Building Services Engineering Research & Technology

Dry bulb air temperatures are increasing especially in the UK. On top of this there is the urban heat island intensity (UHII), the temperature difference between rural and hotter urban temperatures. This is important as most new and existing buildings are in urban areas subject to the urban heat island (UHI)., In this paper is an analysis of weather data in Manchester city centre is compared to the CIBSE Design Summer Year type 3 (DSY 3) weather data. The latter, based on weather data from the Meteorological Office at a non-urban contains little if any UHII data. The DSY3 is based on a very warm year but the lack of the UHII data severely underestimates city centre night time temperatures and overestimates the winter minima temperatures. This underestimates the heating effect for net-zero design for urban buildings. A simple algorithm, which has been derived from Manchester and London data, is shown to give a useful method of adding in the UHII.

CIBSE weather files are currently used by the building industry as the standard input data for building performance assessment for the purpose of regulatory compliance in the UK. In this study, the state-of-the-art CIBSE weather files are created with four major improvements incorporated, namely, (1) the enhanced representation of the UK climate through the creation of discriminative climate zones; (2) the latest climate change signals from the UK Climate Projection 2018 (UKCP18); (3) the satellite based solar radiation data from CAMS (Copernicus Atmosphere Monitoring Service) data repository; (4) the up-to-date observation record from 1994 to 2023. The methodology for creating the latest CIBSE weather files is elaborated in detail to enhance the transparency of the new weather data. Evaluated using a simulation case study, the new weather files demonstrate spatial and temporal coherency. The new future weather files enable robust building performance assessment against future climate conditions under different scenarios and will play an important role in designing climate-resilient buildings and delivering a net zero built environment.

Energy Performance Certificates (EPCs) are indicators of building energy efficiency and carbon emissions across Europe, following the EU Energy Performance of Buildings Directive (EPBD). Assumptions behind EPC design differ significantly across Europe, despite emanating from a common starting point. Next Generation EPCs (NGEPC) relate to recently proposed updates to the EPBD, suggesting new functions and features that EPCs could adopt to be more useful for supporting decisions on zero carbon buildings. However, faced with such variation in approaches across Europe, this paper illustrates that a single pathway for upgrading EPCs will be difficult to achieve. Faced with this challenge, the paper presents methods of EPC categorisation to identify differences across European EPC approaches in a systematic way, directly addressing the consequences of a lack of harmonisation on the design of NGEPCs. By accounting for this variation, a framework is proposed for evolving specific EPC approaches to NGEPC status, captured in a way that is replicable to other EPC methods across Europe. Whilst the paper is informed by approaches across a selection of European countries, the situation in the UK is used as a more focussed case-study, with recommendations provided for how this approach may evolve in light of NGEPC progress.

This study investigates the potential of leveraging data from existing SBEM (Simplified Building Energy Model) energy certification models to generate dynamic simulation models for decarbonisation analysis. A case study of a healthcare centre in London was used to demonstrate the approach. The existing SBEM model was adapted into a dynamic performance model and tuned using measured energy data. The tuned model was then employed to simulate a range of refurbishment scenarios. Results indicate that achieving net-zero emissions will require a combination of building envelope upgrades, technical system improvements, and the installation of photovoltaic (PV) panels. To mitigate future overheating risks under projected climate scenarios, additional measures such as external shading or active cooling may also be necessary. To assess the scalability and accuracy of the method, the same approach was automated and applied to 164 additional NHS properties for stock-level assessments. At the stock level, simulated energy consumption closely matched measured averages across the portfolio. However, performance gaps in some individual buildings highlight the need for further investigation into SBEM model accuracy or refinement of model inputs to ensure reliable predictions when assessments are conducted at the building level.

The global issue of climate change is now readily accepted by most. Buildings contribute 40% of EU emissions, so the need to address mitigation is clear, but changing climate also creates a need for adaptation in buildings. Modelling is an accepted way of estimating the performance of buildings, but issues exist with accuracy and assumptions. This calls for measurements to be made on new build and retrofit homes. However, field measurements can have issues; they are time consuming, expensive, and can also be intrusive. It is for these reasons that the facilities “Salford Energy House” and “Energy House 2.0” were constructed at the University of Salford in the UK. These globally unique facilities allow for full scale homes to be built inside climatic chambers where variables such as temperature, wind, rain, solar radiation, and snow can be replicated, meaning weather conditions experienced by 95% of the worlds populated land mass can be simulated. The chambers are currently home to five structures in total; examining future housing systems, conservatories, window treatments and whole house retrofit scenarios. In this paper we will discuss the design, construction, benefits, limitations, and an overview of research findings from these facilities.

Retrofitting existing buildings is widely regarded as a key strategy for minimising the environmental impact associated with buildings throughout their life cycle. Although significant attention has been given to residential buildings and effective measures have been implemented, non-domestic buildings still require focused efforts to meet the UK’s sustainability targets. The healthcare sector is a major contributor to the existing non-domestic building stock due to its energy-intensive nature. In the UK, the National Health Service (NHS) operates a wide variety of hospital types, making it difficult to develop effective retrofit strategies that are suitable for all. Therefore, a strategic approach to retrofitting that is tailored to the specific needs and preferences of each NHS Trust is essential. This study examines a range of retrofitting measures for deep-plan and tower Hospitals (DPTH) and identifies the optimal design for reducing life cycle carbon emissions while accounting for stakeholder priorities. The results suggest that while certain optimal scenarios are effective in reducing operational energy use, further life cycle assessment (LCA) reveals different scenarios with a greater impact on lowering the building’s life cycle carbon emissions. Hence, additional life cycle carbon assessment is necessary to evaluate the full impacts of the optimal retrofit designs.