Sustainable House Day, Gosnells, Western Australia

“PELOHA” -  a bermed Solar Hemi-cycle House

Architect: Architect Gérard Siero

Engineer: Scott Smalley Partnership – Bill Smalley

Builder Owner-Builder

The architecture responds to local environment and climate embodying thoughtful, well-made construction with quality materials and technologies, enhancing liveability and reducing life-cycle costs of the house while extending building life and reducing maintenance. The design is richly layered with functional and design patterns [A Pattern Language, (Alexander, Ishikawa, Silverstein, et al, New York, Oxford University Press.)]
Together, house and landscape define a circular outdoor room, viewable from all rooms, fringed with gardens (high maintenance close by), surrounded by trees and shrubs to soften climatic extremes, provide seasonal shade and filter air.  Lawn water use is minimal.  Indigenous plants connect to local riverine ecology.

Site
Easterly views to nearby Darling Scarp provide a semi-rural atmosphere and access to local catabatic breezes to aid night cooling to this flat, sandy block above the floodplain of the Canning River.
The north facing house is set back, allowing space for a landscaped “borrow pit” (to be a wetland) for soil for the surrounding earth berms. A Shire requirement to raise the pad 600 mm necessitated importing much more earth.

Brief / Programme

A comfortable, peaceful house for one plus guests:

•       Passive solar climate response
•       Energy efficient
•       Low maintenance
•       Integrated with landscape
•       Private and quiet
•       Age gracefully (remain in own home)
•       Low environmental impact
•       Low ecological footprint
•       Durable materials

Features

The design comprises (from outside in):

•       Carport, Shed and Entry Porch
•       Entry (Airlock), Bay Window, Bathroom, Bedroom,
•       Sitting, Dining, Kitchen, Laundry/Pantry
•       Guest Room/Study, En-suite
•       Store/Shed
•       Meadow and tree circle; berms with indigenous planting

Climate Response achieved by:

•       Solar Hemicycle (Plan Form)
•      Suntrap: captures winter warmth
•      Sun tracks occupants through the day
•      Curved wings provide morning and evening shade from low summer sun
•      Deep shade
•       Solar balanced eaves
•      Winter sun in
•      Summer sun out
•      Equinox cut off
•       Thermal mass (with earth couple)
•      Earth Berms (shaded by plants)
•      Masonry (Thick Walls, insulated & vented)
•      Concrete floor, polished
•       Earth couple stabilises temperatures of surfaces walls and floors.
•       Microclimate amelioration and late season shade by landscape: trees and shrubs.
•       Earth pipes  = natural air-cooling.
•       Built form manages local breezes.
•       Airlock Entry – less gain/loss when entering
•       Low-e glass manages radiant heat in and out.
•       Low and high vents for cross ventilation, and night purging, augmented by earth pipes
•       Cedar louvres for low shade at ends
•       Natural light: healthy, cheerful, functional
•       Solar Hot Water – split system = no ugly tank.
•       Provision for micro-generation of electricity (photo-voltaics & wind) on Carport roof.
•       Cavity walls vented and insulated (piers help provide a Tapestry of Light and Dark inside).

Planning and Design

•       Privacy zoning – Intimacy Gradient
•      Peg’s personal space at West end – beyond Entry A Room of One’s Own.
•      Common Areas At The Heart, Sitting, Dining, Kitchen.

Plan = curved Long Thin House with efficient circulation along window wall, with Flow Through Rooms / functional use areas in passive spaces.

•      Guest Room/Study at East end – beyond Laundry/Pantry.
•       Acoustics: Quiet - minimal neighbourhood noise deflected by berms and built-form.
•       Universal access design for graceful aging in one’s own home: wide doors, hobless showers, lever taps, handrails, easy-care, durable finishes, minimal steps.
•       Functional Kitchen features a Sunny Counter of recycled timbers, Ecoply doors and low emissions carcases, well lit bench.
•       Laundry outlook to Garden.
•       Bay Window Box – Sunny Place / Alcoves / Window Place – cushions: sit, read and relax.
•       Structural steel glazed wall supports roof = dual function = savings on windows.
•       Stone-faced piers delineate the 3 living zones, providing transitions between them.
•       Structure Follows Social Space.
•       Storage over  + drama of height variety
•       Bus-way for electrical lighting and wiring.
•       Colours – relate to local nature.

Environment

•       Planting – indigenous plant species –support local biodiversity, bird attracting (Lulfitz New Image for West Australian Plants).
•       Trees for shade and filtering of air and noise.
•       Artificial wetland – a local landform type.
•       Design reduces environmental impact of materials, outputs and energy use, compared to normal house.
•       Pre-plumbed for future grey water treatment.
•       No toxic pre-treatments used.
•       Continuous concrete forms part of termite management; Access under deck facilitates inspection.  Penetrations collared.

Materials and Equipment:

•       Solar hot water system – Sola-Kleen, copper.
•       Sustainable (plantation) timbers: Ecoply ceilings, treated LVL rafters, Cypress decking.
•       Recycled timbers: counters and deck.
•       Cedar doors and windows, ss hardware.
•       Plasterboard lined framed walls for services in feature colours.
•       LED lights – low voltage, low consumption, long lasting.
•       Steel structural frame with inorganic zinc silicate (cold galvanising) – and antirust paint.
•       Local Concrete, polished surface.
•       Bricks: Smooth Cream - Midland Brick.
•       High density polystyrene insulation: Foam Sales – Simon Barnett.
•       Ecoplywood cabinets specified. >