Calculating life cycle costs in the early design phase to encourage energy efficient and sustainable buildings

Panel: 5. Saving energy in buildings: The time to act is now

This is a peer-reviewed paper.

Authors:
Gerhard Hofer, e7 Energie Markt Analyse GmbH, Austria
Bernhard Herzog, Wipplingerstraße 12 -2, Austria
Margot Grim, Theresianumgasse 7/1/8, Austria
Klemens Leutgöb, Theresianumgasse 7/1/8, Austria

Abstract

Consideration of Life Cycle Costs (LCC) during the early planning phases of buildings is insufficient at the moment. The reasons for this are that on the one hand, the focus of clients for whom a building is being built most often remains on the initial investment costs. On the other hand, available software tools are complex and the data needed to use them properly is vague during the early design phase – the phase where cost minimising can be most efficient. Other tools can be used in the early design phase but don’t have a cost database to calculate LCC without first cost estimations.

The goal of the project that was funded Centre for Innovation and Technology in Vienna was to develop a method of calculating LCC in order to provide clients for whom a building is built with a well-founded basis for decision making in order to:

• optimize requirements during programming and setting up the brief, and

• select the best systems in preliminary designs and drafts during the planning phases.

The new method can illustrate the characteristic values of space efficiency, energy efficiency, and cost efficiency of the investment and operation. This was developed through an assessment of the design process and by analysing the main building elements in the decision making process that have a significant effect to the investment and running costs of a building. Furthermore, costs for several categories (investment, maintenance etc.) were calculated for these building elements an inserted into a database. Main goal was also to include the dependency between energy efficiency measures, investments and running costs, turning special attention to energy costs.

Through the integration of this method into a software-based tool with an acceptable input of time and effort, it should be possible to make reliable statements on prospective investment and operating costs of the building and thereby accelerate the realization of energy efficient concepts.