How effective can we be?

Housing operators today require high efficiency ratios (GFA/BTA) while the demand for smaller apartments is increasing. This is an equation that is very difficult and in some cases impossible to achieve. The lab project was carried out with the aim of increasing the understanding and disseminating knowledge about the factors that affect the efficiency ratio BOA/BTA. 

The study was based on a stairwell with 3 apartments in a 12 m deep building. This typical stairwell was then compared with various alternative solutions to show the principle effects of the number of apartments per stairwell, external wall thickness, stairwell type and building depth.

The case studies used similar apartment sizes with functional room dimensions to ensure that the proposals provide good quality housing. To clarify the effect of different factors on occupancy rates, each parameter was presented separately.

The results clearly show that it is primarily the geometry that controls the degree of utilization. This means that it is the design of the zoning plan with building depth, in combination with the housing developers' wishes for apartment composition, that provides the conditions for the GFA/BTA ratio.