There is a substantial gap between truly energy-efficient construction and what is currently being built. The problems range from lack of training to carelessness. But there are ways to cure the problems and bring best practices into widespread use.             

 The trend towards natural ventilation and low energy cooling systems is affecting the ways in which engineers design and operate heating systems in low energy buildings             

The new headquarters of the Commerzbank in Frankfurt - the tallest office building in Europe - has proved one thing conclusively: it is possible to build a vast high rise in the middle of a busy city and use passive techniques to control its internal environment

NatVent™ is a seven nation pan-European project which aims to reduce primary energy consumption (and consequently C02 emissions) in buildings by providing solutions to barriers which prevent the uptake of natural ventilation and low-energy cooling in countries with moderate and cold climates. It also aims to encourage and accelerate the use of natural ventilation and 'smart' controls as the main design option in new-designs and major refurbishments of office-type buildings.

The paper is structured in four sections. The introduction sets the notion of solar control as a fundamental issue in deciding the priorities of climate-responsive design for different building types and locations in Europe. The second section presents an overview of application contexts and means of solar control, and discusses design priorities and threshold conditions for different space functions and environmental design requirements.

The current recommended minimal ventilation level for the cold deck flat roof design is evaluated using an experimental roof. The work suggests that there may be a need for ventilation to be increased above the minimal level in instances where natural draught ventilation is low or where roofs are of complex plan. Results of this work are under consideration by the British Standards Institution as part of an overall review of flat roof design recommendations.