Building up: Rotterdam relaxes rules to build new homes on top of 18.5 km2 of flat roofs

Rotterdam has taken several steps to simplify the process of building new homes on top of existing roofs. “With 18.5 km2 of flat roofs, the city offers potential for thousands of additional homes,” the city said in a press release. According to the municipality, the relaxed policies and extra support have already resulted in dozens of “top-up” homes being realized or in construction.

In the past 18 months, the city made it simpler and cheaper to top-up existing buildings by making it easier to deviate from car parking standards, lowering the minimum dwelling size, clarifying the aesthetic regulations for top-up homes, and including top-ups in the environmental vision for faster permits.

Rotterdam also abolished the compensation to the city for affordable housing. According to the city, scrapping that financial threshold will make top-ups more feasible for initiators like housing corporations, owners’ associations, and developers.

The new policy is already bearing fruit, the city said. For example, the housing corporation SOR completed 44 senior homes on Klapwiek, 7 apartments on Noordschans, and 12 homes on Meyburg. Larger developments are in the works in Katshoek and Westblake, where the top-ups will happen at the same time as sustainability upgrades to the existing buildings.

“We are making great strides with rooftop additions in Rotterdam,” said alderman Chantal Zeegers of climate, construction, and housing. “By relaxing policy, strengthening cooperation, and getting concrete projects off the ground, we are making our city smarter, more sustainable, and future-proof. Moreover, by abolishing the additional payment for the affordable segment, we are rolling out the red carpet for initiators.”