Victorian Terrace House Transformed with a Deep Energy Retrofit

Planning & Progress

The plans were submitted to Camden London Borough Council, which was the start of an eight-month journey. “The planning process was extremely slow because there was a backlog from Covid,” says Camille. The council was happy with most of the proposed design, but requested a few minor changes.

“The house lies in a conservation area, so any upgrades to the building fabric had to be achieved without affecting its outward appearance,” Gill explains. “This required a complex set of insulation details, where exposed brickwork was insulated internally and new construction insulated externally. We were also forced to have an expensive acoustic test carried out in order to install the heat pump.”

The dining room is located in the new side return extension. A juxtaposition of old and new, the space is defined by an antique dining table that Camille inherited from her grandparents. A new flat roof window draws light into the space, while a bespoke window seat provides idyllic views of the rear garden

Luckily, Gill had a great relationship with the council and was able to provide advice about how to respect their wishes, without compromising too much on the design. “Gill was very respectful of what I wanted and good at offering alternatives,” says Camille.

Once permission was achieved, the project was put out to tender and one of the companies, Amirilan Contractors, came highly recommended by Gill. “I trusted Gill implicitly about hiring the correct people for the job,” she says. “Amirilan had recently completed a beautiful project for a family friend, so I knew they would do a fantastic job.”

Setbacks & Special Details

Work began with the construction of the side return extension and at the rear, about 170mm of earth was excavated to improve the ceiling height in the existing kitchen. Next, the staircase was relocated and some of the ground floor walls were removed.

“There were a number of challenges to overcome once the house was opened up,” says Camille. “For example, the brickwork at the front was bowed and required special attention.”

Originally located in the middle of the house, the staircase now sits neatly against one wall. Designed by Higginson, the timber flight is crafted from Douglas fir and has a bespoke steel rod balustrade

This involved straightening out the bend to create a flat surface for the internal insulation boards, without compromising on the wall’s breathability or creating a gap between the boards and the brickwork, which could lead to interstitial condensation.

“We applied thin layers of Diathonite, an insulating plaster, to the wall,” says Gill. “The build-up was about 70mm in the middle, feathering out to a minimum at the top and bottom. Insulation boards were then fixed to this new flat surface.”

The availability of materials also proved challenging. “Cork insulation boards were completely unavailable, so we opted for wood fibre alternatives,” says Camille. “However, to me the project seemed fairly seamless, because I took a back step and let the team handle everything.”

Amirilan took on project management duties for the construction sequencing, with Gill overseeing the work. “I was kept in the loop and the team was very upfront about any issues,” says Camille. Renting nearby, Camille visited the site almost every week to check on progress.

A Sustainable Retrofit

When Camille bought the property, she wanted to overhaul it, but undertaking a sustainable retrofit hadn’t really been the plan. “I’d thought about making the home more energy-efficient, but this was my first project so I didn’t know how it could be done,” says Camille. “The house needed a lot of work, so Gill said we might as well start from scratch and make the home more economical to run.”

Gill’s proposed deep energy retrofit would significantly improve the performance of the house, through upgraded insulation and airtightness, and key green materials such as lime plaster and render. “We’ve demonstrated that a house in a conservation area can be successfully retrofitted to achieve a very high environmental performance,” says Gill. “We were fortunate to have a fantastic contractor who paid great attention to details. Our careful detailing and his excellent workmanship were rewarded with an airtightness result of 0.9 – very good for a property of this type.”

The side return extension created space for a new dining room, simultaneously increasing the footprint of the kitchen.

For those thinking of undertaking a deep energy retrofit, Gill recommends allowing plenty of time for planning. “Make sure you have a contractor who buys into the principles of airtight construction,” she says. “It’s a departure from what most are used to and needs great attention to detail.”

Gill also suggests airtightness testing to ensure everything has been properly installed. “Do this before the finishes go on, so it’s easy to rectify any problems. You can successfully upgrade a period home in one go, or in stages, but seek professional advice and ensure you ventilate properly,” says Gill.

Approaching the Finish Line

Due to material delays, the project ran over by around seven months, with Camille moving in a few weeks before the house was finished. Completely updated, the Victorian terrace is now bright, modern and perfectly suited to Camille’s lifestyle. The front door opens into a spacious living room, which flows through to a study, dining room and kitchen, with ample glazing creating a  great connection to the garden. A new shower room and utility sit behind the new staircase, which leads up to the first floor. Here, two bedrooms and a spacious bathroom can be found.

Sleek, simple and light interior finishes were specified throughout, helping to enhance the feeling of space inside the compact home

As for interior design, the home’s natural and reclaimed materials, such as terracotta floor tiles and lime plaster walls, take centre stage. Gorgeous joinery and bespoke details add to the character of this simple yet impactful home. “My favourite space is the bathroom,” Camille says.

“It’s beautifully designed and made.” As for the most rewarding part of the project, Camille loved watching plans on paper being brough to life. “You talk about how the house might look and how light might fill the rooms, so seeing it come together as you had envisioned is a brilliant experience,” she says.

To increase ceiling height in the existing kitchen, the floor was lowered by around 170mm. Finished with lime plaster walls, bespoke joinery, a circular skylight and terracotta floor tiles – reclaimed roof tiles from Italy – the kitchen is simple yet incredibly elegant

The house not only suits Camille’s lifestyle, but it is extremely energy efficient. “It’s cosy all year around,” Camille says. “It has a great kitchen and works well for hosting. I love being able to enjoy the different living spaces.” There are a few small things that Camille might do differently if she had her time again, but on the whole, she’s thrilled with the results.

“Until your house is finished, you don’t know how it will be to live in,” she says. “There’s a weird world of difference between the house plan drawings and the actual thing, so I might change a few things in the future to better suit how I use and live in the space. But for now, I have no plans to undertake another project. This is the home where I see myself for a very long time.”