This research investigates whether top-floor apartments in post-war buildings command a price premium, and whether this changes when an additional floor is added. The study distinguishes perception from evidence, using detailed transaction data from Amsterdam. Understanding this dynamic is crucial for Owner’s Assiations (VvE’s), lenders and developers considering Rooftop development.

1. Rooftop development offer substantial potential - Post-war buildings (1945–1970) with flat roofs and four storeys form a significant part of Amsterdam’s housing stock and provide strong structural and architectural conditions for adding new units. Rooftop development could sustainably decrease the city’s housing shortage by approximately 9%.
2. The fear of losing top-floor “exclusivity” limits full approval from homeowners associations - Rooftop development is often met with resistance from top-floor owners, who fear that the loss of exclusivity will reduce their property value. However, there is little empirical evidence that this perceived exclusivity is reflected in market pricing.
3. Adding a fifth floor does not reduce existing top-floor values - Analysis of 1,062 apartment transactions in post-was buildings (2022–2025) shows that price per square metre generally decreases with each additional floor level. The relationship between floor level and price is consistent across both four- and five-storey buildings, indicating, top-floor “exclusivity” is not a price determining factor.
4. Accessibility, not exclusivity, shapes floor-level pricing - Since post-war buildings are typically constructed without lifts, differences in market value between floors are primarily driven by physical accessibility. Higher floors are priced lower because the additional effort to reach them often outweighs their advantages for many buyers.
5. Lenders view rooftop development positively - All interviewed lenders assess vertical extensions positively as a contribution to sustainability and densification efforts. For most lenders improved energy performance plays a key role in determining financing conditions.
6. Fragmented ownership is viewed as a critical barrier - Lenders evaluate rooftop development projects similarly to conventional redevelopment, with particular attention to structural feasibility, VvE approval and sustainability. However, only some lenders consider rooftop development feasible in cases of fragmented ownership, limiting the scalability of such projects.