A 1970s heritage-listed semi is re-engineered for contemporary family life. Keeping within the building foot-print, architect Conrad Johnston has carved extra space and forged stronger connections to landscape and place, while maintaining the integrity of the original structure and material language.
The house is one of a pair of heritage-listed semis, built in 1972 on a steep waterfront site looking across the Parramatta River towards Iron Cove to the south, and Birkenhead Point to the west.
Built at a 45 degree angle to the street, the semi zig-zags along the south boundary to side-step trees and sand-stone outcrops. Its three-storey concrete pillar and slab construction was infilled with floor-to-ceiling fixed glass. The superstructure was solid, but its timber cladding and windows were beyond repair. Inside, much of the original interior had been covered up and painted, concealing its materials and character. With no opening windows to the south and west façades, and an uninsulated flat roof, the building suffered extreme heat gain in summer and loss in winter. It relied on a commercial-scale air-conditioning whose mechanical plant occupied half the lower ground level.
Conrad is Director of Studio Johnston Architects. He is also a keen yachtsman, teaching his three children to sail, so the waterfront site was a key attraction. The house was not an immediate fit for them given its predominantly south-facing aspect, and had only two bedrooms, but the location generally, and the architectural challenge of reinvigorating such a robust structure was intriguing to Conrad. The other key attraction was the opportunity to create accommodation for grandparents on an under-utilised section of street-facing land.
The pair of semis were owned by the eminent Melbourne architect Sir Roy Grounds and his son Marr Grounds, an architect, university lecturer and sculptor. It is believed that Marr commissioned Stuart Whitelaw to design and oversee the construction of the semis (no. 6 and no. 8). Marr Grounds used the north-facing semi, while this south-facing semi was used by Roy Grounds as his Sydney pied-à-terre. After Grounds senior sold, the new owner added a brick double garage in 1983 and enclosed the first floor balcony. The semis are of local heritage significance for their hybrid Sydney School architecture and association with the Grounds family.
To turn the two-bedroom house into a four-bedroom sustainable home that could cater for multi-generational living. To open the building to private outdoor spaces. To improve environmental sustainability and performance. To redevelop the 1983-added garage incorporating a place for grandparents to live independently but connected to the family. To insert a plunge pool into the small harbour-facing garden.
Five key interventions to the site achieved a radical transformation.
Restoration of the superstructure included peeling out the perished interior linings, stripping back to the original concrete structures and replacing all fixed windows with new, high-performance timber-framed glass.
Connecting to landscape came through adding fixed and sliding sections to the new windows, but still within the original grid, opening the house to natural air and opening the kitchen and dining room to the cool south courtyard, forested with tree ferns. Adjoining the courtyard, and facing the waterfront, a small separate sitting room was raised up to level with the courtyard to form a seamless indoor-outdoor poolside/patio rumpus room, with a wet bar and bathroom behind.
More space was created within the building by converting the original air-conditioning plant on the lower round level into two bedrooms facing into the courtyard.
For in-law accommodation, the single level garage with its metal klip-lock roof were replaced by a new garage with a two-bedroom apartment above. While internally linked to the main house, this new building is its own entity in white-painted brick, with a deeply curved wall and a planted green-roof for camouflage.
Softening the geometry of the grid is achieved with built-in furniture such as the curved dining banquette along the party wall, that pushes circulation towards the outer window edge, increasing furnishable space.
Materials and colours are tuned to the original palette of painted brick, cedar windows and concrete. They are also chosen for sustainability. The rotted timber window frames are replaced with Western Red Cedar, while the rotten timber external cladding is heat-modified Radiata pine - all colour-matched to the original Mission brown. Interior linings were stripped and the concrete ceilings, pillars and floors all restored as new. Ceiling panels of carbon-positive Wood Wool and new-generation cork flooring bring a retro texture and warmth, and brilliant acoustic performance to the public spaces. In the kitchen and bedrooms, plywood joinery is finely de-tailed with brass. Bathrooms are tiled in a red Japanese finger mosaic, a nod to the original bathroom tiles found on site.
To improve thermal efficiency, the redesign includes significant new openings in the original glazing grid for air circulation, and upgrades all glass to high performance. All façades are upgraded with high R-value insulation and the lower-ground levels new concrete slab includes hydronic heating. The new self-contained studio has a green roof, high-performance glass and strategically located windows for natural light and air flow.
SUSTAINABLE FEATURES
R-value insulation to all façades
High-performance glass
New & expanded window openings to increase ventilation
Hydronic floor heating
Removal of air-conditioning system
Green roof on new apartment above garage
Sustainable interior linings: plantation pine, wood-wool ceilings, cork flooring
