Towards a Framework for Supporting Sustainable Building Design: A Case Study of Two Credits Over Evolving Rating Standards
It is becoming increasingly relevant that designs address sustainability requirements. The objectives of any sustainable design are: to reduce resource depletion of energy, water, and raw materials; prevent environmental degradation caused throughout the building lifecycle; provide a safe, comfortable and healthy living environment. Currently, the sustainability of a building is judged by standards codified in a rating system. (1) Although compliance with a sustainability rating system is not mandatory, increasingly, it is becoming a goal that many designers and authorities would like to achieve. However, there are impediments to the pervasive use of sustainable design rating systems. 1. Certification is expensive. ( 2 ) It is labor intensive, involving large volumes of data aggregation, information accounting and exchange, which, can be a deterrent to designers and the design process. 2. Ratings systems are periodically reviewed; as our understanding increase and technology improve, sustainability requirements on designs become more extensive and, sometimes, more stringent. (3) 3. Sustainable building design rating tools are not readily integrated into the design process whereby the design solution can be developed by different disciplines. 4. The design information model associated with a building may not contain the data (attributes) necessary to evaluate its design. 5. Information is disparate and distributed—requiring it to be supplemented, augmented from various sources, and managed for the different stages of a building design process In practice, designers tend to employ commercial (and reasonably stable) design tools, making it imperative to develop an approach that utilizes information readily and currently available in digital form in conjunction with rating system requirements. This research focuses on supporting sustainability assessment where designers need to evaluate the information in a design in order to fulfill sustainability metrics. The main research objective is an approach to integrating sustainability assessment with a design environment. This comprises: identifying informational requirements from rating systems; representing them in computable form; mapping them to information in a commercial design tool; and assessing the performance of a design. An overall framework for organizing, managing and representing sustainability information requirements is developed as the demonstrator. Case study of an actual project demonstrates the flow of information from a commercially available building information modeler and a sustainable building rating system. The process developed bridges sustainability assessment requirements with information from the model for preevaluation prior to submission for certification. Contributions include a technical implementation of sustainable design assessment for pre assessment through a process of identifying information availability, augmentation, representation and management focused on two credits (Reduce indoor water use and Minimum energy performance) over evolving rating standards, namely (LEED 2.1, LEED 2009 and LEED v4). These contributions are intended to enable designers, stakeholders, contractors and other professionals to communicate strategies and make informed decisions to achieve sustainability goals for a project from design through to operation.
(1) Design choices are validated, by measuring design performance against criteria specified by the rating system. See Chapter 2: Research Background. (2) “Shame on you for perpetuating this myth that green design costs more even if integrated properly. LEED certification does, but green design need not.” (Kats, 2010) (3) “Sustainability is not static–it is iteratively changing, based on knowledge that connects science and design.” (Williams, 2007)