Written by Vicki Holder
Turning heritage villas into modern, energy efficient homes is difficult and expensive, says architect Lindley Naismith, partner in Scarlet Architects. The practice specialises in alterations to character homes in Auckland’s older central suburbs, and Lindley frequently encounters the same old dilemma.
“Their design and construction no longer meet the needs of comparatively wealthy modern city families.”
As much as we love the gracious heritage character of original villas, bungalows and cottages and the Council has strict rules around preserving them, they’ve been neglected through the years. “Basically they’re now just a pile of old sticks.”
Lindley’s clients typically come to her to make their home function better for family life. “People are looking for a higher level of comfort especially in kitchens and bathrooms around a lean-to structure at the back that haven’t been touched for 100 years. At the same time, we talk about making the house warmer.”
She explains, sustainability is all about designing to reduce the overall impact – during and after construction - to meet present needs without compromising the ability of future generations to meet their needs. So, when you’re talking sustainability, says Lindley, the first decision when upgrading is to ask if the existing building should stay.
The process starts with orientation. Lindley looks at where the sun comes from. “The issue with older suburbs, houses are close together and oriented to the street, not the sun.
“And how far do we go with the existing building? There’s a lot of cost involved in upgrading 100 year old buildings to meet contemporary standards. Start taking wall linings off and you find you don’t have much in terms of structure.” A common scenario is to add a substantial new floor area at the back where “a crappy lean-to has been”.
“We design that to [energy efficient] contemporary standards and do the best we can with old buildings, trying not to pull them apart too much. It’s tricky because there are no nogs between studs. So there’s nothing to hold the insulation in place.”
Rather than strip off match lining from interior walls, Lindley often adds layers using a polystyrene glued to the back of gib. “That’s the simplest way of bringing up insulation values. Another way is to take interior or exterior linings off and try to pack in bits of insulation. But it’s fraught because a lot of the framing is rotten. You can also pump insulation through the wall but if there’s no building paper lining, when it leaks, which it often does, it becomes a wet, soggy mess.”
Lindley’s advice is to accept the old for what it is and do superficial things like add insulated plaster board, use heavy curtains over windows, lay new carpet. “As soon as you start opening up the old structure, taking off claddings and linings, you open a can of worms that’s a lot more expensive than you think.
“Leave well alone as far as the old goes and put your efforts into the new. Think passive solar orientation, double glazing and good heating systems.”
Because of the height old buildings sit off the ground, it’s relatively easy to retrofit insulation under old floors and to install a ducted underfloor heating system. Insulate the floor and ceiling, she says. Heat loss is much less through walls. The key with old houses is to make them warm.
“There’s only limited work you can do to the original structure. Focus on the new bit and make it as energy efficient as possible. That’s often around good architect design maximising sun and light. You create the contemporary light-filled area and have a subdued, well-heated older part that makes a nice contrast.”
When Scarlet Architects renovated an old cottage in Middleton Road, Remuera, they completely separated the old from the new, expressing them individually with a minimal upgrade to the old. “We retained a pile of old building material but it came at a price. It was a sustainable decision in that we weren’t throwing the old away.”
To answer the original question, yes, it is possible to create a modern energy efficient home from a heritage villa. But the best, most cost-effective, sustainable decisions are about minimising consumption and energy. More often than not, compromises need to be made.
Scarlet Architects was established in 2000 by architects Jane Aimer and Lindley Naismith. Subsequently they were joined by Mike Dowsett. They believe that great work comes from a high level of personal creativity coupled with an in-depth understanding of the practical requirements of the project. They have a real interest in designing for a sustainable future. Since 2004 they have received seven NZIA Local Awards and two NZIA New Zealand Awards for Architecture.