that focus on shape grammar applications in housing. These six articles were published between 1995 and 2023. The major research within this category revolves around mass-customized housing. Duarte and Correia (2006) developed a description grammar aimed at customizing mass housing based on site and user data. This description grammar facilitates the generation of online housing programs that adhere to Portuguese building regulations. This study can be seen as a follow-up to Malagueira grammar. The computer implementation of Malaguiera grammar, MALAG, along with its two modules, PROGRAMA and DESIGNA, was a part of their research.⁵⁷ A research paper authored by Knight and Sass (2010) also focuses on mass-customized housing. Their study explored the development of cost-effective and high-quality building assembly systems for mass customization using shape grammars and digital fabrication. By utilising shape grammar, this study provides aesthetically rich design options for mass housing and other small-scale buildings.¹¹⁴ Eloy and Duarte (2011) presented another application of shape grammar in housing.²⁴ Their article discussed the formulation of a grammar that aims to rehabilitate housing using information, communication, and automation technologies. This study explores the technological requirements of inhabitants and different forms of grammar in architecture. In 2017, Eloy developed a grammar for Rabo-de-bacalhau apartments, in which the design quality of shape grammar-generated designs was compared with designs created by architects. This study emphasizes the potential of shape grammar as an independent design system in architecture.⁵⁴ In another research, Lo, Aydin, and Schnabel (2014) devised a mass-housing design using quasi-grammars. They collaborated in shape grammar, game theory, BIM, collaborative design, and BIM to create a model for mass housing projects in Kashgar. The method employed here is referred to as the ‘Gamification of shape grammars,’ representing an alternative approach to mass housing.⁵⁵

Al-Jokhadar and Jabi (2020) propose a mechanism for combining the spatial and formal features that affect public life in vernacular houses in the Middle East and Africa. They formulated a socio-spatial parametric grammar specifically tailored for contemporary vertical residential buildings in the same region, adhering to sustainability principles. To facilitate the implementation of social sustainability strategies from the early stages of design, researchers have developed a computer tool based on constructed grammar. This tool empowers architects and designers to effectively incorporate social sustainability considerations into their designs.⁵³ Belcic and Eloy implemented shape grammar as a tool for transforming single-family houses into old housing in Slovenia.⁵⁶

Shape grammar applications in architectural design

In architecture, shape grammar is useful in both design analysis and generation. Among the 108 articles reviewed, 14 specifically pertained to shape grammar applications in architectural design. The foundational work on shape grammar can be traced back to Stiny and Gips, who introduced the concept of generative narration of painting and sculpture in their initial research contribution. In this seminal article, the authors propose that design problems can be effectively addressed by specifying an art object, rather than focusing solely on the object itself. This groundbreaking work marks the inception of shape grammar applications in architectural design.⁴³

Among the 14 articles in this category, many focused on facade generation using shape grammar. Haegler and colleagues introduced a new grammar named “f (acade)shade, specifically designed for encoding facades. F-shade grammar is used on a base polygon, which is parameterised according to the texture coordinates. The researchers evaluated the Munich city model using this grammar to demonstrate its effectiveness and applicability.⁶¹ Muller et al generates algorithms to automatically derive 3D models of high visual quality from single-facade images of arbitrary resolution.⁶³

Similarly, Riemenschneider et al. (2012) generated a facade using the shape grammar of irregular lattices. They introduced a method to treat symmetry and repetition in generic grammar. The generated algorithm supported hierarchical spatial relationships, symmetries, and repetitions. The authors experimented with various architectural styles of different complexities.⁵⁹ In 2013, Murphy and Dore (2013) created a semi-automatic method for modelling facades using shape grammars with Historic Building Information Modelling (HBIM). They implemented a new method for creating heritage models in a digital form using photogrammetry or laser scanning using HBIM, a plugin used in BIM. The method used here combines procedural modelling techniques and parametric modelling with shape grammars. They created a facade using a parametric shape grammar that follows the rules regarding the position of elements and proportioning systems.⁶² Eilouti (2019) used shape grammar as a tool for parsing in reverse engineering to generate the morphogenesis of visual compositions in architectural designs. The façade configuration is explained using 13 rules and rules defining all panel treatment possibilities in designated façades. The reverse engineering application of shape grammar was presented in article.⁵⁸

The shape grammar has always been implemented in the design process, considering its generative aspects. Trescak Rodriguez and Esteva (2009) established a shape grammar interpreter for generating intelligent designs which follow functionality and aesthetics. The authors introduced a generic shape grammar interpreter (SGI) to automatically generate the designs. The authors also developed a tool to detect sub-shapes during the generation process.⁷³ Jowers et al. (2009) used shape grammar for shape detection in conceptual design. The application of this system considers shape exploration in conceptual design. The system automates the detection of shape subshapes and enables the execution of shape rules in shape grammar. Design alternatives are generated by modifying concepts using design rules.⁷² Yue, Krishnamurti and Grobler (2012) developed a shape grammar interpreter to estimate the interior layout of buildings to capture building style. The authors formulated an algorithm using shape grammar to determine the interior layout and to generate buildings with rectangular spaces. The algorithm is formed using three factors: the footprint of each storey, complete set of exterior features, and shape grammar stating the building style. The shape grammar of the Queen Anne houses was generated for the same sample study.⁷¹

Shape grammar was implemented to analyse patterns and compositions in architectural designs. Huang et al. (2005) use shape grammar to explore the underlying geometrical pattern of Zillij mosaics and Kuba cloths. Serra (2013) uses shape grammar to analyse the possibilities and strategies of colour in architectural composition. The research emphasises grammar rules and the syntax of colour.⁶⁸ MacLachlan and Jowers (2014) modelled multimaterial surfaces as weighted shapes and used them in shape computation. This paper discusses the addition of materials to computational design. Multi-material surfaces are demonstrated as weights in shape computation, and they formalise the description and manipulation of graphical representations using shape grammars.⁶⁵ This study used shape grammar as a tool for cultural preservation. Kamath (2020) generated the grammar of a thin tile vault as an example of grammar generation for materials and tectonic complexity.⁶⁴ Ashrafi and Meisal created a grammar-based algorithm to identify the material deformation in concrete generation.⁶⁷ Ali and Mustafa use shape grammar as a tool for the typo-morphological classification of mosques. The study was carried out using pattern recognition with the graph technique.⁷⁵ Santos et al. proposed ShapeGraMM (Shape Grammar for massive models), an expandable grammar that procedurally generates geometries in real time to create 3D scenes of massive models.⁷⁶

Shape grammar applications in traditional architecture

In 1977, Stiny generated parametric shape grammar of traditional Chinese ice-ray lattice designs, which can be considered as one of the earliest applications of shape grammar in traditional architecture.⁷⁸ Ice-ray lattices were ornamental window patterns constructed between 1000 and 1900 AD. T Knight had generated shape grammar of Japanese tea houses using 41 rules considering the traditional feng-shui principles.⁷⁹ In 1994, T Herbert and Sanders formulated the grammar of African Ndebele homesteads. The grammar generation process involved considering the omission of missing information regarding homesteads, and the authors concluded their research by proposing possibilities for generating murals in Ndebele homesteads. The primary aim of the study was to define the architectural style of linear Ndebele homesteads while taking into account traditional rules and social customs of the tribes during the grammar generation process.⁸⁰ In 1995, the grammar of traditional Taiwanese houses was developed by Chiou and Krishnamurti, considering Chinese architectural principles. The grammar generation was based on viewing Taiwanese Houses’ bilateral symmetry and Feng Shui principles of Chinese architecture.³⁶ The role of grammar generation in defining design style is explained using the four dwelling types of Taiwanese Houses in the following article by the same authors¹¹⁵ Cagdas (1996) generated the parametric grammar of traditional Turkish houses in 1996. He placed spaces above an imaginary grid, and spatial relations were represented in a matrix. The rule schema was generated based on syntactic analysis of the plans. The generation process was based on the choice and placement of the centre hall.²⁰

In the same year, Cagdas formulated the grammar of English rowhouses by employing rules developed through formal, syntactic, functional, and dimensional knowledge.¹¹⁶ In 2005, Colakoglu developed an informal shape grammar for Hayat-style houses of Ottoman architecture, employing a three-stage process to generate new designs in the same style. The first stage focused on generating the primitive Hayat house design, the second stage involved the generation of sub-houses, and the third stage produced variations in house design.³⁷ Buthayna H. Eilouti contributed two articles that delved into the applications of shape grammar in traditional architecture. The first research, along with Al-Jokhadar (2007), focused on generating plan layouts for educational buildings in the context of Mamluk architecture. The grammar generation process involved a step-by-step derivation, employing a total of 93 rules.⁸¹ In the second study, Eilouti and Hamamieh (2012) formulated a grammar for traditional Damascene courtyard houses. They achieved this by creating rules based on numerical parameters derived from the mathematical analyses of Damascene dwellings. Abdulqader and Ibrahim (2017) generated the grammar of wooden embellishments in the Baba-Nyonya shophouses, a mix of Chinese and Malay architecture. Visual analysis was used to identify the algorithm for generating wooden embellishments, which are the most significant elements of shop houses.⁸³ Yousefeniapasha et al. (2019) investigated 44 houses in four villages to derive the vernacular housing typologies facing the rice field and derived four vernacular typologies. The grammar generation was conducted considering climatic and cultural factors.¹¹⁷ Lambe and Dongre (2019) analyzed the scope of shape grammar in contextual-based conservation using an example of Pol houses in Ahmedabad. They generated the grammar of pol houses using a rule schema based on the hierarchy of spaces.³⁰

Shape grammar applications in architectural history

Aydin and Schnabel (2014) are pioneering the revitalization of history through the integration of shape grammar and virtual reality to recreate Kashgar, an ancient city. Their study leveraged shape grammar and gamification techniques to virtually reconstruct Kashgar, infusing historical significance into the virtual environment. The research methodology is based on a combination of shape grammar and gamification, as outlined in their work.⁸⁴ Similarly, Wutte and Duarte embarked on the generation of parametric shape grammar for Egyptian monuments, aiming to define the typologies present within these historical structures.²² Battini et. Generated historical architectural vaults using digital heritage and incorporated shape grammar.⁸⁵

Shape grammar applications in urban design

Brown and Johnson’s publication in shape grammar application in urban design dates back to 1985. They developed a shape grammar model of the morphology of medieval London systems. Duarte was the author with the highest contribution to the domain. Duarte, Rocha, and Soares (2007) derived the parametric shape grammar of Medina of Marrakech in Morocco. The grammar generation considered urban fabric and housing grammar. The model comprises three grammars: a grammar that generates houses, a grammar to trade spaces among adjacent spaces, and an urban fabric grammar.⁹⁰ Jan, Antje, and Schmitt (2008) apply shape grammar to master planning. This study derives high-quality complex city models using procedural modelling in shape grammar. Duarte et al. (2012) developed an urban design machine to create flexible urban plans at the site planning level. This model consists of three sub-models. The first is a model for urban development programs based on Christopher Alexander’s pattern language. The second sub-model is a model for generating urban plans based on Stiny’s shape and description grammar. The third sub-model evaluates urban plans.⁸⁸ Duarte, Beirao, and Stouffs (2011) formulated urban grammar to produce customised urban designs. In another article, the authors described the generation of urban patterns using shape grammar. This study explains the urban modules and common urban practices.⁴⁰ In a case study of Lunaga in Angola, Paio et al. (2011) developed a system that unveils the social, cultural, and spatial factors related to the birth of informal settlements with a case study of Lunaga in Angola.⁸⁷ Noronha et al. (2022) used shape grammar as a tool for city retrofitting.⁸⁹ Al-Fadalat and Al-Azhari created a shape grammar model for Amman City using shape grammar procedural modelling.⁹¹ Therefore, shape grammar serves as a dual-purpose tool and is used as both a generative and analytical tool in urban design.

Shape grammars applications in analyzing the designs of master architects

Shape grammar was used as a tool to analyse patterns in the works of the master architects. Buelinckx generated a parametric shape grammar that characterised the plan designs of Wren’s City churches.⁹⁷ Duarte (2005) generated the grammar of patio houses designed by Alvaro Siza in Malagueira for mass customisation of housing. The generated grammar can be used to create customised Malagueira houses. This study proposes a computer program that encrypts grammar to generate Siza’s designs more efficiently.¹⁷ Louis Sullivan’s designs consist of a system of ornamentation. Phillips (2008) decoded this ornamentation system by using informal shape grammar. Shape grammar is used to analyse Louis Sullivan’s designs and to generate new designs following the design language. The grammar generation consists of seven groups of rules for defining the ornamental compositions of Louis Sullivan.⁹⁴ Sass (2007) translated the design process of Palladio’s villas by using shape grammar. Palladian grammar is generated from 11 rules based on an analysis of Palladio’s villas.³⁵ Lee and Ostwald generate the shape grammar of Murcatt’s domestic architecture and illustrate the possibilities in the translation.²⁹

Shape grammars applications in landscape architecture

The selected articles revealed a limited number of publications that focused on shape grammar applications in landscape architecture. Stiny and Mitchell generated parametric architecture of Mughul gardens in 1980 considering the geometry and paradise concept.⁹⁵ T Knight formulates color grammar that describes the composition and landscaping of Mughul gardens following stiny’s and Mitchell’s work⁹⁸ Mayall and Hall (2005) conducted research on generating landscape grammar to define the character of landscapes using the vocabulary of landscape object types and grammar rules. This spatial grammar is instrumental in generating digital landscapes in both two-dimensional and three-dimensional formats. The authors successfully implemented the grammar structure and production system in a residential neighbourhood located in Bermuda.³⁹

Shape grammar applications in the architectural pedagogy

In his review, T Knight (1999) examines the role of shape grammar by analyzing its previous applications in both educational and practical contexts.² Meanwhile, Ibrahim et al. (2012) utilised shape grammar to establish a methodology for first-year design studios, demonstrating that students experience increased productivity through grammatical exploration.⁴¹ Mahdy’s article explores the significance of shape grammar as a coding tool in architectural curricula.⁴³

Discussion

The earliest publication on ‘shape grammars’ dates back to 1972, followed by a significant increase in publications from 2012 to 2022. Stiny’s initial publication on shape grammar was presenting it as a generic specification to describe paintings and sculptures. The first architectural application was published in 1977, which is ice-ray grammar followed by Palladian grammar. But later on, numerous researchers explored various possibilities for its applications, leading to a continued trend of interest in the subject. Stiny, Gips and T Knight contributed towards shape grammar theory during 1970-1985. The 1980s witnessed some of the key works of authors Flemming and Stiny such as Queen Anne Houses,¹¹⁸ Buffalo bungalow grammar¹¹⁹ and Mughal Garden Grammar.⁹⁵ The first three-dimensional grammar was established in 1981 by Koning and Eizenberg¹²⁰ Subsequently, from 1990 to 2000, the majority of research efforts concentrated on the application of shape grammar in traditional architecture. Over the next 10 years, shape grammar has been employed to analyse the styles of master architects. The period 2010 to 2022 proved to be the most influential phase for shape grammar, witnessing its application in various architectural contexts and new contributions to the theory itself. This growth could be attributed to the advancement of computer-aided design during this time and the development of technologies, such as parametric modelling and parametric architecture, which likely facilitated and fuelled interest in shape grammar. During this phase, there was a noticeable increase in research papers exploring shape grammar interpreters and collaborative efforts with parametricism and gamification, which opened new avenues for research and practical applications.

Shape grammar gained popularity as a generative and analytical tool during the 1980s. The use of shape grammar in Palladian Villas and grammar generations of traditional typologies, such as Taiwanese houses, showed the potential of shape grammar in analyzing architecture as well as in generative architecture. Generative possibilities have been utilised in mass customisation of urban design and housing since the 2000s. By 2010, shape grammar began to be used in procedural modelling, and more advanced versions of grammar generation began. More shape interpreters were also generated as part of the growth of the domain.

Similarly, in the domain ‘shape grammar applications in architectural design, major articles were on façade generation. Articles on facade generation were published in the 2010-2019 period. The domain consists of various applications in architectural design, including conceptual design and colour compositions. Numerous publications emerged throughout this period, contributing to the advancement of the field.

The literature review established the significance of shape grammar as a valuable tool for generating, evaluating, and analyzing existing designs (Table 6). Most studies have employed shape grammar as a tool for generating designs, considering it as a generative design algorithm. The formulation or automation of the design process constitutes a substantial aspect of computational design research. The use of shape grammar aims to assist designers in exploring and optimising the generated designs.¹²¹ A well-designed grammar should produce designs and possibilities consisted.¹²² First computer implementation of grammar was by Lionel March. Shape grammar has been established as a computational theory for architecture.

Table 6.

Type of applications and sources.

As a generative tool	16	^{1,24,39,53,57,64,81,83,90,93,113,114,123}
As a reverse engineering	2	^58,60
Image visualisation tool	6	^{55,61,62,66,84,113}
As a tool for contextualism	5	^{37,80,114,117,124}
As evaluation tool	7	^{33,35,59,71,88,92,94}
As a design tool	10	^{40,46,52,54,68,69,72,73,125,126}
As a computational/design theory	13	^{4,19,23,46,48,51,108–112,127}
As a pedagogical tool	2	^2,41,43
As a recording tool	1	⁷⁰

Shape grammar serves not only as a design tool but also as an analytical tool. It finds applications in both traditional architecture and analysis of designs by master architects, exemplifying its analytical capabilities. In the past, shape grammar generation was a manual process, but with the advancement of computer tools, grammar has become more digitised, leading to the development of shape grammar interpreters. This shift to digital media contributed to an increase in the number of publications between 2000 and 2020. During this period, most shape grammar theory articles focused on shape grammar interpreters and 3D visualisations. These advancements have enabled shape grammar to exhibit generative, analytical, and evaluative powers, thereby expanding its scope in pedagogy. However, it is evident that there have been significantly fewer studies exploring the applications of shape grammar in pedagogy.

The Descriptive analysis reveals that Environment and Planning B: Planning and Design is the most pertinent journal for publication in the shape grammar domain, which holds significance, as some of Stiny and Knight’s key articles elucidating shape grammar theory were published in it. Another noteworthy journal is the Nexus Network Journal, primarily due to its notable increase in the number of publications after 2015.

The most commonly utilized terms by authors and keywords plus are ‘Shape grammars,’ ‘design,’ and ‘architectural design.’ The frequency with which these keywords appeared indicated the prevailing publication trend in the domain. Another noteworthy observation was that many of the keywords were repetitive or interconnected. These keywords often signify various application types of shape grammars, such as ‘design tool’ and ‘generative tool.’ However, the specific area of application for shape grammars has received relatively little mention as keywords. Surprisingly, despite numerous articles focusing on ‘Shape grammar application in traditional architecture’, the term ‘traditional architecture’ was not prominent among the keywords. This suggests that in the case of these articles, the type of application holds greater significance than the specific domain of traditional architecture.

Figure 11 shows the contributions of the most productive authors in each category. As search results are from the period 1991-2024, Duarte is the most influential author in the period and contributed to all architectural sectors, excluding landscape. Descriptive analysis results show that Duarte has more total citations than Stiny, March and Gips. It may be due to later advancements in the domain. Eloy applied shape grammar to three aspects of architecture. G. Stiny and T. Knight are the authors who contributed the most to shape grammar concepts. The most cited articles are ‘shape grammar applications in architectural design’. The most locally cited article deals with the shape grammar generation of traditional Turkish houses.²⁰ But We can also see that most co-cited articles are written by Stiny one of the pioneers of shape grammar. So most co-cited articles are early publications on shape grammar theory.

Figure 11.

Productive authors and contributions.

One noteworthy aspect of the shape grammar literature, as identified in this review, is the diversity of approaches, ranging from highly theoretical to those with strong practical applications in industrial and software implementations. Stiny emphasises shape grammar as a theoretical tool for analysis.¹⁹ On the other hand, utilising shape grammar in facade generation and design demonstrates its potential as a practical and generative tool in real-world applications.

Conclusion

Shape grammars have been utilised for analysis and generation purposes across diverse fields, such as architecture and industrial design. Given the significance of this research domain, this study undertook a comprehensive literature review using a bibliometric approach. The analysis involved 94 articles retrieved from the Scopus database up to 2024. Descriptive analysis was performed to uncover various insights, including yearly publication trends, most cited articles, most contributing authors, top countries of contribution, frequent journals, and commonly used keywords. Notably, the sudden surge in publications starting in 2020 indicates promising research opportunities and growing interest in the field of shape grammar.

The results indicated that shape grammar initially gained popularity as an analytical tool from 1970 to 1990. Subsequently, it became renowned as a generative tool, particularly in architectural design, from the 1990s. By the early 2000s, shape grammar had gained prominence in facade generation. The widespread adoption of shape grammar as a generative tool has resulted in an increase in publications that focus on architectural design and traditional architecture. The combination of analytical and generative capabilities of shape grammar has led to further research on revitalising traditional architectural styles and integrating traditional rulesets into contemporary architecture. In 2020, shape grammar was utilised as a typology-defining tool in architectural history. Simultaneously, it found applications as a pedagogical tool in architectural design studios. Moreover, since 2000, shape grammar has been widely used as a mass customisation tool in the urban design sector. Given the analytical, generative, and evaluative potential of shape grammar, it is anticipated that its adoption will continue to expand into various architectural sectors in the future. Presently, shape grammar studies predominantly originate from developed countries, such as the US and the UK, with institutions such as MIT and Carnegie University being prominent contributors. Hence, there is a need for countries like India to participate actively in research publications related to shape grammar. Such research endeavours can foster the growth of computer-aided design research in these countries. Shape grammar is a promising research tool for evaluating, analyzing, and generating architectural designs. Its growth signifies its research potential and ability to decode various aspects of architecture, encompassing both architectural practice and architectural education.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Linas Fathima A

Chithra K

Data availability statement

The data that support the findings of this study are not available for any resources.*

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