Terrace mettle: How much can you improve the energy performance of a small period house?

When Robert Cohen and Bronwen Manby bought their early Victorian terraced house in Hackney last year they, like many middle-class couples, had their eye on spending a good sum bringing the place up to their high standards. However, it wasn’t a swimming pool or a Smallbones kitchen the pair were after for their £200,000, but an extreme energy refurb.

Manby, who works for charity, the Open Society Foundation, says she’s not interested in choosing fancy knobs for a shiny new kitchen. “I haven’t had any handles on the cabinets in my current kitchen for 12 years,” she says, reclining on a mattress on the floor in the dusty property. “I’ve never really seen the use for them.”

Instead of geegaws and finishes, most of the £150-200,000 budget will be spent on insulation, window upgrades and airtightness measures for the 150-year-old property.

Sustainability consultant Cohen is proud of the different nature of the task: “These are improvements that are rarely pursued with vigour in refurbishment projects,” he says.

This stuff normally gets eked out along the way.

Robert Prewett, Prewett Bizley Architects

He has high hopes for the project: “Given the number of similar dwellings in the UK,” he continues, “a progressive approach to how they may be refurbished most effectively will become an increasingly important factor in reducing carbon emissions in this country.” The pair recking that a standard refurbishment would cost about £150,000, without the energy efficiency improvements.

Team spirit

Cohen’s architect, Robert Prewett of Islington-based Prewett Bizley Architects, appreciates the brief and is convinced by his client’s sense of mission, if a little surprised. “He seems genuinely to want to pursue this agenda; most of the energy here is going into reducing emissions. This stuff normally gets eked out along the way.”

Doesn’t he resent that the project will be more technical than aesthetic? It’s not, he says. “It’s not going to be just technical. The client will get a great space, at the end of the day.” Adds Manby: “A fancy butcher’s block is not as important as a good space. We’re getting a nice stove, mind you.”

The whole family’s in on the act. Bronwen Manby's brother, Dave, is working as builder on the project. Today he was meant to be starting on site, but one of his workers is in "marital difficulties", so he has had to wait. Dave is no ordinary builder. He trained as a civil engineer.

“It’s going to be fairly bog standard,” he says optimistically. “I reckon the heat recovery system will come with an instruction booklet.”

Dave’s sanguine state of mind is probably at least somewhat due to the similar work he has done in the French Alps. But he recognises that such refurbishments are not as common around these parts. “Last thing I’ll have to put in is a turnstile,” he says.

As work on the project continues, we will follow the team – client, architect and builder – as they attempt to drastically improve air tightness and U-values - by at least a factor of ten. The house at present has a D-rated EPC certificate. Cohen wants to bring it up to Code for Sustainable Homes level four.

We will be following the project from demolition through to completion with updates, photos and videos. Cohen, Prewett and the Manbies will help us keep up to date with their progress from the site.