Energy efficient glazed office buildings with double skin facades in Europe

Panel: Panel 7. Innovative buildings technologies

Authors:
Bo Eriksson, WSP Environmental, Sweden
Åke Blomsterberg, Energy and BuildingDesign, Lund University
and WSP Environmental, Sweden

Abstract

Many modern office buildings have highly glazed facades. Their energy efficiency and indoor climate are, however, being questioned. Therefore more and more of these buildings are being built with double skin facades, which can provide improvements:

A project BESTFACADE, with participants from Austria, Germany, Greece, Portugal, France and Sweden, was therefore funded by the European Commission (IEE) to actively promote well-performing concepts of double skin facades. Included were best practice guidelines, which included the determination of the energy use and thermal comfort by simulations for warm, mild and cold climates.

The main conclusion is that the choice of glazing properties such as glazing area, U-value (thermal transmittance) of the glazing and its profiles, g-value (the total solar energy transmittance) of the glazing and type of solar shading are crucial for the energy and indoor climate performance of an office. The choice of control strategies for ventilation of the cavity and operation of solar shading are crucial. The above choices are very dependant on the climate. Choices which are optimal in a cold climate, will not work very well in a warm climate, and vice versa. From an energy and indoor climate point of view a highly glazed office with a double skin façade is often preferred to a single skin