The project at Green Road Dalkey involved the construction of a two story dwelling cut into the existing rock embankment. This presented a challenging site with difficult ground and support conditions. A reinforced concrete basement box was elected as the chosen solution to house the lower level accommodation and this was constructed using single sided shutters up against the existing rock profile. The external face of the reinforced concrete walls were tanked using an active voltex bentonite water protection membrane and the added benefit of an internal passive drained cavity protection behind the new walls and over the new raft slab foundation. The excavation encountered was a particularly dense granite material and required careful coordination and sequencing of the works to allow for the safe excavation. The ground floor slab was constructed with a reinforced concrete precast solution and provided restraint to the top of the new walls and act as a bracing diaphragm. The upper level structure was a more traditional masonry block and steel beam construction with timber infill roof.

• Sustainable drainage solutions include rainwater harvesting and surface water discharge.
• An element of green roof is also provided to provide surface water attenuation and polishing filtration as a sustainability offering.
• The project was deservedly shortlisted as a ‘Grand Designs’ project of the year.