Improving energy performance: many small interventions or selective deep renovations?

Recent findings from a monitor containing around 1.5 million homes in the Dutch non-profit rented sector show that the energy improvement pace in the sector in the last years is too slow to meet the nationally agreed level in 2020. The findings also show that the improvement of the energy performance of the respective homes is mostly carried out in small steps: in many of the improved dwellings only one single measure is applied, and deep energy renovations are rare. Advocators of such renovations nevertheless believe that such improvements are the most appropriate way to substantially reducing energy consumption and argue that the developments and proliferation of energy renovation concepts is the best way forward. Others, however, do not see this as realistic and argue that reality forces us to proceed on the path of small interventions. This study sheds more light on this debate from the way in which housing providers conceive and implement their portfolio and asset management strategies. From these investment policies, it seeks explanations for the dominance of the small interventions and investigates the room for a more concentrated allocation of budget resources. To this end, housing providers with different energy investment policies are selected and interviewed. Results show that current practice leaves little room for deep renovations, but that a more mixed picture of small and deep interventions may be expected when zero-energy renovations grow out of their experimental status.