Parametric life cycle analysis for the optimization of building construction regarding its grey CO2 emissions and operational energy demand

Abstract

To achieve climate protection targets, energy and CO2 emissions should become driving forces in the building design process. However, quantifying operational energy and gray CO2 emissions over the entire life cycle of a building is complex and data intensive. The classic design methodology is unsuitable for a holistic view of sustainability aspects. The parametric design methodology makes it possible to take many parameters into account and to compare a large number of design variants. This paper shows the workflow of a parametric building simulation. The workflow consists of a combination of life cycle analysis and dynamic building energy simulation. The life cycle analysis quantifies the gray emissions from the production, maintenance, and disposal of a building. The dynamic building energy simulation determines the operational energy demand of the building, from which the CO2 emissions during operation can be derived. The simulation is modeled and carried out using the tools Rhinoceros 3D, Grasshopper, Bombyx, Honeybee and Colibri. The workflow is applied to an existing reinforced concrete building in Germany. The combination of building components (exterior walls, ceilings, roof, and façade) in different construction methods (reinforced concrete construction, massive timber construction, and timber frame construction) results in 48 design variants. The results of the simulation show optimization potentials for some timber construction variants compared to the existing reinforced concrete construction regarding CO2 emissions over the entire life cycle of the building. With the developed workflow, different design solutions can be compared and CO2 emissions can be reduced over the entire life cycle of a building.