Sustainable construction: the development and evaluation of an environmental profiling system for construction products

There has been a rapid increase in the number of low environmental impact or ‘green’ buildings constructed in recent years, due to factors such as the UK government's Sustainable Development Strategy, new environmental legislation and perceived operational and business advantages. Consequently, the demand for up‐to‐date information, guidance and design ‘tools’ to help property professionals procure greener buildings also continues to grow. The development of a new edition of one such tool: The Green Guide to Specification, was based on research designed to evaluate user needs and current design and specification practices and expectations. Many property professionals do not use environmental tools on all projects because of time considerations and the disruption caused by having to take an ‘extra step’ in the design and specification process. Specifiers would only use such tools either when instructed to do so by clients or because of the specifier's own organisational green agenda. For environmental tools to be more widely used, information should also be embedded within commonly used specification programmes such as the National Building Specification (NBS) as well as in stand‐alone versions.     

The life cycle impact of refurbishment packages on residential buildings with different initial thermal conditions

Existing buildings constitute a large portion of the UK’s housing stock. Refurbishment of existing buildings can, therefore, have an important role in achieving the UK government’s CO₂ reduction targets. While building regulations and rating frameworks mainly focus on the improvements of the operational performance of buildings, Life Cycle Analysis is considered to be a more appropriate framework to account for long–term CO₂ savings. This study evaluates a range of retrofit approaches (simple, medium, and deep), in terms of Life Cycle Carbon Footprint applied on a terraced house—one of the most common housing archetypes in London. The initial state of the original building has also been examined assuming three initial states (never refurbished, refurbished in compliance with the 1976 and with the 2000 building regulations). Results showed that for all initial state scenarios, deep retrofit achieved the lowest life cycle carbon emissions, in absolute figures, compared to the simple and medium retrofits. Simple retrofit packages, on the other hand, achieved quick and significant improvements, especially in buildings with poor initial thermal conditions. The study also indicated that retrofit packages applied on highly efficient building fabrics result in longer carbon payback time periods. The study recommends establishing a ‘staggered’ retrofitting approach, which pushes for ‘older building first’ and ‘simple retrofit packages first’, as these gain quick CO₂ savings. Deep retrofit packages and treatment of relatively new buildings should be implemented at a later stage, to push buildings further to Zero–Carbon target.

     

Development of an adaptive window-opening algorithm to predict the thermal comfort,energy use and overheating in buildings

This investigation of the window-opening data from extensive field surveys in UK office buildings demonstrates: (1) how people control the indoor environment by opening windows; (2) the cooling potential of opening windows; and (3) the use of an ‘adaptive algorithm’ for predicting window-opening behaviour for thermal simulation in ESP-r. It was found that when the window was open the mean indoor and outdoor temperatures were higher than when closed, but it was shown that nonetheless there was a useful cooling effect from opening a window. The adaptive algorithm for window-opening behaviour was then used in thermal simulation studies for some typical office designs. The thermal simulation results were in general agreement with the findings of the field surveys. The adaptive algorithm is shown to provide insights not available using non adaptive simulation methods and can assist in achieving more comfortable, lower energy buildings while avoiding overheating.     

Sonnenschutz: Eine generelle Bewertungsmethode – auch für zwischenliegende Systeme – und zwei neue Behänge

Sun control: General evaluation method (also suitable for integrated systems) and two new blind types. A general method for realistic performance evaluation of solar control properties of facades with sun‐shading or other solar control systems has been developed. It is particularly designed to be used for venetian blinds. It can be used ‘stand‐alone’ or within building simulation programs. The new method has proven to be of great practical value to planning teams of huge office buildings in Germany, Austria and Switzerland. The method is presented in detail in [4]. It can be used either ‘stand‐alone’ (without building simulation) for comparisons of different facade variants or within building simulation programs. In this publication the extension of the methodology for the case of facades with solar control systems between the panes of an insulating glazing unit (IGU) is presented. Some parts of the proposed methodology could be used in standards (e.g. EN 13363) or to improve the accuracy of building simulation programs which are currently on the market. Practical experience with the new methodology led to insights which are the basis for the design of two new products. These new products are compared with state of the art products in [5] on the basis of the new methodology. We are currently linking the new method with the building simulation program ESP‐r in a project which is funded by the Veluxstiftung.     

Re-Imagining Psychiatric Asylum Spaces through Residential Redevelopment: Strategic Forgetting and Selective Remembrance

The closure of psychiatric asylums across the western world has brought significant amounts of ‘brown field’ land onto the market over the past few decades. Situated on the edge (or former edge) of many cities, these sites have proven attractive for residential redevelopment. Drawing on two case studies from the UK and New Zealand, we consider the implications of such recycling in the built environment for the memory of the former use, asking how redevelopment addresses the stigmatised past of the asylum. We discuss issues associated with the ‘re-imagining’ of heritage buildings and landscapes and examine the extent to which the past is strategically forgotten or selectively remembered in the repackaging of the asylum as housing. We conclude that while stigma continues to cast a shadow over reuse of former asylum spaces, in both case studies impacts seem to dissipate over time. In the UK, this dissipation appears to be enhanced by the presence of policies that cast redevelopment for housing as a source of funding for heritage conservation.     

Sustainable homes,or simply energy-efficient buildings?

Environmental consideration within the Swedish construction sector can no longer be considered marginal. It is here discussed whether the same commitment is extended to facilitate deeper dimensions of sustainability in the provision of housing, beyond simply energy-efficient residential buildings? The paper presents the case of a multi-family ‘green’ residential area being developed in Göteborg, Sweden. An interview study with the seven housing developers building in the area provides primary empirical insights, further complemented by findings from a workshop with architects involved in the project. Conceptualizations of sustainability in housing are explored, based in discourses among these market actors. Issues identified in the inductive data analysis relate to the ambitions set and measures taken in new ‘green’ building, as well as market perceptions of housing standards, lifestyles and household configurations that are reproduced in the built environment. The paper shows that interpretations of sustainability in market-led housing development do not radically challenge the normative and resource intense contemporary ideals surrounding the urban home and that the realization of goals undertaken in the case of Kvillebäcken is generally dependent on economic considerations and market assessments. In conclusion, the paper emphasizes the need to formulate an integrative approach to more holistic sustainable residential environments.     

Making an engine: performativities of building information standards

ABSTRACT

Digitization of buildings requires the systematic handling of a variety and volumes of data. It is a common vision to aim for coordinated homogenization of data structures, enabled by the classification of information. This paper studies the role of building information standards for classification in digitization of the building life cycle. It draws on science and technology studies of information technology standards, big data and building information modelling (BIM) in building research. The approach is based on performativity of standards for information systems, viewing performativity as potentially non-linear and multiple. The five-year design process of a large hospital in Denmark is examined as episodes of performance of the building information standard, particularly one recent standard, the Cuneco Classification System (CCS). The study shows that despite client demands, several building information standards are active over time: an ‘expansive’ design brief process adds user demands and uses room classification. Another process diminishes the design brief more than 50%, with several standards in use. The client’s facilities management system, which performs the structuring of data ‘backwards’ into the design process, makes architects and engineers (but not contractors) use CCS. This fragmentation of performing standards is denoted ‘multiple performativities’ and includes temporal and compartmental performativity.     

Progress report on the UK

A series of special articles is being prepared for the Journal on energy conservation R & D in individual countries represented on CIB working commission W67, ‘Energy conservation in the built environment’. Appropriately, it begins with this article on the UK by Dr. Leach, who is joint co-ordinator of W67 and an Assistant Director of the Building Research Establishment. International studies show that buildings account for 40 per cent of the total primary energy consumption of ten major industrialised nations, and this could be cut by 25–30 per cent without loss of comfort or environmental quality. Against this background, the article discusses the UK energy balance and recent developments in building regulations. Research is reviewed which points to the importance of user behaviour in energy consumption, and to the scope for conservation measures with their economic assessments. A ‘low-energy’ experimental office block design in the UK is also described; its energy consumption could be only half that of similar modern offices.     

Energy efficient design and occupant well-being: Case studies in the UK and India

The purpose of this paper is to demonstrate the relationships between sustainable building design and occupant well-being. It starts with a definition of sustainable design and well-being, and focuses on the relationships between energy performance and occupant feedback. Methodologically it draws on detailed monitoring and surveys of 12 case study office buildings in the UK and India, and the paper uses the data to explore whether energy use and associated CO₂ emissions are correlated to occupant satisfaction and comfort. The results demonstrate that increased energy use in the case study buildings is associated with increased mechanisation (e.g. centralised air conditioning) and reduced occupant control. This reduced control in turn is shown to relate to reduced occupant comfort and satisfaction. Finally, the paper reveals that the reported health conditions of occupants correlates strongly with their levels of satisfaction. The overall conclusion is that energy use in typical office buildings is inversely correlated with the well-being of the occupants: more energy use does not improve well-being.     

Thermal comfort: use of controls in naturally ventilated buildings

A field study of the thermal comfort of workers in natural ventilated office buildings in Oxford and Aberdeen, UK, was carried out which included information about use of building controls. The data were analysed to explore that what effect the outdoor temperature has on the indoor temperature and how this is affected by occupants’ use of environmental controls during the peak summer (June–August). The proportion of subjects using a control was related to indoor and outdoor temperatures to demonstrate the size of the effect. The results suggest that the use of controls is also related to thermal sensation and their appropriate use is a significant part of adaptive behaviour to modify the indoor thermal conditions. The results make it possible to predict the effect of temperature on the ventilation rate in naturally ventilated buildings.     

Solar control: A general evaluation method for facades with venetian blinds or other solar control systems

A general method for realistic performance evaluation of solar control properties of facades for facades with sun-shading or other solar control systems has been developed. It is particularly designed to be used for venetian blinds. It can be used used ‘stand-alone’ or within building simulation programs. The new method has proven to be of great practical value to planning teams of huge office buildings in Germany, Austria and Switzerland. The method is presented in detail in this paper. It can be used either ’stand-alone’ (without building simulation) for comparisons of different facade variants or within building simulation programs. Some parts of the proposed methodology could be used in standards (e.g. EN13363) or to improve the accuracy of building simulation programs which are currently on the market. Practical experience with the new methodology led to insights which are the basis for the design of two new products. These new products are compared with state of the art products in [T.E. Kuhn, Solar control: comparsion of two new systems with the state of the art on the basis of a new general evaluation method for facades with venetian blinds or other solar control systems, Energy and Buildings, in press] on the basis of the new methodology.     

Evaluating positivist theories of occupant satisfaction: a statistical analysis

An explorative statistical analysis of consistent non-domestic building performance studies is conducted non-domestic buildings (n?=?47) to validate the universal positions of comfort widely cited in industry guidance and standards. The Building Use Studies (BUS) methodology for evaluating occupant satisfaction employed by these studies was tested for reliability and the factor structure explored. The reliability of this method was found to be ‘excellent’ and eight latent variables that characterize a hierarchical factor structure induced. Increased visual display unit use and open-plan arrangements were found to be associated with negative occupant perceptions. This suggests that privacy and personal communication may be defining issues for occupant satisfaction, with implications for space planning. Significantly different perceptions towards air quality and conditions in winter were observed between gender and those familiar with their environments were found to have a tendency to hold more negative perceptions more broadly. It has also been found that perceptions towards seasonal conditions may be improved by providing local control to mechanical services. Such insights highlight the limitations of reliance on positivist theory. Hence, it is recommended that high-performance buildings be provided control and management systems that learn from those occupying the building over time, cautiously adapting service provision accordingly.     

Modelling a whole building stock: domestic,non-domestic and mixed use

ABSTRACT

Work on energy use in buildings – in university research, professional practice and government – has tended to draw a broad distinction between ‘the domestic stock’ and ‘the non-domestic stock’. A further tendency has been to focus attention on types of non-domestic buildings devoted to single uses (e.g. offices, shops or hospitals). This paper reports an empirical research programme in which the complete building stock in large areas of England and Wales is comprehensively represented in great detail, using a new method and model called 3DStock. The model breaks down activities by floor level and within each floor of every building. The results show that the extent of mixing of uses is much greater than has previously been acknowledged, especially towards the centres and in the older parts of towns and cities. These mixed-activity buildings are sometimes relatively simple combinations of domestic and non-domestic, e.g. urban retail with flats above, while others are complex mixtures of different non-domestic activities. The model can be used to investigate how these complex relationships influence energy use. It is argued that, at the larger scale, explicit account needs to be taken of the mixing of uses in future stock models for research and policy-making.     

Simulation and visualization of energy-related occupant behavior in office buildings

In current building performance simulation programs, occupant presence and interactions with building systems are over-simplified and less indicative of real world scenarios, contributing to the discrepancies between simulated and actual energy use in buildings. Simulation results are normally presented using various types of charts. However, using those charts, it is difficult to visualize and communicate the importance of occupants’ behavior to building energy performance. This study introduced a new approach to simulating and visualizing energy-related occupant behavior in office buildings. First, the Occupancy Simulator was used to simulate the occupant presence and movement and generate occupant schedules for each space as well as for each occupant. Then an occupant behavior functional mockup unit (obFMU) was used to model occupant behavior and analyze their impact on building energy use through co-simulation with EnergyPlus. Finally, an agent-based model built upon AnyLogic was applied to visualize the simulation results of the occupant movement and interactions with building systems, as well as the related energy performance. A case study using a small office building in Miami, FL was presented to demonstrate the process and application of the Occupancy Simulator, the obFMU and EnergyPlus, and the AnyLogic module in simulation and visualization of energy-related occupant behaviors in office buildings. The presented approach provides a new detailed and visual way for policy makers, architects, engineers and building operators to better understand occupant energy behavior and their impact on energy use in buildings, which can improve the design and operation of low energy buildings.     

Climatic and internal factors affecting future UK office heating and cooling energy consumptions

There is a large consensus concerning the expected trend, if not the magnitude of change, of the UK climate in the coming decades [Climate Change 2007: Impacts, Adaptation and Vulnerability, Intergovernmental Panel on Climate Change, April 2007]. This study aims to quantify how such changes will have a direct effect on heating and cooling energy use in future office environments (i.e. by the year 2030). When considering future offices, it is also necessary to account for a change in the small power and lighting equipment being used, in this case by assuming an improved efficiency in both categories. This will also have a significant effect on the balance of heating and cooling an office. Furthermore, the subtle effect of a change in location within the UK can affect results further, with northern cities having substantially higher heating loads (and lower cooling loads) than southern locations. Such factors can influence approaches towards reducing future office energy demands and, in some cases, be the difference between a heating-dominated or cooling-dominated building. This study should also inform future choices for supplying energy to office buildings, in particular microgeneration options. It confirms the importance of dealing with demand-side changes before assessing the supply-side opportunities, with buildings having very different heating and cooling needs post-refurbishment. The study also highlights the importance, and possibilities, of adapting to future climates, and the benefits of promoting heating-dominated buildings instead of cooling-dominated.     

Sol-air temperature and daylight illuminance profiles for the UKCP09 data sets

To provide information on climate change, the UK Climate Impacts Programme (UKCIP) provided the latest UKCP09 data to a resolution of 5 km square grids for the UK. Those data sets were used in this study along with the historical measured data for two locations—Bracknell (London) and Edinburgh—to critically analyse the likely changes that may occur in the sol-air temperature and daylight illuminance profiles. These parameters have an important bearing on the design and function of buildings and building services.     

Optimising the installation costs of renewable energy technologies in buildings: A Linear Programming approach

This paper demonstrates how Linear Programming (LP) can be applied to assist in the choice of renewable energy technologies for use in buildings to meet CO₂ emissions reduction targets. Since there are many possibilities for combining different renewable technologies, the capital costs associated with the installation of one or more renewables can vary widely. In terms of capital investment the preferred solution will be the one at least cost, and LP provides an effective way to find this minimum through the so-called “objective function”. This project has used “lp_solve”, a free-source Mixed Integer Linear Programming solver that has been embedded in a Microsoft Excel application called Carbon emissions And Renewables for Building OPtimisation Toolkit (CARB-OPT) developed by RES Ltd in collaboration with London South Bank University (Renewable Environmental Services Ltd. (RES) is the environmental consultancy of Long and Partners Engineering Group. RES is currently involved in a Knowledge Transfer Partnerships (KTP) project in conjunction with the Faculty of Engineering, Science and the Building Environment (ESBE) at London South Bank University). This paper reports the application of this LP optimisation process for an office building case study with four alternative combinations of renewables. The process showed the technology mix that would lead to the smallest investment needed to comply with UK Building Regulations requirements and regional planning targets. In addition, the process offers a robust methodology to test the impact that the key assumptions may have upon the optimum solution.     

Frameworks for defects diagnosis

As one with long experience and much expertise in identifying causes of dampness in buildings, the author became the ‘human expert’ for ‘knowledge mining’ by the knowledge engineers working on an expert system for the subject. The insights he thus gained into diagnostic thinking are reflected here in outlining a framework for systematic diagnosis, first of dampness in buildings and then of building defects in general. Jim Smith is a member of the Building Research Advisory Service of BRE, UK.