The background for this study is that there were a great amount of buildings constructed in Sweden in the years 1965-1975 in a program designed to create one million apartments in a time-period of ten years. These buildings are now, somewhat forty years later in most cases in very poor condition and the need for renovation is great and urgent. This has become a growing problem and more and more voices are being heard pointing towards the vast and extremely expensive task of renovating these buildings. Lately, it has also been more and more important for buildings to be energy-efficient and sustainable environment friendly.
In recent years there has been an atempt to solve these problems by renovating such buildings but at the same time making them very energy-efficient. This is in some cases being done by isolating the shell of the building and changing the ventilation-system and so forth. Brogården in Alingsås is the first project to do so and it was finished in February 2009.
Our aim has been to simulate actions like the ones in Brogården on two houses from that period of time. By various calculations and conclusions we´ve shown what the result would be if we isolated the shell, replaced the windows with super-isolated windows and changed the ventilation-system.
To calculate the energy use we´ve been using a energy calculation program called VIP+ where we have built up the two houses artificially and then simulated the actions mentioned above to decide what the result would be. We have also translated the reduced energy use into a yearly cost to show what the total profit in money would be.
The result shows that if the decision would be to go through with this project on these two houses in Västerås they would gain a total of 53 % regarding the energy use in those two houses. This means that the total energy-use have been reduced from 128 kwh/m2 to 60 kwh/m2.
2009. , 49 p.