BRIEF & DESIGN
The essence of the Owners’ brief was achieving a design that respected and responded to the site without making a pronounced statement or impact on its visual amenity from adjacent and distant vantage points.
While uncomplicated in form the house offers a variety of spaces, experiences and views. Expansive sea, farmland and bush perspectives can be enjoyed from within the context of a bush retreat.
The owners had a particular focus on the visual analysis of the site, requesting a house that blends very well with its environment through careful colour selection and a form sympathetic to the contours and surrounding vegetation, presenting a variety of surface planes across the five pavilions and avoiding extended straight lines. The design expressly avoids benching the site and celebrates its gradient through the graduation of levels from one pavilion to the next, avoiding a flat, monolithic form.
The house is a Contemporary ‘response to place’. It is shaped by orientation, views, prevailing breezes, the slope of the site and street access. Materials are very low maintenance and combustibility.
A height limit of 7.5m is a condition of the local planning policy. The house is single storey but multilevel, stepping across the slope, which minimises earthworks and allows higher ceiling levels in the living area to be achieved whilst keeping within the height limit.
The house is as energy efficient as possible maximising the passive solar benefits offered by the site exceeding the minimum 6-star requirement.
A warm & inviting, low-energy, low maintenance, robust family home capturing the vegetated coastal environment with a holiday feel. The home embodies casual elegance with a sense of openness and connectivity with the surrounding natural landscape and coastal environment, maximising access to sea and inland views.
The Entry and Living areas are defined by the extensive use of glass, where appropriate considering energy efficiency, and limited Stabilised Rammed Earth (SRE) internal walls for thermal mass and softness of colour and texture.
Environmentally Sustainable Design (ESD) elements;
- Performance glazing where glazing is extensive, i.e. high glass to floor area ratio, and considered essential by the AccuRate assessment
- Extensive winter sun penetration and cross ventilation
- Latest technology and low energy lighting
- Ceiling sweep fans in all bedrooms
- Instantaneous gas HWS
- All building materials are corrosion resistant, non-combustible and applicable for the coastal and high bushfire prone area
- Fujiclean wastewater aerobic treatment unit, ATU. Waste water is reticulated sub-surface to landscaping.
Passive solar design principles have been employed to maximise winter solar gain, minimise summer solar gain, eg Long E-W axis, majority of glazing on north elevation, optimum eaves on north façade, decks on E & W elevations to protect glazing from early morning and late afternoon sun, minimum south facing glazing
The two upper level pavilions are designed with a ‘hypar’ roof. The name hypar is derived from hyperbolic paraboloid which in simple terms is a skillion roof with a twist. The pitch at the west end of the roof is five degrees; increasing constantly to 12 degrees at the east end. The low southern edge is horizontal; the high northern edge is raking. The purpose of the hypar is two fold; firstly to close down the west facing aperture formed by the roof and the ground, reducing exposure to hot afternoon sun, and increasing the east facing aperture to maximise the expansive easterly view and secondly to break the horizontal lines of the pavilions.
Although the hypar form comprises straight rafters and roof battens a changing pitch induces an interesting curved roof surface akin to the double curve of a drying leaf. The effect is a subtle softening of the pavilion forms.
The client is a very successful Project Manager, well known in the WA construction industry, and came to the project well informed about both the brief and the design and construction process.
The owners selected Springate Constructions after careful market research and were very keen to engage with a cohesive and creative builder/architect team with close attention to detail, requiring limited oversight from the owners themselves – particularly important given the distance from the owners’ Perth residence to the site.
The project was procured via a ‘Design and Construct’ (D&C) contract with Springate Constructions the Contractor. Naked Architecture was engaged by Springate Construction and provided architectural design and documentation services including steel fabrication shopdrawings and limited services during construction.
The client elected the D&C methodology for its strong commitment to a team effort. Owner, builder and designer worked together seamlessly to develop the brief, create the design, monitor the cost and construct the building with maximum cooperation and without conflict. The project was delivered to a high standard of finish, on time and with minimum fuss. Progress was reported with regular photographs and decisions made via teleconferences and a few site visits. To this end the project worked extremely well.
BUSHFIRE MITIGATION MEASURES
Due to an extreme ‘Bushfire Attack Level – Flame Zone’ (BAL FZ) rating the existing vegetation was cleared of dead trees, braches and undergrowth and thinned. A 6m zone around the house was cleared and a further 25m zone was ‘parkland cleared’ to reduce the bushfire risk.
An extensive bushfire suppression system was also constructed comprising the following components;
- an arc of purpose designed sprinklers located atop 2m standpipes approximately 25m down slope from the house from the NE to the SW
- window drenchers located on all north, east and south facing windows
- three fire fighting hose reels located around the house connected to a dedicated pump
- dedicated fire fighting diesel pump with automatic, remote and manual start functions. Heat sensors located in the bush detect an approaching fire and automatically start the pump which is connected to the sprinklers and drenchers
- 150,000 L water tank incorporating rainwater harvesting potential
- A foam induction system, that reduces surface tension of water, is also incorporated in the fire pump to further enhance the efficacy of the drenchers and sprinklers
A further safety measure is a below-ground Wildfire Safety Bunker which provides a safe haven for up to six people, the first privately owned safety bunker in WA.
Construction cost; including extensive site works, eg driveway, water storage tank, sewerage treatment system, fire suppression system, earthworks, retaining walls, landscaping; $1.7m
Started September 2011, completed December 2012
Photographs courtesy of Mark Cooper Images