PassivTerrace: A Passive House Renovation in London

passiveterrace passive house london photo
Images credit The Haringey PassivTerrace

It didn't look like much last summer, an empty, partially burned out row house in London. As part of a Retrofit for the Future programme, Anne Thorne Architects it trying to take the old thing and bring it up to Passivhaus standards, which demand a ton of insulation, really careful installation so that there are no gaps or discontinuities, and very tight sealing. It isn't easy in a new house, and it is really hard on an old one, especially when you want to maintain the look of the house.passiveterrace passive house london photo
Image credit Footprint

In most cases, it is preferred to put the insulation on the outside of the existing masonry. It leaves more room inside; it solves the problem of condensation in the masonry, and if you are trying to build a healthy house without a lot of plastics inside, it is cheaper. But if you want to preserve the look of the house, you don't have a lot of choice.

passiveterrace passive house london photo
Image credit Footprint

That's why Hattie Hartman of the Architect's Journal Sustainability Blog writes:

The approach for the retrofit was 'Fabric First' so high levels of insulation (250mm) and airtightness were key parameters of the project. Consistent with what is proving to be the norm with terraced house retrofits, insulation is external at the rear of the house and internal at the front of the house driven largely by external appearance.

passiveterrace passive house london photo
Image credit Footprint

In a renovation you also don't have a lot of choice when it comes to optimizing window placement and size for maximum solar gain, so a small gas boiler and radiator system has been installed to help out on the coldest days.


Inside they used all healthy materials, including Thermafleece sheep wool insulation for the front facade, cellulose for the party walls, covered with hemp plaster.

passiveterrace passive house london photo

The architects at the official opening, January 17th. The project is well documented with its own blog (which could use more pictures) and on the architects blog. Back at Hattie Hartman's Footprint blog, everyone is complaining about the £200k ($US 320,000) cost of the renovation. They have a point; at that price it is not going to be a model for large scale renovation and upgrading of terrace housing. But it is a bit of an experiment; the house is packed with sensors and is going to be monitored for the next two years.

More at Footprint Blog

More on Passivhaus renovations

A PassivHaus Renovation: Heritage Meets Energy Efficiency
Passivhaus Comes To California, Shattering Stereotypes
Ultra-Urban Passive House Built in New York City
A Picture Worth TEN Thousand Words: A Passivhaus in New York

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Tags: Architects | Energy Efficiency | London | passive house


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