A Simplified Method for Evaluating Building Sustainability in the Early Design Phase for Architects
Jernej Markelj 1,*, Manja Kitek Kuzman 2, Petra Grošelj 2 and Martina Zbašnik-Senegačnik 1
1 Faculty of Architecture, University of Ljubljana, Zoisova cesta 12, 1000 Ljubljana, Slovenia; E-Mail: martina.zbasnik@fa.uni-lj.si
2 Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana, Rožna Dolina, cesta VIII 34, 1000 Ljubljana, Slovenia; E-Mails: manja.kuzman@bf.uni-lj.si (M.K.K.); petra.groselj@bf.uni-lj.si (P.G.)
* Author to whom correspondence should be addressed; E-Mail: jernej.markelj@fa.uni-lj.si; Tel.: +386-1-2000-777.
External Editor: Marc A. Rosen
Received: 2 September 2014; in revised form: 20 November 2014 / Accepted: 25 November 2014 / Published: 2 December 2014
Abstract: With society turning increasingly to sustainable development, sharper demands are being made concerning energy efficiency and other properties that mean reductions in the negative effects of the building on the environment and people. This means that architects must have a suitably adapted solution already in the early design phase, as this has the greatest influence on the final result. Current tools and methods used for this are either focused only on individual topics or are too complex and not adapted for independent use by architects. The paper presents a simplified method for evaluating building sustainability (SMEBS) which addresses these needs. It is intended as a tool to aid architects in the early project planning phases as it allows a quick evaluation of the extent to which the demands of sustainable building are fulfilled. The method was developed on the basis of a study of international building sustainability assessment methods (BSAM) and standards in this field. Experts in sustainable construction were invited to determine weights for assessment parameters using the analytical hierarchy process (AHP). Their judgments reflect the specific characteristics of the local environment.
Keywords: building; architect; sustainability; evaluation; analytic hierarchy process
OPEN ACCESS
1. Introduction
We are becoming increasingly aware that the quality of building design, manner of construction and operation of buildings are key factors that influence the implementation of sustainable development. This is why in the past two decades numerous building sustainability assessment methods (BSAM) have been developed throughout the world [1]. They are used to assess and present the quality of the building with the help of criteria from different fields. Initially, most emphasis was placed on the evaluation of environmental topics such energy consumption, pollution from emissions, water use and biodiversity. However, in recent years, with the development and defining of international standards in this area, BSAM increasingly take into account other aspects: functionality, economical aspects, accessibility and technical characteristics. The building is increasingly being treated in the entirety of its life-cycle: from the phase of acquisition of raw materials, the production of construction materials and components, the actual construction process of the building, its use and maintenance and if applicable also its demolition and disposal. Due to the comprehensive and clear analysis of a particular building, BSAM are becoming increasingly popular, and in certain countries even compulsory, in public procurement, where funds must be very efficiently invested and a high level of transparency is demanded. Chambers and institutes of engineers and architects throughout the world increasingly recommend using BSAM in their guidelines for optimal project planning. They are also demanded by numerous private investors in building projects who demand that the principles of sustainable construction are clearly complied with (and hence that the targets of sustainable development are pursued). In certain countries, the use of BSAM for projects financed by public funds is already compulsory. In practice, this means that architects must have a suitably adapted project plan already in the early design phase, as this has the greatest influence on the final result. In early design phase the most important building design decision that influence the sustainability are set: position and orientation of the building on the parcel, its form, type of structure with material, internal layout, building envelope with its transparent parts as well as the type of mechanical systems for heating, cooling, ventilation and air-conditioning. In order to optimize the project according to the principles of sustainable construction and energy efficiency, these early stages of design should comprise the following [2]:
(1) The form should be chosen depending on the site-specific characteristics, functional requirements, orientation and sunlight, the thermal hierarchy of spaces and the potential for natural ventilation.
(2) Building envelope design should be optimized (heat insulation, window openings, illumination of spaces and shading, thermal mass) and the choice of active systems should be given special consideration (heating, cooling, mechanical ventilation, solar collectors, PV modules).
(3) Tools for checking the suitability and performance of the design solution should be used (acquisition of key information about the planned building and its characteristics in the phase of use).
(4) The acquired results should be properly interpreted and the design optimized accordingly (back to Step 1).
In the phases that follow the early design stage, some aspects can be improved, but only to a certain extent. Alongside the environmental indicators, such as the amount of energy that will be needed for
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the construction and operation of the building, the level of harmful gas emissions, water use etc., it is also necessary to include social and economic aspects in evaluating the quality of the design solution [3,4]: the living comfort inside the building, its functionality, the total cost for the entire life cycle of the building, integration in the neighborhood, public involvement and location. However, maintaining control over all the aspects connected with sustainability in building construction and estimating their influence on the final result while still in the early design phase is quite challenging. There is, therefore, a need for an information tool that will show in a comprehensive manner how a particular design is addressing a variety of different criteria important for achieving a more sustainable solution. It should be simple enough to allow the architect himself to perform a quick evaluation of the sustainability of the design in the early planning stages. As such it would be an important aid for architects, as leaders of the building planning teams, to optimize the design solution during process.
The main purpose of this article is therefore to present the development of a simplified method for evaluating building sustainability (SMEBS) in the early planning phases for architects. The stages of the research are outlined in Figure 1. In the first stage (Section 2) we analyzed the literature about building performance tools that are a support in planning and comprehensive building sustainability assessment methods (BSAM). The advantages and disadvantages of existing BSAM are explained and the reasons for a simple method for evaluating building sustainability are presented. On this basis a model of structured parameters for building sustainability evaluation in the early design phases is developed (Section 3). For determining the significance of individual parameters in the model experts from the field of sustainable construction are surveyed (Section 4). In the survey, the analytical hierarchy process (AHP), which enables complex decisions to be made by simplifying the decision-making process, is used for allocating parameter weights. The model and acquired parameters’ weights (Section 5) are used to develop a SMEBS, which allows a quick evaluation of the extent to which the demands of sustainable building are fulfilled. Based on these results the architect can optimize the design project accordingly. It is made as an Excel based tool and is intended for use in the local context (Section 6).
Figure 1. Workflow diagram.
2.