Harry Passivhaus: Coastal Living and Sustainable Design in Anglesea
Introducing Harry Passivhaus: nestled in the coastal town of Anglesea along Victoria’s Surf Coast, inspired by the timeless mid-century beach houses, this eco-friendly pad combines the laid-back charm of coastal living with cutting-edge sustainability. Embracing the philosophy of 'freedom is knowing you don't need more than just enough,' this two-bedroom and one studio home prioritises efficiency and performance while maintaining a modest footprint.
The house occupies a 120m2 area, with an additional 18m2 studio beneath it. This space serves as a work-from-home area, alongside a single garage and storage facility. Our primary objective was to minimise the building's footprint to preserve as much natural habitat on the property as possible. Despite the south-to-north slope of the block, we dedicated significant effort to ensure universal accessibility for all.
Passivhaus, Anglesea
Remaining true to Altereco's principles, we have incorporated a generous amount of natural timber throughout the home. While we have avoided exposing any glazing to the west, the home benefits from ample natural light through large glazed openings to the north and south. Although such extensive glazing ratios may not be ideal in a Passivhaus, living by the coastline allows us to capitalise on cross-flow ventilation during summer, significantly reducing our cooling loads.
At the heart of Altereco Design lies a commitment to resilience and longevity. We meticulously selected materials that are both affordable and locally sourced, while meeting the stringent BAL 29 requirements.
Harry Passivhaus stands as a testament to the harmonious blend of sustainable living, functional design, and environmental consciousness. With its modest footprint, efficient use of space, and incorporation of natural elements, this home exemplifies the notion that living well does not require excess. By embracing Passivhaus principles, we have created a dwelling that minimises energy consumption, maximises comfort and fosters a deep connection with the surrounding environment. Harry Passivhaus is not just a house; it represents a lifestyle choice that prioritises simplicity, resilience, and a profound appreciation for the beauty of it’s natural surroundings.
ARCHITECTURAL FEATURES & INSPIRATION
The design draws significant inspiration from the Lendlease Beachcomber home, which was constructed throughout Australia during the early 1960s. The house stands on stilts that is adorned with a long north facing veranda covered by a deep but low pitch roof. Whilst this suits a passive solar design, maximising good orientation is also applicable to a successful Passive House outcome.
The elevated dwelling is a modest 120m2 and contains what feels like a generous two bedroom home.
The under croft of the house incorporates the garage (40m2) and a studio (20m2), plus sufficient space for concealing all services and rainwater tanks.
MATERIAL CONSIDERATIONS
A simple palate externally was adopted, blackbutt timber windows & doors combined with vertical fibre cement boards that meet stringent bushfire requirements, whilst respectful to materials used in the construction of beach shacks that still remain through the township.
INFLUENCE OF SITE CONDITIONS
The corner allotment demonstrated immediate potential for a home that could appreciate good orientation to the north without loss of amenity. Removal of trees for the undeveloped site was considered, and four mature Messmate Stringybark adorn each corner of the site.
KEY ENVIRONMENTAL CONSDIERATIONS
The building foot print covers 25% of the site.
Performance
Passive House Low Energy
Heating demand: 17.6 kWh(m2a)
Cooling demand: 9 kWh/(m2a)
Airtightness: 0.58 ACH
Frequency of overheating: less than 25 days of the year when not using the AC (this is a theoretical figure, since there will be an AC in the house).
Frequency of excessive humidity: 0 days
Energy Rating: 7.4 stars
THERMAL ENVELOPE
Floors:
Ground Floor: Ground Floor: Slab, 100mm XPS [R3.2], Chipboard, Timber Floor Boards 240 deep joists @ 450 cts, [R6] Pink Batts, Chipboard, Timber Floor Boards.
Upper Floor: 240 deep joists @ 450 cts, [R6] Pink Batts, Chipboard, Timber Floor Boards
External walls:
Typical build-up: Typical build-up: cladding on ventilated cavity battens, ProClima vapour membrane, 40mm Steico Wood Fibre [R0.93], 150 studs & 600 cts, [R4] Earthwool Batts, Internal Air Barrier, 35m services cavity, 10mm plasterboard
Roof:
Typical build-up: steel roofing on ventilated cavity battens, ProClima vapour membrane, 40mm Steico Wood Fibre [R0.93], 90mm counter batten [R2.0], 240 Rafters @600 cts [ R6] Pink Batts, Internal Air Barrier, 35m services cavity, 10mm plasterboard
Doors & Windows:
Entry Door: IV68 double glazed
Sliding Doors: Lift n Slide double glazed
Windows: tilt turn triple glazed
ACTIVE SYSTEMS
Ground Floor: 2.5kW split system
Upper Floor: 3.5kW split system + ceiling fans in bedrooms, living
Ventilation:
MHRV: Zehnder Comfoair CA200, via FANTECH
Water:
Storage: 15,000 L water tanks
Collection Area: 144m²
Hot Water: Reclaim Heat Pump
Electricity:
Supply: two-phase 40 amp
Generation: 6.6kW (18 x 370W panels)
Storage: 13.5kWh battery (Powerwall)
Calculate Annual Consumption (PHPP): 6,800KWh
Data since installing Powerwall 17/02/23 to 09/10/23:
Backup History: 10 events, 8 hours total
Self Powered: 42% Solar, 45% Powerwall, 13% grid
Savings to date: $860
Solar Offset: 156% energy offset, 4,708 kWh solar, 3,008kWh home
BUSHFIRE RESILIENCE
Bushfire rating: BAL 29
Bushfire species timbers: Blackbutt
Windows & doors: 6mm toughened glass
Cladding: 9mm fibre cement cladding
Stainless steel mesh to all gaps and cavities