We are delighted to have completed this project in Camden Town, winner of two RIBA London 2019 awards and two Construction Excellence awards. It is a new-build Passivhaus on an urban infill site, previously the client’s garden.
Designed by bere:architects who were given a free hand by the client Max Fordham, it features a number of bespoke elements conceived by Max such as internal shutters constructed from insulation board to be controlled by the smart-home system. No additional heating systems have been installed.
Max decided to avoid unneccessary cosmetic features that would detract from the main focus of the project, which is to demonstrate a technical concept that could have widespread benefits for retrofit and low-cost housing sectors.
The building – with its thermally massive structure, effective window opening areas, glossy white external finishes to window shutters and effective night-time ventilation – is also designed to stay comfortable in extremely hot weather. Its peak measured internal temperature was 28°C on 25 July 2019, when London reached 38°C during the record-breaking heatwave.
Building a new house on a small infill site along a narrow, cobbled mews brought spatial and planning constraints, however. Planted terraces were necessary to reduce overlooking to neighbours, but this meant a bigger thermal envelope and smaller roof area for the PV – ultimately thwarting the zero-heating aspiration.
After one year of occupation, the energy supply and demand were: space heating 2,253kWh; domestic hot water 1,836kWh; small power and lighting 2,217kWh; and PV generation 3,641kWh
The space heating demand is much higher than the project’s ambitions, partly because of the initial warm-up of the thermally massive house, which was completed in winter. Space heating is provided by a single 2kW electric heating coil in a common supply duct, controlled on return air temperature.
The judges noted the building’s maximisation of daylight and warm lighting. Occupied spaces are largely orientated south-east, which gives morning and midday direct sun, and a more characterful spectrum of light than diffuse daylight only. Artificial lights are generally off during the day.
Inclusivity aspects, and separation for ageing occupants, also impressed the judges. Plumbing connections have been built in so the upper part of the building could become a second dwelling should the ground floor become a self-contained flat without stairs. The flooring throughout is cork, which helps with acoustic character and offers some protection from falls.
Another plus with this project was the consideration of embodied energy, well ahead of current requirements.
“My projects with Bow Tie are the only ones where I’ve left the contractor to follow my airtightness details and the projects have passed the 1st airtightness test.”
“Rafael is particularly knowledgeable about green issues and we now have a kitchen/breakfast room which is easy and cheap to heat in the winter and cool in the summer.”
“We’re really lucky to have Bow Tie Construction working on our project. Thanks for all your fantastic work so far.”
“I did get the benefit of regular updates and involvement in the project so I could see the quality of the work.”
“Bow Tie Construction were very professional, they did things to a very high standard and paid a lot of attention to detail. When small issues were flagged here or there they were always keen to investigate and fix them.”