General Transformation Framework (GTF)
We started by identifying feasible interventions to improve the energy efficiency of walk-up apartment buildings. We based our GTF on the framework developed by Elkington to evaluate performance from a comprehensive perspective that takes into account environmental, social and financial aspects. We employed this triple bottom line – namely planet, people and profit – as the basic structure of the choice matrix for interventions from which design alternatives could be composed.
Planet, in the GTF, refers to a cluster of technical interventions that can be employed to improve the energy efficiency of the apartments. If the building skin is refurbished and air tightness provided, two problems will appear: the ventilation will not work properly and, because the noise from outside is reduced, tenants will experience more noise between apartments. According to preliminary research by housing associations, moisture and noise are the two main problems in relation to refurbishing the skin of the building. The indoor climate of the apartments must be treated as an integrated, healthy whole, with heat, fresh air and low noise levels. We therefore considered these three aspects as one intervention.
Profit in the GTF refers to a cluster of interventions that concern the housing associations’ investment (and in the end, the tenants’ rent). If it is possible to extend the building or enlarge the units by adding to the roof or the garden side, housing associations make more profit and can thus invest in the expensive adaptions of their housing stock.
People in the GTF refers to a cluster of sociocultural interventions related to the functional and cultural heritage qualities. By law, deep renovation may go ahead only if 70 per cent of the tenants agree to it. These blocks have a narrative value for their inhabitants. Of course, adaptions must sometimes be made to improve the quality of the building. Using a cultural and architectural value assessment, the different parts of the buildings were given a positive, indifferent or negative value. Preliminary research showed the importance of refurbishing and/or replacing the kitchen, bathroom and toilet areas. Spaces on the garden side and connected to a shallow balcony. This area is lacking service and storage space.