Facing the challenge of how to bring a Victorian home with damp old brick walls up to a modern low energy standard, architect Brendan O’Connor deployed an innovative solution: build entirely new and superinsulated timber frame walls within the old structure.

With obsessive attention to preserving and restoring the original fabric of these two Victorian townhouses, and a commitment to shunning petrochemicals and using only natural materials, could this be the most wildly ambitious and sustainable passive retrofit ever undertaken in the UK?

Old buildings are tricky to upgrade – especially if external insulation’s not allowed. Utilising a combination of cutting edge building physics and a carefully selected palette of insulation materials, one Victorian stone building has been upgraded to the Passive House Institute’s Enerphit standard, slashing heating demand by 90%

Built in 1850, this home in Dartmoor national park would have relied on local timber supplies for heating until the advent of widely-available central heating. One passive house-flavoured retrofit later, it’s back to its wood-burning roots – only this time with much less wood use, and much higher comfort.

Upgrading a historic home to the passive house standard typically means leaving the façade untouched to preserve the building’s historic appearance, but the team behind this fully passive retrofit in Kensal Green took a totally different approach. 

This pioneering upgrade project, completed in 2009, turned a Victorian redbrick in Birmingham into one of the UK’s greenest homes. Along with a much wider ecological agenda, the house employed fabric first principles of insulation and airtightness, and met passive house design targets at a time when the standard was still in its infancy in the UK.

There was a time when insulating an historic property meant treading lightly on its building fabric. But today, guided by building physics, passive house designers continue to push the boundaries of retrofit by bringing old homes up to modern standards of super-insulation. This project is the third such deep retrofit to an historic London property by Green Tomato Energy.

Architectural technician Phillip Newbold overcame strict planning rules and a tight budget to build his sensitively designed, super low energy home in an area of outstanding natural beauty.

Turning an old Victorian home into a passive house is a painstaking job that would frighten many building professionals. But the team behind this innovative retrofit didn't just end up with a certified passive house, they got one of the lowest energy dwellings in the UK.