Conversation Seelhorst, Hanover

Seelhorst is a 1960s linear housing estate on the outskirts of Hanover. The residential ensemble developed by Gundlach comprises 130 apartments in 11 buildings and is characterised by a woodland-like atmosphere, which is currently disrupted by sealed parking areas and garage structures. The project aims to energetically modernise the existing buildings, create additional housing and at the same time preserve the green identity of the neighbourhood. Cost-efficient, climate-friendly measures secure long-term affordable housing and counteract gentrification. Implementation takes place in phases while the buildings remain occupied.

Densification is achieved through vertical extension. The existing settlement and building typology, generous green spaces and the characteristic tree stock are preserved. Previously unused attic spaces are dismantled and replaced by shallow-pitched, asymmetrical gable roofs. The extension integrates seamlessly into the existing building structure and, together with the refurbished façades, forms a coherent new architectural unit. The overall urban appearance is maintained.

The buildings are extended by one additional storey using fast, low-noise timber construction, creating 50 to 60 new apartments. Structural loads are transferred into the existing building framework, avoiding major interventions in the original structure. The new roof surfaces are largely covered with photovoltaic modules. A prefabricated balcony structure extends the living spaces and significantly improves the quality of the existing apartments. The façades are upgraded with biogenic cellulose blow-in insulation, while the balcony structures are designed as steel constructions.

Overall energy demand is significantly reduced. Space heating is provided by air-to-water heat pumps, while domestic hot water is supplied via electric instantaneous water heaters.

The new apartments introduce a diverse housing mix and respond to demographic change. In parallel, open spaces are upgraded and a future-oriented mobility concept is integrated. Existing trees are preserved, sealed surfaces are removed, and additional planting improves the microclimate, stormwater retention and biodiversity.