Practice director Fred Guttfield talks about transforming Weir Grove House in Berkshire for a family keen to make a complete break from their previous listed cottage home
Who is the project for and what was their brief?
The client is a family, a couple with two children. They decided to move to Wargrave in Berkshire from nearby Sonning where they lived in a creaky, draughty, listed cottage. They had become fed up not being able to change it to meet their needs, as well as it being cold and disconnected inside from the garden. Instead, they decided to buy a late 1960s brick box on an architecturally mixed development of executive homes – some typical 1960s houses, others with classical features.
The brief was to create all the aspects they had been missing from their previous house; for it to have an amazing connection to the garden, no draughts, for it to be easy to maintain and clean. The house hadn’t been touched since the 1970s and they wanted to make it their own. As the discussions progressed, the client became interested in the existing architecture and that the project should reflect and echo the era in which it was built: essentially modernism with a capital M.
What was the existing building like and what work have you done to it?
The existing house was like a muffin, short and dumpy with a chunky concrete tile roof that was overstressing the structure. The proportions of the roof weren’t working. To the rear, the garden slopes away to a tributary of the River Thames so it is in a flood risk area. This meant there was only a 3.5m deep area in which to extend at the back, which drove the shape of the project. That extension became the dining area.
The second part was a two-storey side extension that absorbs the original garage volume. This made room for the master suite. The roof then became one long span, bridging new and old, helping to elongate the proportions. At ground level, the kitchen at one end of the rear extension slips backwards into the side extension. An opening with an up-and-over glazed roof lines up with the stair and front entrance, and separates the dining space and sitting area.
What was the planning situation?
One of the attractions of the house for the clients was that it wasn’t listed or in a conservation area. From a planning perspective, it was relatively unconstrained, except for the flood plain. There was the usual stuff to be found in this kind of area, including evidence of bats roosting. We had a positive pre-app so we moved to full planning mid-2018.
Explain the external treatment of the project?
The exterior of the rear extension is precast concrete. We came up with this idea while working with the structural engineer on how to achieve the large, glazed opening. Precast could do two things at once: structure and cladding. We had been looking at how to do fluted and splayed features so this approach combined many ideas. There is no steel in the extension supporting the roof. We added red pigment and black aggregate to the concrete to work with the existing brickwork, picking up on some of its colours.
In form, there is a plain horizontal band above the windows like a datum, then the window reveal panels below are fluted and splayed. The clients are geologists and the idea was to make the extension look like it was carved from a single block. The honed fluted lines give the impression of worked stone. Set back from the datum is a powder-coated light grey metal roof trim which matches the colour of the window frames, with sedum contained on the flat areas. The sliding doors are Maxlight, all other glazing was replaced with triple-glazed Velfac. The main roof is fibre cement and the side extension brickwork was carefully mixed to look like the original.
From the front, the house already had one dormer, the second one over the garage contains the master dressing room. The client didn’t want the renovation from the street to be too ostentatious; they wanted a respectful upgrade. The splayed reveals on the front dormers use the same idea as the rear extension but made from Medite Tricoya MDF. It can be made on site and is hand-painted.
How have the interiors have been designed?
The rear extension is one space, comprising kitchen, dining and living room. The joinery became the key to giving each space its own identity. In the dining room there are full-height oak cupboards along the old exterior wall, which are set back into existing window and door reveals. There is also a bar which is set back in this way too. One of the clients’ children is hard of hearing so there is a slated acoustic ceiling above the dining table to cut reverberation time.
Generally, we chose oak for the joinery because it is reminiscent of 1960/70s furniture. The red finger reveals reference the external concrete but also are a nod to the G Plan logo and furniture which was made nearby in High Wickham. This colour reappears throughout the interiors, in the bathroom tile and grout, for example. The kitchen is detailed in the same way as the dining area cupboards but dark-stained to give it its own identity. The stair picks up on black detailing, as well as the oak, and is open tread to give views through from the front door.
In the sitting room, the fireplace is designed in precast concrete with the plain horizontal band across the top then splayed and fluted on the uprights. For the flooring, for about a decade every client came to us asking for polished concrete floors, which there can be many issues with. As an alternative, we often use large-format porcelain printed tiles, which are more economical and lower maintenance.
What was the biggest challenge you faced?
Covid was the biggest challenge. The project went on site in December 2019 and went through two lockdowns. We were both architect and contract administrator, so it was our responsibility to deal with the pandemic. Teamwork got us through. Everyone had to change their expectations; to understand that it would take longer. The contractor had to take on additional costs in prelims and overheads as well as the extra work involved. It was collaborative in the sense of making sure these burdens were shared fairly. We came together more as a team with a can-do attitude.
Explain your favourite detail in the project?
Probably where the band flies across the outside of the rear extension link between the dining and lounge areas is my favourite part. The glass goes behind it and you can see the beam from the inside. It is a modernist thing called a heroic beam. It’s fun and a bit extravagant.
Which aspect would you repeat next time, and what wouldn’t you do?
I enjoyed being able to work on a set of ideas with the client that brought together external and interior elements even to a 1:1 level in the joinery and bathrooms. For example, the bathrooms aren’t all the same, but they have a continuous language.
In terms of what we wouldn’t do next time, the house was designed at the start of 2018. We would be more careful now on the size of the glazed openings and wouldn’t want to use so much precast concrete because of its embodied carbon. We have to think about it in context; this is one extension on a small scale with comparatively small amounts of carbon. Nevertheless, things have moved on a lot in architecture since 2018 and sometimes these decisions can be tricky to go back on once everyone has agreed.
Contract cost £750,000 (turnkey cost including everything from demolition, through to carpets, tiling, kitchen and appliances)
Total area 360m2
GIFA cost per m2 £2,080
Contractor Nicholas Bolt
Precast concrete (inc fireplace) Minsterstone
Joinery and kitchen Creativedge
Extension Glazing Maxlight
Main house glazing Velfac
Piling and Groundworks In Motion