Building Morphology, Transparence, and Energy Performance
Eighth International IBPSA Conference
Eindhoven, Netherlands August 11-14, 2003
BUILDING MORPHOLOGY, TRANSPARENCE, AND ENERGY PERFORMANCE
Werner Pessenlehner and Ardeshir Mahdavi Department of Building Physics and Human Ecology Vienna University of Technology Vienna, 1040 - Austria
ABSTRACT
Certain energy-related building standards make use of simple numeric indicators to describe a building 's geometric compactness. Typically, such indicators make use of the relation between the volume of a built form and its surface area. The indicators are then used along with information on the thermal transmittance of the building enclosure elements to evaluate the degree to which a building design meets the relevant thermal insulation criteria. Using extensive parametric thermal simulations, this paper examines the reliability of such simple compactness indicators for energy-related evaluative assessments given that buildings with the same compactness attribute could differ in enclosure transparence, orientation, and morphology.
orientation of a building (e.g., south orientation versus west orientation) does not change its compactness, but may affect thermal performance given changes in insolation and shading conditions. Given these critical considerations, the present study examines the reliability of geometric compactness indicators for energy-related evaluative assessments based on extensive parametric thermal simulation studies. We explore, via variations of building morphology and transparence (the size and distribution of transparent enclosure components), the limitations of exclusive reference to shapes compactness in thermal performance assessment guidelines and standards. Specifically, we demonstrate the thermally relevant interdependencies between compactness and transparence for a specific climatic context and for a morphologically varied class of residential building shapes.
1. INTRODUCTION
Prescriptive building energy codes often set minimum
Eindhoven, Netherlands August 11-14, 2003
BUILDING MORPHOLOGY, TRANSPARENCE, AND ENERGY PERFORMANCE
Werner Pessenlehner and Ardeshir Mahdavi Department of Building Physics and Human Ecology Vienna University of Technology Vienna, 1040 - Austria
ABSTRACT
Certain energy-related building standards make use of simple numeric indicators to describe a building 's geometric compactness. Typically, such indicators make use of the relation between the volume of a built form and its surface area. The indicators are then used along with information on the thermal transmittance of the building enclosure elements to evaluate the degree to which a building design meets the relevant thermal insulation criteria. Using extensive parametric thermal simulations, this paper examines the reliability of such simple compactness indicators for energy-related evaluative assessments given that buildings with the same compactness attribute could differ in enclosure transparence, orientation, and morphology.
orientation of a building (e.g., south orientation versus west orientation) does not change its compactness, but may affect thermal performance given changes in insolation and shading conditions. Given these critical considerations, the present study examines the reliability of geometric compactness indicators for energy-related evaluative assessments based on extensive parametric thermal simulation studies. We explore, via variations of building morphology and transparence (the size and distribution of transparent enclosure components), the limitations of exclusive reference to shapes compactness in thermal performance assessment guidelines and standards. Specifically, we demonstrate the thermally relevant interdependencies between compactness and transparence for a specific climatic context and for a morphologically varied class of residential building shapes.
1. INTRODUCTION
Prescriptive building energy codes often set minimum
References: Heindl, W., Grilli, P.V. 1991. On Establishing Standards for the Overall Heat Transfer Coefficient of Buildings, CIB-W67-Workshop 1991, Vienna. Mahdavi, A., Gurtekin, B. 2002a. Shapes, Numbers, and Perception: Aspects and Dimensions of the Design Performance Space, Proceedings of the 6th International Conference: Design and Decision Support Systems in Architecture, The Netherlands, ISBN 90-6814-141-4. pp 291-300. Mahdavi, A., Gurtekin, B. 2002b. Adventures in the design-performance space, Proceedings of the 16th European Meeting on Cybernetics and System Research. Vienna, Austria. Volume 1, pp. 269-274. Mahdavi, A., Mathew, P. 1995. Synchronous generation of homologous representations in an active, multi-aspect design environment, Proceedings. of IBPSA Conference. 31(5), pp 522528. Mahdavi, A., Brahme, R., Mathew, P. 1996. The "LEK"-Concept and its Applicability for the Energy Analysis of Comercial Buildings, Building and Environment, 31(5). pp 409-415. ÖNORM 2002. ÖNORM B 8110-1: Wärmeschutz im Hochbau – Anforderungen an den Wärmeschutz und Nachweisverfahren, Österreichisches Normungsinstitut, Wien, 29. Januar 2002. ÖNORM 1999. ÖNORM B 8110-3: Wärmeschutz im Hochbau – Wärmespeicherung und Sonneneinflüsse, Österreichisches Normungsinstitut, Wien, 1. Dezember 1999. - 1024 1032