Outside the box: An energy-efficient addition

Issue 33 Words: Verity Campbell Photography: Loren Mitchell
Box Hill, Melbourne
  • Luke and Megan worked hard to preserve their double brick family home, while adapting it to suit their needs. They found that many builders and designers they spoke to didn’t see the value in retaining it, suggesting instead they knock it down and start again.
  • The water feature was an idea of Luke’s – a child-safe, but equally tranquil alternative to a pond, which also serves an ecological function.
  • The open plan addition is passively warmed with north-facing double glazing and insulated concrete slab. An efficient Morso S10 wood stove replaced the existing gas ducted heating system.
  • The new bathroom replaces what was the original kitchen, and is full of lovingly restored secondhand items.
  • The extension is sealed for comfort; the walls were built with larger studs to allow for R3.5 batts instead of the standard R2.5, and bigger rafters were used for the roof to fit R6 insulation batts. Furniture and fittings were reused wherever possible or sourced secondhand.

  • Glazing to the addition was carefully considered to maximise northern light while not compromising performance.

An energy-efficient addition to a charming double brick home in Melbourne’s east bucks the trend for all new.

Melbourne’s Box Hill has a diminishing number of eclectic, post-war homes, increasingly replaced by knock- down-rebuilds, and the newly renovated McCarthy family home almost followed the same path. The family – Luke and Megan, and their two children – loved their double-fronted brick home, but they found most building designers and construction companies they approached didn’t understand the attachment. “They often voiced the opinion that it’d be cheaper to bulldoze and rebuild,” says Luke, “and after many failed attempts to get build quotes, we almost gave up”.

Luckily the couple found a building designer up for the challenge. Simone Schenkel from Grüen Eco Design prides herself on her hands-on approach and willingness to go the extra mile for her projects. Her approach for this renovation and extension was driven by a philosophy that energy efficiency is achievable on any budget. “We had a very tight budget,” says Simone, “but we integrated the cost of energy efficiency into the design, rather than designing something and trying to make it sustainable at the end”.

With Simone on board, it took the team six months to find a builder willing to join this hands-on, ESD collective. But once they did, they set to work matching the construction details to the modest budget.

For the build, Luke decided to be on site as much as possible – an approach he highly recommends. “I took long service leave,” he says, “so I was on site when the work commenced. This meant any problems we encountered could be resolved quickly, and new opportunities could be realised. It also gives the builder a chance to learn your preferences so they can better make assumptions when you’re not there.”

The extension features a large open- plan kitchen, dining and lounge area. It opens out to a pergola and is built down the hill to immerse the room in garden views. An insulated concrete slab floor helps keep the home warm through winter, while in summer the pergola is covered with shadecloth to keep the heat out; eventually this will be replaced by the still immature deciduous vines.

Corrugated iron roof and timber cladding, exposed vertical beams and a concrete floor give the extension a sleek industrial flavour. Double-glazed windows, installed in the extension and retrofitted in the old part, fill the house with natural light. The uPVC window frames, fairly standard in Simone’s native Germany but relatively uncommon in Australia, were chosen for their insulative qualities, ease of maintenance and comparatively low-cost, “if you want timber frames for the same performance you pay much more, in this case it would have been over $10,000,” says Simone.

The floorboards, cabinets, bricks, kitchen benchtops, appliances, taps, fixtures and fittings in the house were either reused or sourced secondhand. “We made the budget work by saving money on recycled fittings and materials,” says Simone. “This meant we could spend more money on the shell of the house, and really good windows and insulation.”

A creative approach to materials delivered insulation gains without fiscal pain: the walls and roof are standard timber construction but, says Simone, “we built the new walls with larger studs to allow for R3.5 batts instead of the standard R2.5, and we used bigger rafters on the roof to fit R6 insulation batts”.

Outside the home received similar love and care. The family enlisted Ryan Young Designs to create a delightful and functional landscape with natives, exotics, vegetable gardens and water features to support the home’s cooling. “In the hotter months,” explains Luke, “we can open the smaller lower windows by the water feature to provide a little passive cooling in the evenings”.

The team’s comprehensive effort certainly paid off, bringing the home up to 8.1 Stars. The renewed house is comfortable year-round and saves its delighted owners on bills. “I’m proud of its high house energy star rating,” says Luke. “It has a higher rating than most new houses despite being a renovation and addition.”

The home has been recognised for its achievements too, shortlisted in the Premier’s Sustainability Awards 2015.


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Cover of Issue 33
You can read more about Outside the box: An energy-efficient addition in Issue 33 of Sanctuary magazine.

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Grüen Eco Design

Silkwood Constructions Pty Ltd

Ryan Young Design

Renovation and addition

Box Hill South, Victoria

$260,000 (incl. professional fees)

Land 765 sqm
House 164 sqm

8.1 Stars

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