Blue Mountains House | Christopher Polly Architect

A new off-grid house makes geometric allusions to the clients’ love of the abstract formal qualities of modernist houses by Myron Goldfinger and Charles Gwathmey. Based on a 4m x 3.8m structural grid, the design pin-wheels a series of private and public rooms around a central courtyard to provide a modest internal floor area of 100 sqm with a low environmental footprint of only 129 sqm on the site. Pop-up roof projections at each corner amplify the pin-wheel to offer expanded volumes and varying connections to tree canopies and sky views.

Aside from requisite living, dining, kitchen, and bathroom spaces, it accommodates a dedicated office, a covered entry terrace for outdoor dining, 2 bedrooms with ensuite bathrooms, and a 3rd room which is flexibly adapted from a second living space to a guest bedroom. The interior completely opens to the central courtyard inlaid with a circular brick pattern, to allow spatial interplay and a variety of slight lines through the house.

It incorporates a number of robust and durable materials to meet the design performance required of a BAL FZ high bushfire attack level, inclusive of a fireproof concrete base, low carbon fibre-cement panels, pre-finished metal cladding, and fire-rated thermally efficient double glazing. External horizontally-sliding metal mesh screens and vertically-retractable motorised screens provide fire barriers and enable moderation of solar access when required, allowing its entire envelope to be fully ‘shut down’ when unoccupied. It proposes several off-grid measures including a solar system for power generation, 20,000 litres of underground water storage, under-floor heating, a small wood fire, and a heat recovery system to duct warm fresh air heated by exhaust air as needed.