HDB Car Park Roof @ 18 Holland Drive – Singapore


To provide the intensive roof system to enable the establishment of a landscape roof on the roof of the car park.


VersiCell drainage modules were installed to provide a drainage cavity beneath a geotextile filter fabric layer and the planting soil above. VersiCell with high internal void and an open surface design is able to rapidly capture and transport excess water, preventing the green areas on the roof from becoming waterlogged. The drainage modules also provide a protection layer for the waterproofing membrane, a root-resistant fully adhered layer of Evalon PVC/EVA terpolymer membrane, prolonging its serviceable life.
Both intensive and extensive green roofs were installed side-by-side on this HDB car park roof top making it uniquely attractive. Residents in the vicinity enjoy a cool and aesthetically pleasing green roof instead of a hot exposed concrete roof.
The green roofs mitigate urban heat island effect, keep surrounding ambient temperature down and reduce transference of heat to the car park level immediately below. Additionally, they also offer other environmental benefits, by acting as a chemical, biological and particulate filter, filtering stormwater runoff at source, and helping to alleviate downstream problems associated with heavy downpours.