A highly architectural development, structurally akin to a commercial building in both magnitude and construction materials.
As with the neighbouring Lot 2, the steep contours which were cut into across the majority of this site provided challenges for the design and layout of this new two-storey architectural dwelling, with the natural ground profile being higher than the building roofline in places. This highly architectural development was structurally akin to a commercial building in both magnitude and construction materials, and incorporated a multitude of luxurious home features, as well as a lift, expansive outdoor decking (incl. spa deck), external courtyards, swimming pool, and an over-height garage/basement.
Due to the steep ground profile, and nature of the dwelling, each floor level cuts into the steep slope. Close collaboration with our in-house geotechnical engineers and surveyors was required to undertake feasibility planning and optimise the various retaining wall locations and design.
During the detailed design phase, the finished floor level of the first floor was raised to accommodate the client’s boat. Over-height reinforced concrete masonry (RCM) retaining walls (approximately 4.3m high) were designed at the ground floor level to accommodate this change by cleverly utilising the suspended concrete floor slab, and other concrete walls and keyed foundations.
Due to large openings to the front elevation of the building, there was a lack of bracing elements (walls) which could be utilised. This required the incorporation of strategic load paths, utilisiing additional walls (external walls, and the basement concrete masonry block shear walls) to resist lateral loads (EQ) by transferring these forces via the suspended concrete floor slab / diaphragm.
Shortly after engagement, FTL met with the main contractor and earthworks contractor, to collaboratively discuss the methodology and safety in design. An area where the project could be de-risked with improved safety and cost savings, along the southern and south-eastern boundaries was discussed. This area, adjacent to the neighbouring boundary required temporary shoring to prevent potential collapse of the cut face. FTL proposed a unique and innovative modification from the previously designed timber pole retaining wall, to a timber pole soldier pile wall, with an aesthetic timber facing, thus eliminating the need for temporary retention measures. This was implemented to great benefit to the project and client.
