Investigating the business case for a zero-energy refurbishment of residential buildings by applying a pre-fabricated façade module

The ambition to renovate the post-war building stock to an energy-neutral quality is getting a lot of attention from social housing corporations and other institutional owners, financial organizations, and users. An effective renovation plan must significantly improve the current energy performance of a target building towards nearly zero-energy levels. A number of facade solutions have been developed in recent years to solve the problem of large-scale renovation of housing. In the Netherlands, several exemplary renovation projects have the ambition to achieve an energy-neutral objective. One such project is the 2ndSkin Façade refurbishment approach for post-war residential buildings.
Nevertheless, the market intake of such renovation is currently very slow, as housing associations are reluctant to invest the increased cost of a zero-energy refurbishment, despite the energy savings and ongoing benefits for the occupants.
Within the framework of the research project 2ndSkin, this paper presents a prefabricated and integrated façade module that provides the possibility to improve energy performance up to zero-energy use, while ensuring minimum disturbance for the occupants, both during and after renovation. Based on the proposed integrated refurbishment solution, the study presents a financial breakdown of this case-study concept - including options to lower the initial investment - in order to outline a more attractive business case. Firstly, three design variations, ranging from a standard external insulation upgrade to a zero-energy renovation, are compared, using a range of positive, average, and negative values for a series of financial and economic parameters. Subsequently, the financial performance of a zero-energy renovation investment is calculated for three different apartment properties with diverse market values, to determine the circumstances that can justify an energy renovation investment.
The analysis showed that, for properties with an intermediate to high market value, the investment can be attractive under current economic and market conditions, but this attractiveness drops significantly for lower-cost properties such as social housing. The study objective is to develop both the technical solution and the related business case to support the implementation of zero-energy refurbishment strategies into diverse real estate market tiers of the residential building stock.