OEB architects have recently completed a highly insulated refurbishment and extension of a townhouse in North London, to meet the low-energy Passivhaus EnerPHit standard. Zinc clad extensions at roof and rear are simple and rectilinear, sensitive to the site’s location within a Conservation Area. The interior combines minimalist white-lined rooms with storage spaces that open up to reveal a warm and adaptable plywood structure and brightly coloured exposed services.
BRIEF AND DESIGN
The clients’ brief for Lawford Road was to create a minimalist, intelligent, and energy efficient refurbishment of a Victorian property, forming a family home that would allow spaces to adapt over the years. The Passivhaus standard required an entirely new insulated timber frame to be built inside the existing brick shell. OEB took the opportunity given by this new structure to reconfigure the internal layout. Rooms are defined by a series of 900mm deep storage walls placed orthogonally across the plan, while plain white surfaces line the interior.
The storage walls give a sense of solidity to the new construction, and contain all the built-in functions of the house: kitchen, WCs, desk, and plant. When opened up, the interiors of these elements reveal warm plywood timber finishes and exposed services accentuated in bright colours, contrasting with the outer plainness of the rooms. Solid oak flooring is used throughout and continues onto the new staircase with flush treads and risers, where a lightly reflective white ribbon balustrade runs continuously up through the full height of the house.
The new second floor study is located in a zinc rooftop extension over the rear outrigger. Here the plywood structure remains exposed, as if this space is a habitable version of the storage elements elsewhere, or like climbing into an attic. The joints between the components are not hidden: the room is clearly made from different parts connected together with exposed screws, notches and lap joints. Simple and adjustable open shelving spans between the plywood posts, where objects and book can be on show.
‘The result is impressive. The clean white surfaces, paired with warming wood, are an obvious match for our aesthetic - but the house is deeper than that. The use of a single system of modular plywood components throughout the house will allow us to adapt it as our needs change, key to the long term sustainability of the building. The insulation and airtightness measures have led to a house that is not only efficient, but comfortable everywhere - it’s strangely pleasant to live without draughts. As an engineer, though, my favourite aspect is how it’s possible to see through the white skin of the building, into its wooden structure and colour coded services, simply by opening a cupboard door or entering the study. We’re looking forward to seeing how the building works with us in the coming years.’
Andrew- client
PASSIVHAUS STANDARD
The clients were keen to create a house that was highly energy efficient but also very comfortable. The Passivhaus EnerPHit standard for refurbishments provides this: very high levels of insulation and airtightness create a constant even temperature throughout the house, no matter how hot or cold it may be outside. Mechanical ventilation then responds dynamically to replace stale air with the perfect level of pre-heated, filtered fresh air. To achieve this high performance the existing internal structure of the property was completely removed, leaving a three-storey void within the brick shell.
A new highly insulated and independent plywood timber frame building was then carefully constructed, held away from the cold exterior brickwork - a building within a building. This level of intervention was made necessary by the constraints of the existing house, such as the building’s north-facing rear elevation, which make it not naturally conducive to minimising heat demand through other means. Air tightness is achieved using robust Smartply propassiv board, and the highest quality windows and doors were specified, including triple-glazed replacement sashes.
HOME AUTOMATION
The client, a software engineer, was keen to integrate a smart-home system into the project from the outset. Products have been specified that will allow him to write his own code to learn from and automate elements of the house:
‘Building automation follows the overall minimalist brief. Unobtrusive sensors in each room continually monitor indoor air quality, feeding back to the ventilation system. Interior lighting automatically tracks the daylight outside, from a cool midday to cosy dusk. A custom digital simulation of the house predicts interior temperature, closing reflective blinds and opening windows to prevent overheating, while determining whether solar power is best used to charge batteries or heat water.
Despite the advanced technology, wall mounted controls are traditional and familiar rather than glowing screens. Significant effort was spent ensuring the technology can grow with the evolving needs of current and future owners, like the plywood cabinetry, modular, standard and interchangeable components allow pieces of the system to iteratively adapt to the future.’
Andrew- client
The web of smart-home services are made visible throughout the house, threading through the plywood in brightly coloured powder coated conduit. This highlighting is not unambiguously celebratory, acting as momentary reminder that smart technologies do have some physicality somewhere, with material effects on the residents and the wider environment.
