Alexandria Duplex
Located on a rear lane, behind four Victorian terraced houses, the 150 sq m site measures 15.7m wide x 9.6m deep. By the 1990’s, just 50 percent of Australian households contained only one or two people while in Sydney roughly one in three households contained just one adult- either a person living alone or a single parent. It seemed reasonable that the site provides for two terraced houses, each on 75 sq m, creating dwellings commensurate in scale with the narrow service lane.
The bulk of the accommodation is distributed along the lane frontage, with garages and living areas giving onto paved courtyards below, and bedrooms above. Privacy is maintained by the largely blank west elevation to the street, which also provides protection from the harsh low afternoon sun. This blank wall is relieved by a giant arch forming a common entrance for cars and pedestrians alike. Double height verandahs that mediate with the courtyards beyond are activated by stairs and filled with light from the clerestoreys inducing stack ventilation. The verandah roof, sloped at 45 degrees to follow the angle of the stairs, brings sunlight to the landscaped courtyards and reduces the apparent scale from the rear to single storey. The staircase, doglegging over the garage, lands on a free-form balcony cantilevered into the double-height space, providing access to bedrooms and a bathroom within the verandah roof.
The structure consists of 200mm-thick r c block party walls at 7.7m intervals, with steelwork between in an irregular arrangement that accommodates the complex variety of spaces. The upper steelwork of 125 × 75 rhs beams parallel to the party walls and 75 × 75 shs columns at 2.5m intervals forms small cellular spaces that are private in nature. These in turn rest on transfer floor beams running contrary to the roof beams which span between the party walls, creating larger more open spaces below. Front and back 200 pfc transfer beams are supported midway, creating 3.75m bays; the centre 300 pfc beam, carrying the greatest load, is supported off-centre with 4.3m and 3.2m spans on a circular freestanding 90mm diameter ‘rogue’ column that punctuates the living space, articulating the kitchen and circulation zones. The rear transfer beam forms an inclined steel truss, providing lateral stability. Suspended from this, a sliding frameless glass curtain wall creates an opening large enough to render the living area external as part of the landscaped courtyard.
Various materials in direct juxtaposition allow navigation around places of contrasting character, promoting a feeling of spaciousness. External stone floor tiles throughout and coarse external wall render enhance the perception of the living areas and bathrooms as part of the courtyard defined by quartz aggregate stack-bonded concrete blocks; American Walnut wall paneling creates a feeling of comfort and enclosure. Primary colours allow furniture and freestanding columns to detach themselves from their surroundings, creating an enhanced sense of separation and spaciousness.