Hillary EnerPHit.

The clients’ commitment to living on this site is commendable. So is their flexibility: this knockdown-rebuild project morphed into a deep retrofit that harmonises the best of old and new.

The clients had lived at this address for decades. They’d raised their children here and they didn’t want to leave this suburb. They came to Envirotecture thinking the house simply couldn’t be fixed—the renovation done on the 1930s two-story house in the early ‘00s hadn’t made the house any easier to live in.

Envirotecture director Andy Marlow is characteristically blunt in his explanation of what they discovered. “Like every other renovation project, the old part of the house was great and could be fixed. But the renovation done a few years back was unfortunate, it was badly designed and not very well built. There was poor connection between the house and its garden. It fundamentally didn’t work and it was uncomfortable—the owners got through winters by piling on jerseys.”

And so, a brief was taken for a knock down rebuild. But then an interesting thing happened. As the floor plan developed, Andy and his team couldn’t help but notice how similar it was to the original house. That’s when they went back to the clients with an unexpected proposal: what if the old house could be fixed? (This is explored in detail in this post.)

It speaks of the trust already developed between client and architect that the owners were willing to consider another renovation. That trust was rewarded because they now have the best of both worlds; the art deco character and familiarity of the original house plus a new extension with a beautifully workable floor plan and gorgeous connection to the garden. (There was a small consolation with regard to the regrettable ‘00s extension: it had beautiful floorboards and Envirotecture made a point of re-using them.)

All this is wrapped up in a new airtight building envelope featuring all the Passivhaus components, ensuring a warm, comfortable and healthy home. In fact the building surpassed the requirements for a PHI retrofit (the EnerPHit standard) and qualifies as a Passivhaus classic. That outstanding result flowed from good architectural detailing and a lot of good execution by great builders with Passivhaus experience who had worked with Envirotecture before. Interestingly, the render on the exterior of the original masonry acts as the airtight layer.

There are several design elements that weave together the old and the new, inside and outside. The new extension is clad in narrow vertical timber cladding, which also features on a dramatic wall that leads from the kitchen to the living room. The front door sits in a curved wall, behind which the staircase winds up to the first floor. The kitchen wall echoes this same curve.