Design Solution · Sustainability
Design Solution · Dream about it
Planted terraces and roofs added during office retrofit.
Planted terraces and roofs are added during the upgrade to provide amenity, biodiversity and rainwater attenuation on a dense city site. Layering greenery onto a retained structure improves the building's environmental and social performance. It demonstrates ecological gain within a retrofit.
Adding planted terraces and roofs during a retrofit addresses three objectives at once — occupant amenity, biodiversity net gain, and rainwater attenuation — by leveraging the surface area that a retained frame makes available at low incremental structural cost compared with a new-build. The combination is increasingly required by planning policy in dense urban contexts, and a retrofit that already avoids demolition has a natural advantage in whole-project biodiversity accounting. The record is claimed without quantified performance data: there is no post-occupancy figure for attenuation volume, biodiversity unit uplift or thermal benefit, so the evidence base is thinner than the concept warrants. The specifier's practical considerations are loading — retained frames must have residual capacity verified for saturated substrate and live loads before specification proceeds — and maintenance accessibility, since inaccessible planted roofs deteriorate quickly and can negate the biodiversity benefit within a few years. Where those conditions are addressed upfront in the structural survey and the lease management framework, green terraces and roofs on a reused frame are a well-established and fundable component of a retrofit rather than an experimental one.
#green roof #biodiversity #amenity