Energy Performance Indicators in the Swedish Building Procurement Process

Abstract

Abstract:In Sweden, all new buildings need to comply with the National Board of Housing, Building and Planning's requirement on specific purchased energy (kWh/m 2 ). Accordingly, this indicator is often used to set design criteria in the building procurement process. However, when energy use is measured in finished buildings, the measurements often deviate significantly from the design calculations. The measured specific purchased energy does not necessarily reflect the responsibility of the building contractor, as it is influenced by the building operation, user behavior and climate. Therefore, Swedish building practitioners may prefer other indicators for setting design criteria in the building procurement process. The aim of this study was twofold: (i) to understand the Swedish building practitioners' perspectives and opinions on seven building energy performance indicators (envelope air leakage, U-values for different building parts, average U-value, specific heat loss, heat loss coefficient, specific net energy, and specific purchased energy); and (ii) to understand the consequences for the energy performance of multi-family buildings of using the studied indicators to set criteria in the procurement process. The study involved a Delphi approach and simulations of a multi-family case study building. The studied indicators were discussed in terms of how they may meet the needs of the building practitioners when used to set building energy performance criteria in the procurement process.

Key factors hindering sustainable procurement in the Brazilian public sector: A Delphi study

“…Data were collected through a Delphi exercise that was used to identify the main barriers affecting SPP in the Brazilian public sector context. This approach allows for a deeper analysis of the subject [22] and contributes to the formation of a specialized collective opinion [55]. A five-point Likert scale was used to collect opinions from sustainability experts in order to identify, rank, and prioritize the barriers regarding to their level of impact from the perspective of professionals with recognized competence.…”

“…The Delphi method was developed in 1962 by Norman Dalkey and Olaf Helmer [61]. It consists of a group process [62] in which collective conclusion is considered more trustworthy than individual opinions [55]. The method is structured from questionnaire rounds with knowledge being transferred between the participants through feedback and survey readministration [55], which requires time commitment and a certain willingness on the part of the individuals to review their own points of view [63].…”

“…Another feature of the Delphi approach is that information can be exchanged until a satisfactory degree of consensus is reached [55], without requiring participants to meet in person [64]. In fact, maintaining the anonymity of individual responses during the process is even desirable [63], as it allows participants to express their opinions more transparently and without any fear of being judged by other members of the group.…”

“…Given the apparent complexity of SPP, researchers chose to use in the Delphi study a panel of carefully selected sustainability experts in order to reduce results uncertainty and improve reliability. The selection criteria involved indicators of academic and professional training, years of experience working with the SPP [55], publications in the field [25], presentations made at national and international conventions [25], and availability to participate [14]. 23 recognized sustainability specialists with extensive professional experience and representing a range of sectors, such as academics, public sector professionals and consultants, were initially invited to engage in the study.…”

Summer performance, comfort, and heat stress in structural timber buildings under moderate weather conditions

“…As widely reported, energy used in various buildings accounts for about 30 per cent of the annual sum of energy used in the world (IEA, 2012). Also, various buildings are likely to use additional energy than predicted at the early stage of building design as a result of different contributing factors such as Summertime temperatures, temperature swing and low thermal mass in buildings (Adekunle, 2014;Allard et al, 2017). The frequency of high temperatures in Summer months has been reported as one of the significant issues to examine and address in sustainable buildings such as timber buildings (Adekunle and Nikolopoulou, 2016a).…”