Energy Consumption in Office Buildings

Investigator

Lukas Weber

Collaborators

Jochen Ganz, Ivan Keller, Robert Kroeni, Dr. Hans-Juerg Leibundgut, Urs-Peter Menti, Winfried Seidinger, Daniel Vuille and Hansjuerg Zimmerli (Amstein + Walthert AG); Edelgard Gruber and Katrin Ostertag (Fraunhofer Institut fuer Systemtechnik und Innovationsforschung Karlsruhe (ISI)); Prof. Dr. Daniel Spreng (ETH Zuerich)

Time Frame

August 1996–May 1999

Financial support

Projekt- und Studienfonds der Elektrizitaetswirtschaft (PSEL), Swiss Federal Office of Energy (BFE), Union of Swiss Utilities (VSE), Electric Utility of the City of Zurich (EWZ), Various Swiss local energy administrations

Budget

500 kCHF

Synopsis

The development of electricity consumption and energy-relevant decision-making within the period 1986–1996 was empirically studied in a Swiss nation-wide survey of office buildings.

Contents

Project Description
Publications and Presentations

last update: September 19 2000


 

Project Description

The development of electricity consumption 1986—1996 in 100 Swiss office buildings was empirically analysed in order to determine trends in consumption and to characterise energy-relevant decsion-making. The results empirically build on electricity bills, energy audits and interviews with technical staff and managers in firms. The aims of the study were:

The average electric energy index amounted to 300 MJ/m2a. It varied considerably according to the equipment installed in the building, e. g. air conditioned buildings consumed three times as much electricity as buildings without electrically-powered ventilation. From 1986 to 1996, the electric energy index decreased by one percent per year. Electricity was mainly consumed by central computing, ventilation, air conditioning and lighting, which took up altogether about 80 percent of the electricity consumption. The share of office equipment was only 10 percent.

The average thermal energy index amounted to 390 MJ/m2a. In new buildings it has decreased by 30 percent over the last twenty years.

The data collected in the study show that, although the management tended to overestimate energy costs by a factor of three, energy efficiency was taken into consideration in less than a quarter of all decisions related to a change in technical infrastructure or maintenance. Such decisions I call energy-relevant decisions. Moreover, only one seventh of the total reduction in electricity consumption resulted from a decision expressly intended to save energy. Most energy savings were a positive side-effect of core business-related activities. The factor found to have the most impact was an increase in computing.

The majority of energy-relevant decisions were about investments. The nominal decision-maker was the management, but in practice decisions were found to be mostly taken by specialists inside the firm, e. g. the maintenance staff. Conservation measures that require an extra investment are unlikely to be taken because of their low priority compared to investments in the core business. Successful conservation measures were mostly initiated, decided and realised by a single person fairly low down in the hierarchy.

 

Publications and Presentations

Publications

Reports and Miscelaneous

Presentations