Design, buy, build: how Craftworks delivers the full package

What is Craftworks’ background?

It was a response to the idea that ‘no-one listens to architects and no-one trusts a developer!’ I set up in 2005, using my student loan, as a one-stop architect/developer/contractor and we’ve not had a client since. It upends the traditional architect role; we are manufacturers of sorts, designing, making and selling a product – buildings. We love the agency it gives us – a direct relationship with a building’s construction that avoids all the contracts and administration complexities. We are working at a range of scales; nine flats here but also nine houses in Bermondsey and 24 apartments in Southwark. There are 15 of us in Craftworks but we also have our own building firm that fluctuates between 25-50 people, who are able to move around our live sites. 

So what are the challenges?

There’s not necessarily more profit as there are inefficiencies bound into using your own labour. There’s the day-to-day complexity of project management – you can be buying every nut and bolt being used on site while discharging planning conditions and juggling lead times. The range of work demands a lot from our staff and architects from normal practices can find it hard to assimilate. They have to leave what they’ve learned, at the door – it’s almost be a different career. Clyde Russell, the architect who worked on Villa Fontaine, has developed every detail and handled every component that’s been installed; he’s connected to every interface. 

What was its planning context?

Sydenham Hill was historically affluent and when we designed this apartment block, we wanted it to look as if it was part of the area’s well-established villa typology; this was what we took to the planners. On the front we put a contemporary interpretation of the classic facade of large bay windows and inset loggias, all in Petersen K48 brickwork. The building essentially has front and back facades – flank walls are blank – as much for simplicity and cost as to respect neighbours. Side and rear elevations have rainscreen cladding outer face of Petersen C48 240mm wall-hung tiles on rails fixed to timber studs, which gives it a strong sense of barn-like agricultural building. Planners were sold on this aspect, its formal symmetry, the hipped roof with its ‘kick’ and more diminutive dormers. It went through quite easily.

What was your structural approach for the block?

We are building six single-occupancy houses out of CLT nearby and while there was no problem with it there, it became impossible to use for a multiple-occupancy residential building. The design had to perform from fire, thermal mass and acoustics perspectives and that ultimately drove the decision to go with a hybrid concrete frame structure. We did mitigate this by using 175mm-thick insulated clay block Poroton walls as the infill structure, with lower embodied carbon and great thermal properties.

We also used tri-ply timber as permanent formwork for cast floor slabs to become the ceiling soffit finish. It’s used as the lining for internal metal stud partition walls too, helping create the acoustic performance you’d expect from a higher-end scheme. The timber stairs were prefabricated off-site, brought in and assembled over four days. The Petersen Kolumba bricks and tiles specified were as good as we could afford. It might look like we’re being on trend but as architect developers we have genuine investment in our material choices. 

What about the internal design and linings?

A priority was to create a lot of storage space lining the internal corridors, with ample provision for washing machines and larger items. These were built-in and formed from CNC-cut ply, with phenolic-finish doors sourced from Finland. The interior material palette is very simple and specific, with exposed tri-ply timber finishes or clay plaster walls. We use this on internal bathrooms too as it’s porous and breathable. 

Internal compartment walls are Poroton clay blocks infilled with concrete and tri-ply and insulation while partition walls are tri-ply either side of metal studs. All electrics run along them and anticipate potential bed positions for instance, building flexibility into the design. Floors are made up of 175mm concrete on 18mm spruce tri-ply with 20mm insulation, 45mm poured screed and an 18mm solid Douglas fir T&G floor. Bathrooms have underfloor heating beneath a linoleum finish.

The kitchens’ timber joinery was designed by us with high-quality cast worktops. Cooker hoods are a pet hate of mine, so we just used a high-power fan that vents directly out through the infill wall. The reaction by purchasers to this ‘exposed’ aesthetic generally has been really positive.

On  the lower ground floor we had large hinged doors and fixed glazing leading out to the terrace, as this was cheaper than bi-folds. Double-glazed timber doors and windows were by Nathan McCarter Joinery – it took two days just to source the brass handles that we wanted at a price that we were prepared to pay. The rooflights that we fitted in the  central part of the top floor penthouse were by Roofglaze. And as we were buying in bulk, we managed to negotiate a good deal with CP Hart for the bathroom baths, sinks and brassware.

How did you co-ordinate service runs?

We didn’t use a services engineer so had to design the heating, plumbing and ventilation runs ourselves. This appears back-to-back between kitchens and bathrooms in plan, as risers running up the centre of the building. They are super-efficient area-wise.

We ensured, for instance, that boiler flues ran directly out to flank walls to avoid high level duct runs, which would have meant dropped ceilings and lowered our generous door heights. Some of the plumbing and MEV service run is behind a bespoke hinged access panel in the shower wall and is compressed, fully integrated and co-ordinated. 
Most service engineers would just allocate an oversized riser to all this, but we wanted every inch to work as real estate for us if possible. Although nobody sees it, we and the operatives that installed it are really proud of it. It took time to design, was executed with a high level of craft and the finished job looks like it belongs in a submarine!   

What are the lessons learned?

Every project we do challenges us to consider the cost of good design and how we add value. The build was expensive – at around £3500/m2 – but it was affected by Grenfell, the Covid pandemic and rising inflation rates due to the war in Ukraine. This all had knock-on effect on design, programme and material costs which we had to respond to by changing the specification as we went along. On reflection we might have avoided the hip roof to the penthouse flat, and one of its bedrooms is top-lit only, and we might have introduced more efficiencies in plan. 

We made around a 15% profit on this one – lower than originally envisaged but we’re not a hard-nosed developer expecting a 25% margin. Circumstances forced us to keep revisiting the design to see how we could make it work harder without compromising the build quality we wanted. We get more savvy with every project we complete, but one thing’s for sure – we will be using those Poroton blocks again!