A home in two halves gets a new connecting gallery for its art-loving owners

Can you briefly describe the project that Francisco Sutherland Architects took on?

Set at the crossroads of a private unmade mews in Blackheath, Courtyard House is a single-storey building composed of two cubic brick forms connected by a new barrel-vaulted linkway. 

We were appointed to replace the original fully glazed linkway, upgrade all external doors and windows, floor finishes and lighting. The client also commissioned further interior design and landscape works separately. 

The final result is a thermally comfortable and private home with two courtyards, and a new connecting central space, rather than the previous ‘greenhouse’ linkway which made the house difficult to use. 

Who is the project for, and what was the brief? 

The project is for a couple of retirement age, who were looking for a quiet, single-storey home that could be futureproofed for ageing, with plenty of wall space to display their art collection. The clients had lived in the house for about a year before the project started, so they were well aware of what worked and what needed to change.

The brief was to upgrade the 1980s failing glazed linkway, improve its thermal and energy performance, gain more privacy and provide display space for artwork. The project was part of a wider renovation of the whole house, including the reimagining of the courtyard gardens.

Were there any significant factors that influenced the renovation?

Initially the clients were eager to ease maintenance by simplifying the roof form and lowering the linkway ceiling height. But planners considered that the vaulted roof form made a considerable contribution to the character of the streetscape and conservation area. Both us and the clients are pleased with the final outcome, since the internal vaulted gallery is such an inspiring and uplifting space. 

Can you explain the treatment of the new barrel-vaulted linkway? 

Externally, the vaulted roof is clad in natural zinc for its subtle colour, ribbed texture, malleability and low maintenance. Internally, the vault is lined with plywood, mesh and plaster to provide a continuous smooth surface.

It was not structurally viable to adapt the original aluminium frame to the new roof build-up so the structure was upgraded to a steel frame of 12 pre-curved arches. The vault is completed with timber framing, curved 6mm plywood and 250mm of flexible Rockwool insulation.

The new walls are of traditional cavity wall construction with an outer skin in Belgian grey brick to contrast with the existing red brick.

How have the interiors have been finished? 

The floor to the living rooms and linkway was finished in a honed Moleanos blue limestone and this was retained and extended where needed. We sourced a matching stone to make good the edges that had been disrupted, filling in where previous floor lights and doorways were removed and repolishing it to achieve a final consistent look. Oiled oak planks were used for the bedrooms.

The new walls are a smooth plaster finish to provide a neutral backdrop for the display of art. These contrast with the painted brick texture of the existing blocks.

What has been the project’s approach to sustainability?

The sustainability strategy has been to adopt a passive, fabric-first approach. Air-conditioning units were removed and the thermal insulation upgraded throughout the house. A natural ventilation strategy was developed with louvred ventilation panels installed to the new doors and an opening window at a high level to promote air movement, while maintaining security and reducing solar heat gain. Externally, cables to secure climber plants will further shade the most exposed walls from the sun’s heat.

We retained the existing heating system of boiler, UFH and radiators, in order to avoid waste and extensive rebuilding of the floors and because the system was recently installed and in good working order. 

What was the main challenge that Francisco Sutherland Architects faced?

The main challenge was the structural ‘dentistry’ needed to introduce a new heavier roof and walls while retaining the existing building and avoiding new foundations.

We started with comprehensive research and investigation of the original building and then worked closely with the structural engineer, to achieve the most efficient solution. The new walls, for example, rest on the original footings, with a stepped corbel detail to carry a deeper wall build-up above; and the steel arches rest on new padstones, which were built into the existing walls and clad in brick slips to retain the internal finish of painted exposed brick.  

What is your favourite moment in the project?

As the clients rightly point out, this building is like a Tardis. One of our favourite moments is the surprise as you enter through a ‘compressed’ entrance lobby, with the mezzanine above, into the vast space of the vaulted ‘long gallery’.

Other favourite moments include the new tantalising glimpses of the courtyard gardens from the linkway and the half-moon window framing the view of the trees.

Technically, the bespoke door units with integrated louvered panels are a new and pleasant way to deal with natural ventilation and replace the previously excessive use of AC units.  

Are there lessons from this project which might be applied elsewhere?

The project addresses the common challenge of how to technically and spatially upgrade an older building without radically altering its external appearance and at the same time seeking to enhance the qualities of the original architecture.

The success of the project was due to the process of extensive research into the original and existing building fabric, and then close collaboration with the structural engineer to achieve the least intrusive and most elegant solution.

Francisco Sutherland Architects is a design-led practice in London, specialising in crafted domestic refurbishments, new build residential and community-led projects.

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Key data:

Total contract cost Private  
GIA 234m²
Area of linkway 67m²