Environment and Planning B: Urban Analytics and City Science

Sustainable housing has been a major topic of national policy in the Netherlands for fifteen years. The author argues that sustainable housing is a badly defined concept, both in scientific literature and in policy documents. The Dutch government has never indicated how the sustainability of housing could be measured, or realized a zero measurement, which would enable researchers to evaluate environmental policies to promote sustainable housing properly. A narrow definition of sustainability is adopted, whereby the author concentrates on the ecological dimensions of the concept of ‘sustainability’: the environmental impact on the greenhouse effect; the quality of air, water, and soil; noise nuisance; stench; the stock of nonrenewable materials; and biodiversity. An overview of ways in which the sustainability of housing can be measured is given and the use of a multivariate yardstick advocated. A set of recommendations is presented for politicians and public officials about the way in which sustainable housing can be promoted, and a research agenda on sustainability in housing presented. The author concludes by pointing out the analogy between the Dutch government's policy to promote sustainable housing and the story of the emperor's new clothes. The moral is that it is better to acknowledge that we do not know essential things about sustainable housing than simply to ‘believe’ in it.

In 2003 the European Commission introduced the EC Directive on the energy performance of buildings in recognition of the importance of energy savings in the urban housing stock. The Directive gives the member states freedom to design the different elements in practice. The energy certificate for existing buildings demanded by the EC Directive can be used as a communicative instrument, or combined with economic or regulatory principles. The authors discuss the anticipated efficiency and effectiveness of different policy approaches in the application of the EC energy certificate for the urban housing stock. They argue that, although energy certificates as a communication instrument for household appliances have appeared to be relatively successful, the different nature of the building sector may mean that their effectiveness here will be rather limited. The combination of energy certificates with tax schemes seems promising, but will have to be coupled with general income taxes or in housing-related taxes in order to prevent regressive social effects. Combination of the energy certificate with subsidies should be limited, because of the ‘free-rider effect’, and subsidies should only cover innovative products at the beginning of their ‘learning curve’. Effective results can probably be expected from the introduction of regulations combined with energy-certificate standards, but this requires a rather drastic approach and needs time to receive sufficient commitment, as has been the case for new buildings where there has been a gradual development of energy regulations over the last thirty years. However, an introduction of energy standards for the existing urban housing stock through the EC energy certificate offers great potential in the realisation of CO₂ reductions. The introduction of an energy standard, by means of the energy certificate in combination with progressive taxes or other economic measures to reward better and punish worse energy-performance levels, seems an interesting approach that needs further research.

Assumptions about the effects of various land-use characteristics on travel patterns have found their way into diverse concepts of planning and design, such as the compact city and neighbourhood-design principles. In general, these concepts aim at reducing travel distances and reducing car-travel speed, as it is assumed that as travel distances are shorter, individuals will travel less, and the relative competitive position of slower modes is increased. Although some literature supports the link between land use and travel behaviour, for the greater part limited effects have been concluded, whereas in others it has been concluded that there is virtually no effect. We argue that the effects fall short of the expectations advocated by the land-use concepts, because of shortcomings behind assumptions concerning the relationships between land use and travel behaviour. We argue that utility-based and activity-based theories add some extra insights. Various behavioural responses in terms of travel-time changes are possible, depending on whether travel time is minimised, benefits maximised, or activity patterns optimised. It is concluded that the contribution of compact urban designs to reduction on travel may not be as straightforward as is suggested by their advocates. In any case, a simplified distance-oriented and trip-oriented approach is unable to examine complex behaviour, and a broader framework of space and time is needed.

Governance to support sustainable development always seems to encounter the same difficulties. The chances of successful governance increase when governance arrangements are better tuned to the environment that it tries to change. However, a better fit leaves less room for change. Governance arrangements supporting sustainable development are more prone to failure, as they aim at changing that environment. Radical institutional change is at the core of sustainable development, but without the help of external factors, such as major crises like the oil crisis in the 1970s, the sense of urgency for such radical change is lacking, and incremental change seems to be the only road available. The authors explore how governance arrangements deal with this recurring barrier to institutional change. Their conclusion is that the more governance arrangements respect the institutional context in which they are used, the higher their quality. To speed up the incremental track, the design of governance arrangements should include positive incentives for actors to cooperate.

Scenario-based investigations of possible futures have been used since the middle of the 20th century to help decisionmakers cope with alternative courses of action and elements of uncertainty. Since the early 1970s, they have been increasingly used for landscape planning. Each scenario-based study is founded on assumptions of possible change. Often these beliefs are only implicit among scenario creators and scenario users. I discuss the beliefs and perceptions about the future of scenario creators and scenario users, and argue that they should be explicitly addressed before an investigation is undertaken in order to avoid methodological biases in the creation of the scenarios and misunderstanding of the results. As part of this discussion, the basic features of a scenario-based study are reviewed, and applications to landscape and environmental planning are considered, with examples drawn from two studies that were focused on the same concerns and in the same region but which employed different kinds of scenarios.

The aim of exploring and monitoring housing-market fundamentals (prices, dwelling features, area density, residents, and so on) on a macrolocational level relates to both public and private sector policymaking. Housing market segmentation (that is, the emergence of housing submarkets), a concept with increasing relevance, is defined as the differentiation of housing in terms of the income and preferences of the residents and in terms of administrative circumstances. In order to capture such segmentation empirically, the author applies a fairly new and emerging technique known as the ‘self-organising’ map (SOM), or ‘Kohonen map’. The SOM is a type of (artificial) neural network—a nonlinear and flexible (that is, nonparametric or semiparametric) regression and ‘machine learning’ technique. By utilising the ability of the SOM to visualise patterns, one can analyse various dimensions within the variation of the dataset. Segmentation may then be detected depending on the resulting patterns across the map layers, each of which represents the data variation for one input variable. Utilising an inductive modelling strategy, the author runs cross-sectional and nationwide data on the owner-occupied housing markets of Finland (documentation presented elsewhere), the Netherlands, and Hungary with the SOM technique. On the basis of the resulting configurations certain regularities (similarities and differences) across the three national contexts are identified. In all three cases the segments are determined by physical and institutional differences between the housing bundles and localities. The exercise demonstrates how the inductive SOM-based approach is well-suited for illustrating the contextual factors that determine housing market structure.

The author adopts reduced-form equilibrium models to investigate the relations among vacancy, employment, space consumption, and rent in the Hong Kong office market under economic structural change. The models are estimated with the aid of data from Hong Kong during the period 1980–2002—a total of twenty-three yearly observations. It is hoped that empirical results will shed light on the adjustment mechanism of the local office market. In line with the existing literature, the author shows that, on the one hand, office rent is positively related to office employment, but inversely related to office stock. On the other hand, the demand for office space is inversely related to rent, but positively related to office employment. Moreover, the elasticity of space consumption with respect to rent is estimated to be inelastic. Historical simulations of the model are performed, and it is suggested that the equations simulate reasonably well as indicated by Theil's inequality.

Data-poor environments, or where data are not routinely collected and/or poorly archived, or where public records are not easily accessible understandably create a major obstacle to research and the reaping of the benefits of research for urban policy and urban management. However, in such rather unwelcoming research environments GIS seems to provide enhanced opportunities for maximizing the benefits of whatever data are available, as scarce as they may be. This research condition may not be unique to the case study presented here but presumably may apply to most countries in the developing world. The authors' use of GIS for the analysis of the case of an old neighborhood of Amman outlines a procedure for zooming in on areas of construction activity and understanding the relation between physical and social change, social change being here represented by change in landownership.

This paper explores the application of an informal shape grammar whose purpose is to generate new house designs in the hayat style. The hayat is a large shaded gallery open to the garden. It occupies the most important place in the composition of the house. The study is based on a corpus of eight hayat houses designed in the classic Ottoman style in the 18th and 19th centuries in Sarajevo. In this paper, the emphasis is on the generation of new houses. The informal grammar does not explain the designs in detail but rather generates new house designs by transferring some knowledge embedded in original designs. The generation of a new house type within the grammar proceeds in three steps: (1) primitive hayat house generation, (2) subhouse generation, and (3) house variations.