Using a budget approach for decision-support in the design process

A Hollberg,G Habert,T Lützkendorf

doi:10.1088/1755-1315/323/1/012026

Abstract

The use of Life Cycle Assessment (LCA) during the design phase can help to improve the environmental performance of buildings. However, designers and clients find it difficult to set environmental performance targets and interpret the results obtained through LCA in order to improve the building design. Therefore, performance levels or benchmarks are needed that provide design guidance towards reducing the environmental impacts of buildings in the life cycle. This paper uses a dual benchmark approach. The main concept consists in combining building-related top-down targets with building component-related bottom-up benchmarks. The overall top-down targets per capita and year are derived from the capacity of the global eco system. The bottom-up benchmarks for building elements are calculated following a best-in-class (top 5%) approach. A workflow of applying these benchmarks is proposed. It provides guidance on how to optimize the environmental performance of a building and its components efficiently by differentiating between material and design-related options. The approach is exemplified by means of a case study of a multi-family house.

Highlights

Until now, the efforts to reduce greenhouse gas (GHG) emissions in the building sector mainly focused on the use phase of buildings
As Life Cycle Assessment (LCA) is more commonly applied to assess the environmental performance of buildings, different actors have a need for LCA-based benchmarks
Investors, building owners and public funding institutions need them to define environmental performance targets and architects need them for design guidance

Summary

Introduction

The efforts to reduce greenhouse gas (GHG) emissions in the building sector mainly focused on the use phase of buildings. Design decisions largely determine the environmental performance of the building [1] for the 50 to 100 years. Designers are key actors for reducing global GHG emissions during the life cycle of individual buildings. Life Cycle Assessment (LCA) is a suitable method for evaluating the building’s environmental performance, currently, designers often find it difficult to interpret the LCA results and use them to improve the building design. The importance of environmental benchmarks has been recognized early [2]. There is a demand for benchmarks on GHG emissions in the different phases of the building’s life cycle that serve as an orientation for designers [3].

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