As part of a project financed by the National Foundation for Energy Research (NEFF), the Building Services Section at the EMPA examined the thermal behaviour of one building, with zero energy demands, located in a low energy housing estate in Waedenswil on the border of the lake of Zuerich. The estate was initiated by Dr. R. Kriesi who also made the energy concept. The architect was R. Fraefel and the estate was financed also by the government of Zuerich. The measures taken in order to reach a minimal heating demand in the chosen zero energy test house were as following:

The aim of the study was to design and build a small house with 50% lower heating energy consumption than in typical existing Finnish small houses. Energy saving is based on three technologies: super insulation, airtight construction and ventilation heat recovery. The first monitoring results show the heating energy consumption of the house to be less than half of the measured consumption of typical small houses located in the same area. Also, the results show the air quality to be good.

The computer model SIN-BIP is built as a combined model that can calculate energy consumption, price and environmental load for a building to get an energy efficient building. The program has a database with information of price, thermal conductivity, moisture conductivity, energy content and CO2-emission for materials. On the basis of this information can the program calculate for each construction, the U-value, the moisture resistance (and if there is condensation), the price, the energy used for producing the material and the environmental load from CO2-emission at the production.

The Majrovagen project is the result of a design competition, held by the City of Stockholm and the Swedish Council for Building Research in 1990. The competition is a part of the efforts made by the City to promote efficient energy use and healthy buildings. Efficient energy use will help reduce disruption to the environment, the need for new, expensive energy plants, and, not least, the energy costs of the inhabitants of Stockholm. Three different projects with mu It if amity houses of about 60 apartments each were chosen by a Jury to be built in the same area during 1993.

The large number of innovative energy concepts which have been elaborated today to the stage of practicability open up new opportunities for contemporary architectural design. Energy concepts which pursue the aim of making optimum use of every available energy potential make the building itself an essential component of the basic energy logistics.

Passivehouses in Europe with a specific energyrequirement of less than 30kWh/(m2a) total for heating, tap warm water, ventilation and household electricity have been realized in Darmstadt, FRG. Four families live in the dwellings with extreme thermal insulation, heat recovery and optimized use of passive solar energy. The measurement program includes more than 200 sensors; temperatures, comfort, energy flows, air flows and indoor air quality are monitored. With dynamic simulation comprising about 2000 cases of alternative design of the building components the project was optimized.

Two identical apartment buildings were built, one in Germany, and one in Sweden, in 1986. The idea was to create energy efficient housing at a low cost, using Swedish building technology and German heating and ventilation technology. The Swedish building code, which is more stringent in terms of energy conservation than the German one, was applied in both countries. The paper examines the performance of the buildings.

Intermittent heating patterns, characteristic of Israel and other countries with a mild winter enable energy · conservation at the expense of very high peak energy consumption; · very low levels of thermal comfort; and surface condensation and mould growth problems. The paper summarizes a research project which included analysis of total daily energy consumption, partial energy during evening (peak) hours, weighted cost of total energy, improved thermal comfort, internal surface temperatures -of the external envelope, and surface temperatures of partitions.