A CHECKLIST FOR SUSTAINABLE BUILDINGS
William Scott
Introduction
It is often tempting to evaluate the “sustainability” of a building solely in terms of a single feature, perhaps the Building Energy Rating (BER) or use of particularly eco-friendly materials. BER can provide an excellent indicator of the theoretical energy performance of a building in use. The selection of appropriate materials is obviously desirable. However evaluation on such simplistic bases ignores many other aspects that are critical to a proper evaluation of the sustainability of a building.
A building should respond to the three classic demands of sustainability; social, environmental and economic. If a building fails to pass scrutiny in one of these areas, it is unlikely that it is a truly sustainable building.
The RIAI Sustainability Task Force (STF) is responsible for the assessment of submitted projects for the annual RIAI Sustainability Award. In 2007 that assessment was based on an objective checklist of criteria. The checklist has since been developed to also become a useful tool for designers when they evaluate their brief and develop a design. For this reason the checklist is now being made generally available to facilitate the design and construction of every building. It is hoped that this article will assist this process.
The Need for a Checklist for Sustainable Buildings
There is a range of systems available for evaluation of buildings, often most suited to a particular sector of building types; BREEAM, LEED, Ecohomes, BER and the like. These systems give an excellent response to various ranges of indicators. There is usually a significant expense and a very considerable effort involved in such assessments. At the other extreme, all architects have seen buildings being hailed as “green”, in a manner that may be scarcely credible, with no obvious basis to support such claims.
Most practitioners will welcome the availability of a free, quick and relatively simple checklist that enables a preliminary evaluation of the sustainability of a building. A subsequent in-depth assessment will of course be appropriate in many cases, meriting the expense and effort involved in a formal evaluation of the type mentioned.
The evaluation of an architectural competition on sustainability of buildings must be completed as objectively and comprehensively as is possible. Availability of a checklist allows a simple, quick and consistent evaluation of entries for the RIAI Sustainability Award.
The Origin of the Checklist
Bill Gething and Bill Bordass published an article in 2006 describing a Rapid Assessment Checklist for Sustainable Buildings[1]. The article describes the development of the checklist, drawing from earlier evaluation systems and from original research, and its use in the RIBA Sustainability Award in 2005. Sally Starbuck of RIAI STF approached the authors and the RIBA and gained their generous permission to utilise and adapt the work to suit the purposes of RIAI. Where such modifications have taken place, the STF has attempted to maintain the core principle of using the checklist to enable a broad range of evaluation with consistency, simplicity and clarity of use. The resulting Checklist for Sustainable Buildings is now published on the RIAI website[2].
Exploring the checklist
The checklist places the assessment topics in 11 main groupings, which are considered under headings appropriate to the design and construction process. The topics are listed with some brief comments.
The CONTEXT section considers the Choice of the site, which will have a significant effect on the immediate and lifelong environmental impact of the building. Constant expansion of the built environment is obviously ultimately unsustainable. Buildings that are remote from central resources carry large and continuing burdens associated with transport and servicing. However, decisions about the choice of site are not always within the control of the architect.
The DESIGN CHOICES section considers matters that generally fall within the control of the architect. The key issues considered are the Use of the site (dealing with the effect on the immediate site and surroundings of the building and its usage), Building form (dealing with the key issues relating to the shape and location of the building) and Use of materials.
The OUTCOMES section considers the results of the decisions of the architect and their team. The checklist occasionally requires a record of the normal or benchmark standards for a building type (as well as the source of that benchmark) as well as the design or target standard achieved (and the source / verification of the data). Key issues examined are the Functionality or useability of the building as well as the Indoor environment achieved. Energy, CO2 and utilities are considered in some detail in this very critical area of performance. Specific objective information is required concerning primary and delivered energy usage for the building. Much of this information will be available from a standard BER assessment or from specialist modelling of large buildings. The last part of this section deals with Emissions of all kinds from the building.
The DESIGN AND CONSTRUCTION PROCESS section considers a range of issues, some of which merit description. Briefing and Design Reviews: Sustainability deals with the appropriate and timely consideration of sustainability throughout the process. Considerate Constructor is a concept that may be unfamiliar to many in Ireland. It derives from a UK code of behaviour[3] for builders and aims to reduce negative impact of construction operations on the environment, the public and the workforce. Participation by a builder also gains points during BREEAM assessment. In the Irish context, and hopefully pending the development of such a local scheme, the response must relate to the deliberate and recorded response of a contractor to these issues. Incorporating Post Occupancy Evaluation (POE) involves the stated commitment to, or actual completion of, a POE to analyse the results achieved in a completed building and the response of building occupants and users over a broad range of issues.
The section ACHIEVED PERFORMANCE will only be used for buildings that are in use long enough to yield useful results. Where this is the case, as-built results (as opposed to design or intended) should be utilised in some of the earlier sections of the checklist, with a declaration to this effect in this section.
A SUPPLEMENTARY NOTES section allows the addition of relevant information which the checklist has not explored.
Finally, the RIAI seeks a response to the checklist from members and invites comment in a Feedback section on the forms submitted for the competition.
Use of the Checklist
The checklist form is filled out as follows:
-Enter the title of the building.
-Describe your response to each criterion. If the criterion is not appropriate to the project, state why.
-Apply your own numerical rating to the criterion ... -2 to +3 as appropriate. Guidelines to numerical ratings are described on the form.
-Enter the standard performance benchmarks and the performance as targeted or as actually achieved(where appropriate).
-Identify the source of all data.
-Add supplementary comments at the foot of the sheet and attach relevant material.
Where the procedure is carried out by the architect for their own use, it will be useful to refer to the checklist through the brief and design stages. A record should normally be retained.
Where the checklist is used as (an essential) part of the competition for the RIAI Sustainability Award, it should be submitted as a part of the competition documentation. Competitors are asked to use the checklist to “self-assess”.
The competition jury will use the submitted checklist as a source of
-information leading to understanding of design strategies and concepts,
-factual information that might not otherwise be apparent from presentation documents,
-hard performance data in a format that enables fair comparison.
The process of evaluation of the RIAI Sustainability Award is carried out in the following manner:
-Blank checklists are used by each jury member, who independently evaluate buildings based on submitted information.
-Assessments are coordinated to compile a shortlist.
-The shortlisted projects are then evaluated jointly by the jury.
-An award winner is selected and the award citation for the project is agreed.
It is recognised that individual topics on the checklist will be of greater or lesser significance in various buildings. In some cases, a response may not be appropriate; this should be stated. For this reason, there is no attempt to apply a weighting to any topic. “Marks” will not be “added up”. Instead, individual numerical and written responses will be considered in the context of the particular building, leading to an overall opinion on the sustainability of the building.
Further Development
The STF views the checklist is a work-in-progress. Some areas of importance are not considered. For example, economics has been left out of the checklist at present as it has not yet been agreed how to request and use this information. While most buildings are the result of rigorous financial restrictions, there is a pattern emerging of considerable and sometimes inappropriate expenditure on “green” installations. An evaluation of cost could illustrate the distinction between judicious expenditure on sustainable solutions and a display of eco-bling! Other areas for future consideration may include topics as diverse as building conservation, universal accessibility and the like. However, it is felt that appropriate reference to the current checklist will help every architect achieve a critical and realistic review of their work and facilitate the competition process.
It would be of considerable benefit to the award process if data on actual energy used was made available. It is anticipated that future entrants will be asked for a commitment (if requested) to subsequently submit actual Energy / CO2 data for one year of use of the building. This real data will allow comparison to design data. The actual energy data will be requested for those schemes that are either exhibition or award winning projects. The actual and design data will be displayed at the exhibition the following year with an explanatory commentary. This process could become a valuable source of information on performance, specification and system selection criteria.
The STF would be very pleased to receive comment, critical or otherwise, in open forum in AI, by submission to STF or in the feedback section of the checklist during competitions. Future refinement of the checklist, following those comments, will help architectsmeet the challenges posed by the delivery of truly sustainable buildings.
[1] Building Research and Information (2006), 34 (4), 416-426, Gething & Bordass
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