Here's the dirt on a rammed-earth renovation in Australia

Passive butterfly exterior
© EME Design via BDAV

Add heritage preservation, passive house design and a butterfly roof and it pushes a lot of buttons around here.

Victoria may be the smallest state in Australia, but there is a lot going on there, and its capital, Melbourne, was just dethroned after seven years as the world's most liveable city. There is a lot of design happening there too, and the BDAV or Building Designers Association Victoria has just announced its 2018 building design awards. There are a few interesting projects, including this commendation for "best environmentally sustainable design-residential"- I always seem to prefer the runners-up.

The Passive Butterfly by EME Design

Passive Butterfly dining room© EME Design via BDAV
There's lots to love in this runner-up, The Passive Butterfly from EME Design. It is "One of the first Australian homes with heritage planning restrictions to be renovated according to passive design principle goals"- a challenge, the mix of heritage and passive, that we have discussed a lot on TreeHugger. The architects write:

With part-Scandinavian heritage, the clients were passionate about efficient building design, and sought the highest standard of passive build they could achieve on the site – no mean feat when working with an existing heritage home. Exacting insulation measures and passive design principles, including a heat recovery system, ensure the building’s temperature fluctuates by just 1.5 degrees Celsius for 95 per cent of the year. This minimises the need for heating or cooling, improves air quality, and ensures the building outperforms many high-rated Nationwide House Energy Rating Scheme (NatHERS) rated homes.

Living room© EME Design via BDAV

The addition is also built out of one of our favourite materials: rammed earth, which is healthy, local, has fabulous thermal mass that works well in places where there is a diurnal swing in temperatures, and always looks terrific. Top that with a mid-century modern classic touch, a butterfly roof, and you push about 20 of my buttons at once. I love everything about it except that big black hole of a TV screen; they should trade that in for an LG Frame.

View to Kitchen © EME Design via BDAV

The asymmetrical butterfly roof form brings light to the rear living areas and heats the rammed earth internal walls – the backbone of the building’s thermal mass – in winter. The slope of the rear roofline also creates optimal growing conditions in a once sun-starved, south-facing backyard.

Passive Butterfly garden front© EME Design via BDAV

The heritage portion out front has new triple-glazed windows and a reworking of the garden reflecting a different heritage.

Indigenous plantings of gums and native habitat surrounding a feature billabong [a branch of a river forming a backwater or stagnant pool, made by water flowing from the main stream during a flood]. In practical terms, this small body of water supports overflow management, but it has also proved its magnetic appeal for neighbourhood kids, who regularly stop by in search of local wildlife. The indigenous landscaping choices have also broken the otherwise traditionally European-style plantings of the neighbouring gardens.

Passive Butterfly Exterior© EME Design via BDAV

So many ambitions in one project. Rammed earth plus passive plus heritage, it is hard to pull all of this off in one building.

CORE9 by Beaumont Concepts

Core9 exterior© Warren Reed and Leo Edwards

The winner in this category was CORE9 (It also won in Best Energy Efficient Design). BDAV sums it up:

This project was a standout for this category. Combining passive solar design, operational energy efficiency, and by using locally-sourced construction materials, this house achieves a very low carbon footprint on a very low budget. Adopting passive solar design principles to achieve a very high energy rating, it also embraced active systems to provide for all the energy and living requirements. The design responds to global initiatives in downsizing the physical and carbon footprint of homes, and exemplifies smart design for small living.

Core9 Interior© Warren Reed and Leo Edwards

There is a lot to love about this house. It's small (131m2 or 1400SF) and relatively affordable, and "achieves cost and resource efficiencies while embracing sustainable materials. Its light-filled northern orientation helps ensure the 9.1 star rated home is thermally comfortable year round."

living room© Warren Reed and Leo Edwards

CORE 9 includes extensive shading structures, thermal double-glazed windows, a photovoltaic system, low maintenance Weathertex zero carbon cladding, and sustainable Australian Silver top Ash hardwood to the exterior. The interior features upcycled, locally made furniture, recycled salvaged bricks, Eco Ply and Eco Blend concrete floors, LED lighting and locally manufactured low VOC paints and sealers.

core9 exterior© Warren Reed and Leo Edwards

But I must admit, the form of it put me off a bit, with the facade being designed around those solar panels and all the angles.

book coverGeorge Reynoldson and the Space/Time gang/Screen capture

It reminded me of the sloping walls in the solar design stuff from the seventies, the old "mass and glass" days, where the solar design drives everything. Sometimes you can have too much of a good thing.

Kallista By Maxa Design

Kallista evening© Chris Neylon Photography

Core9 also beat out the Kallista in Best Energy Efficient Design-Residential category. The designer writes that "when a client brief specifies a residence that is "soft, round and warm" it is stating the obvious to add they were looking for something a "bit different". They certainly got that, although "soft and warm" is a stretch.

Looking locally for inspiration, it was a charred fallen log on the home's bushland site in the Dandenong Ranges that inspired the eventual design's striking elliptical form. To support the client's desire for an accessible home (a home that accommodates all ages and all abilities) into retirement, Maxa opted for a compact single-level floorplan, a solution that marries curves and pragmatics.

Kallista End© Chris Neylon Photography

The house is built on stilts, which actually makes a great deal of sense in Passive House design- it seems easier to insulate the bottom of the house than it is to connect to a foundation.

The building projects out from the topography, and is supported by steel poles. These had to be anchored to the sub-soil rock to ensure stability in case of land slip - another very real danger given the site's pitch - but this solution meant the design team could protect the landscape.

Living room© Chris Neylon Photography

Employing Passive House design principles and construction methodologies including a 'magic box' heat recovery ventilation / hot water / heating and cooling unit, one of the first in Australia, resolved these issues, explains Maxa Design. Passive house methodologies carefully control insulation and air leakage, building orientation and shading, and recovery and filtration of indoor air to manage temperature and air quality. A certified passive house's performance can be measured precisely, with air quality and heat loss and gain data tracked over time.

Kallista Stairs© Chris Neylon Photography

It is a bit out there, this log on stilts, but "that this compact home blends into its environment, and is a stand-out design, is testament to the many constraints that have inspired this creative outcome."

award categoriesBDAV winners and commendations/Screen capture

There is a lot to learn from these two categories and three entries. The CORE9 clearly impressed the judges, perhaps because of its modesty of means and generosity of ends. The Kallista is out there in a tubular sort of way, a bit exotic. But my heart is with the Passive Butterfly; it seems the most comfortable and liveable and, with layers of complexity. It's the winner for me.

Here's the dirt on a rammed-earth renovation in Australia
Add heritage preservation, passive house design and a butterfly roof and it pushes a lot of buttons around here.

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