Tests carried out during the sixties and seventies showed that there was a correlation between lung cancer and the existence of radon gas in mines and that there was radon gas in homes built of aerated concrete based on slate. This led to political activity with regulations for limits on emanation in new, re-built and existing buildings. Provisions were also made for grants to help house owners finance the improvements specified.< In the new bye-laws, SBN 80, gamma radiation is not to exceed 50 mu.R/h, the radon content is not to exceed an annual mean of 70 Bq/cu.m.

Describes some of the problems encountered when the full-scale wind pressure measuring system was set up in an experimental building at the University of Hong Kong. Discusses effects such as excessive damping caused by the air trapped in the pressure- balancing tubings, and the interference between transducers. Describes modifications of the measuring system to overcome these problems.

Reports study of the energy consumption and ventilation requirements of typical existing public schools in New York. Electricity and fuel-oil consumption data from May 1970 to April 1973 from 19 schools were analysed.

Notes that many existing dwellings are inadequately insulated and in need of caulking and weatherstripping. Gives criteria for the selection of retrofit materials which are eligible for the Department of Energy Weatherization Assistance Program. Materials discussed are insulation, storm windows and doors, caulks and sealants, weatherstripping, vapour barriers, clock thermostats and replacement windows. Discusses the literature on retrofitting. Describes the different caulks and sealants available. Outlines precautions to be taken when applying different retrofit materials.

Calculations show that natural ventilation exploiting wind and specific gravity differences may reduce the need for ventilation heat. This is not done as usual by ventilation through open doors and windows but through fine porous air-permeable outside walls. The optimum thickness of the heat insulation layer is defined, giving maximum saving of total heating and ventilation energy.

Reports study of wind and rain over fifteen years and gives table of results. Reports measurements of wind pressure and driving rain on buildings. Discusses laboratory measurements of the tightness of facade elements under pressures of up to 50 Pa. and with temperature differences of -40 to +30 deg.C. across the facade. Describes pressurization of buildings and gives results of measurements in test dwellings. Discusses movement of joints in buildings and describes measurement of this movement.< Discusses permeability of both flat and sloping roofs.

Reports measurements of radon daughters in air. The daughters were collected on filters for different lengths of time. A silicon semiconductor detector and the etch foil technique were used to measure the alpha particles from the radon daughters. Finds that alpha particle concentrations in living rooms have the same variation with time as outdoors.

Reviews the ventilation requirements for residential buildings and the recently discovered contaminants of indoor air which will have an influence on the required ventilation rates. Describes methods of measuring air leakage and the rate of air infiltration. Cites work aimed at finding the correlation between air leakage and air infiltration. Outlines the role of heat recovery devices and recommends areas of further research. An appendix reports on a Canadian Mortgage and Housing Association seminar "Controlled ventilation with exhaust air heat recovery for Canadian housing".

Air quality inside buildings depends on the contamination of outside air as well as on the air pollution inside the room. The human being contaminates the air through carbon dioxide, odours, vapours and particulates. The most important sources of pollution are tobacco smoke, consumer materials (organic solvents), building materials and furniture fittings (formaldehyde) and the use of gas for cooking and heating (nitrogen oxides, carbon monoxide).< Discusses these pollutants and reported levels of pollution in Swiss buildings. Discusses methods of removing pollutants from the air.