Evaluation of Building Forms: An analytical study on environmental impact and energy performance

Abstract

The study consisted of an analysis of buildings with different forms, based on residential archetypes, and an assessment of their energy demand and environmental impact, for Swedish conditions. A Shoebox Study was performed, including seven building archetypes, developed by assembling basic units, shaped like a shoebox. A number of form-defining properties was selected based on the literature review, allowing to describe the form of buildings analysed in the study in a clear and consistent way. The energy performance was determined using Climate Studio plug-in in the Rhinoceros software. The environmental impact was assessed using One Click LCA, incorporated into the Revit environment. It was aimed to find a correlation between the building form, energy performance and environmental impact. The correlation was assessed while focusing on a realistic approach to the design of buildings with varying shapes but constant living floor area, referred to as residential space floor area, and when analysing an impact of the scale of buildings with a constant shape but varying living floor area. Subsequently, a Case Study was performed, where a form of a building used in a real-life project developed by Arkitema company, was assessed. The objective was to determine if a correlation between the building’s form, energy demand and environmental impact, established in the Shoebox Study, can allow to predict the performance of a building with a different form. The prediction was carried out by the means of mathematical proportion. Subsequently, simulations of the energy performance and environmental impact calculations were performed for the Case Study and the results compared with the predicted values to assess the accuracy of the prediction. Ultimately an assessment of the relationship between the building form, the energy demand and GWP was done for the Shoebox Study and Case Study together, in order to analyse the correlation in the context of a real-life building form. Two separate assessments were performed with the results expressed per m2 of the heated floor area and per m2 of the residential space floor area and the outcomes compared to illustrate the impact of the service spaces, included in the heated floor area, on the energy demand and global warming potential of considered buildings.

Popular Abstract

The study focuses on investigating a co-relation between the building’s form, its energy demand and environmental impact, in relation to different residential typologies. Moreover, a possibility of using the form factor to predict the building’s performance is explored.
In the face of rapidly progressing climatic changes, it has become crucial to focus our efforts on reducing the impact that we, as humans, have on the quality of life on earth and the planet’s gradual degradation. Among a myriad of factors negatively impacting the environment, the green-house gasses emissions resulting from the energy production and other industrial processes are considered leading issues. As it is estimated that the building industry is responsible for about 40% of the global emissions of green-house gasses and about 35% of the global energy demand, it is considered a priority to undertake steps needed to decrease those numbers.
It is perceived, based on literature, that by assessing the building’s form, the energy demand and environmental impact of a building can be accounted for already in the early design stage. However, with sparce research regarding the relationship between the three forementioned features, no clear conclusion could be made regarding the influence of the form on the energy demand and the environmental impact of a building simultaneously. The objective of this paper was to address that research gap.
The Shoebox Study was developed for the climatic conditions of Malmö, Sweden, where a basic unit, shaped like a shoebox, was multiplied and assembled in different shapes. Performance of the “shoebox” buildings was then assessed in terms of energy demand and global warming potential (GWP). The Shoebox Study findings allowed to determine a correlation between the building’s form, defined by a form factor and a heat-loss form factor, it’s energy demand and environmental impact. It was, however, observed that varying inputs in the analysis, dependent on the building character and corresponding values in the building standards, influence the results, making it more difficult to establish a clear relationship. However, the trend representing the best-performing and worst-performing building was proportional to the value of form factor and heat-loss form factor in all instances.
Based on the Shoebox Study findings and a defined form of a building used in a real-life project, the prediction of energy demand and GWP was carried out. Having simulated and compared the actual energy demand and environmental performance of the considered building, it was determined that, based on the value of the form factor, and the outcomes from the Shoebox Study, a relatively accurate prediction of the results could be made.
When comparing the results expressed per m2 of the heated floor area with the results expressed per m2 of the liveable floor area, excluding any common spaces in the buildings, it could be observed that in the second representation of the results, the energy demand as well as GWP were much higher for the buildings where the heated floor area was not equal to the liveable floor area. It was noted that the form-factor and heat-loss form factor where no longer proportional to the building’s performance when the liveable space was considered.
Ultimately it was concluded that, when considering the results per heated floor area and accounting for any changes to the design or varying standards requirements, the form of the building can be assessed to account for the energy demand and environmental impact in the early design stage. Architects and engineers can use the form factor as a tool in the assessment.

• author: Mutatkar, Shivani and Ciepiela, Marianna
• supervisor: Ulla Janson; Karin Farsäter
• organization: Division of Energy and Building Design; Department of Architecture and Built Environment
• course: AEBM01 20221
• year: 2022
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Building form, Form factor, Energy demand, Environmental impact, Global warming potential
• language: English
• additional info: Collaboration on the master thesis with the company 'Arkitema' based in Stockholm, Sweden.
• id: 9088322
• date added to LUP: 2022-06-14 09:24:14
• date last changed: 2022-06-14 09:24:14