How design concepts influence carbon footprints of load bearing structures

Abstract

In recent years, it has become essential to consider the total carbon footprint of a construction project. Commonly, the question has been: ’What is the best material to be used in this context?’ In this paper we argue that this question is incomplete, not taking the complexity of design choices into consideration. This paper intends to share light on how to analyse some factors that influence the construction of buildings in order to contribute to climate change mitigation, taking this complexity into consideration. Calculation of fossil greenhouse gas (GHG) emissions for two load-bearing structures for office buildings in 4, 8 and 16 storeys with equal functional requirements; e.g. load bearing capacity, acoustic performance, fire resistance and adaptability are addressed. The main materials for the load-bearing structures are cross laminated timber (CLT) elements and precast concrete elements respectively. The result show that one cannot on a general basis conclude that either type of load-bearing structure cause less fossil GHG emissions. It is always important to consider the building design, functionality as well as external conditions such as location when considering different load-bearing structure materials.