Recently the govenment has decided to lay priority on quality rather than quantity in its housing policies. The aim is to supply comfortable energy saving houses and protect the well-balanced natural environments from pollution. This means that more and more houses which are superior to traditional houses in thermal insulating and air-tightening will be built all over the country. In such houses vapor barrier is usually formed on the interior surface of the insulated wall. And the vapor barrier is also useful for air-tightening. But it is very difficult to form seamless vapor barrier because of pipes and cables for water, gas, electricity and sewage which impede air-tightness. So we devised a prefabricated insulation panel with the vapor barrier in it. And then we constructed an experimental house in which we could ensure the thermal insulationand air-tightness, by applying our newly-devised method to the wooden frame. In this paper we consider the procedure of designing the panels and constructing the experimental house, comparing with several outside insulated (experimental) houses where thevapor barrier and insulation were formed at the building site.
