The East Lindfield Sub-transmission Switch project involved the rock excavation and concrete construction of a 4 level insitu building and roof on a steep site at Lindfield built adjacent to the existing 132kV covered switch yard. The new building houses the new 132kV circuit breakers along with the switch/control room and associated equipment. Unique features include 320mm thick concrete walls with a batten inprint to replicate the branches of trees, 12m high louvre panels, 400mm thick concrete roof and a 30m long steel bridge from the road to the control room. Architectural features of this project include: batten feature and Nawkaw staining to the insitu concrete walls, perforated aluminium powdercoated screening and extensive use of annodised aluminium louvres to the northern facade.