Retrofitting halves school's heating bill.

The Jandel school in southern Sweden was thoroughly retrofitted in 1994-95. Both lighting and ventilation systems have been designed for high energy efficiency. New windows with excellent insulating performance have been installed. A before and after comparison shows that the energy required for heating has been reduced from about 210 k Wh/m2 to about 94 k Whlm2 a year, i.e. a reduction of about 55%. Electricity for building services systems has decreased by about 20%, despite the fact that considerably more computers are used in the school today than prior to rebuilding.