Rather than building a brand new home, it can often make more sense to renovate an existing home and bring it in line with modern standards. This proved to be the case with the recently-completed Casa 31_4 Room House, which is based in Perth, Western Australia. The 1930s property was transformed into a passively-cooled home, complete with a modern extension that both adds space and contributes to its considerable charm.

The owners of Casa 31_4 Room House happen to both be experienced architects, and so Adrian Iredale and Caroline Di Costa naturally handled the design of the renovation themselves, in a process that took four years. The home's name derives from it being envisioned as four distinct living spaces.

Viewed from street-side, the two-story (and two-faced) Casa 31_4 Room House appears basically unchanged, in keeping with the local neighborhood. However, from the rear, a white extension looms large. This extension offers additional space, including a study and living room, while opening screens afford excellent views of the local area.

Casa 31_4 Room House also received significant energy-efficient upgrades, most notably in the form of a passive cooling system that's inspired by the Coolgardie Safe, a popular low-tech Australian refrigeration device invented to keep a miner's food and drink cool.

The Coolgardie Safe essentially operates in a similar fashion to a swamp cooler. As a water-soaked canvas bag comes into contact with the air, it evaporates the water in the bag, cooling the interior of the safe – and the contents inside – as a result.

In an email to Gizmag, Adrian Iredale explained that the passive cooling system of the Casa 31_4 Room House also operates much like a large evaporative system. Water is drip-fed by a reticulation system from overhead (the water is controlled by timer) onto fabric which doubles up as a privacy screen and sun shield.

The fabric then comes into contact with the prevailing breeze, and duly cools the interior space. The amount of water used is minimized as the fabric is only required to be partially damp.

During construction, removal of materials was shunned in favor of re-use where possible, and unwanted timber became furniture, decks, and door frames. Other practical energy-reducing measures include low-energy light fittings, a solar hot water system, roof-bound solar panels, and windows placed so as to maximize cross ventilation and winter heat gain. The existing chimney was also employed as part of a rainwater collection system.

Though generally tricky to get right, the clash of modern and traditional architectural design works very well indeed in the case of Casa 31_4 Rooms House. Thanks its appealing design, and its use of energy-efficient technology, the home will be briefly opened as a show house during the Australian Institute of Architects' 2014 Perth-based National Architecture Conference this May.

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