Or how an architect found its ideal supplier … This week Sonia Soltani tells the tale of Pascall + Watson and Belgian concrete firm Decomo

When Bob Barlov worked as project architect on the £53m expansion of Wembley Park underground station in London, he chose a Belgian precast concrete supplier called Decomo. The station opened earlier this year and after that happy collaboration, Decomo opened an office in London and is working on office projects in the City.

What was your original vision?

The brief was to enlarge the underground station and increase the staff accommodation to fit in with works being carried out at Wembley stadium. The accommodation was designed as a low office building and we built stairs and lifts to the platforms to increase the station’s capacity. We chose to use precast concrete cladding early on because it’s durable and robust in a high-exposure environment where there’s a lot of public interface and abuse of materials.

Why did you choose to work with a Belgian company?

I’d seen Decomo’s work at Fulham Broadway station and got in touch with the company. Its people came to London to discuss the project without charging us so that we could develop the design. Continental firms have more experience of precast concrete. In the UK, the material has a bad reputation because of the failures of the 1950s and 1960s. There was such an outcry against it that it seems technological development stopped from that point.

How did you collaborate on the design phase of the project?

We met and they presented the work to me.

I found them extremely helpful and willing to listen and understand our project. They didn’t suggest any changes. As a practice, we had a limited knowledge of how best to use precast concrete so we relied on their advice. They sent us a lot of samples and invited me to see how the cladding was made in their factory in Belgium. I wanted a reddish-brown finish for the cladding. Decomo sent me three samples until I found what I wanted. We completed the design with their help.

The new Wembley Park underground station, complete with creamy, acid-etched Belgian cladding
The new Wembley Park underground station, complete with creamy, acid-etched Belgian cladding

In which way was Decomo more competitive than its UK counterparts?

When Taylor Woodrow, the main contractor, put the cladding package out to tender, it chose Decomo over the British companies because of the lower cost. It’s remarkable that Decomo’s technology was so advanced that it managed to make the cost of manufacturing competitive, even taking into account transport costs. It was 5% to 10% cheaper than the others because its manufacturing costs were 15% lower than those made in the UK.

What did you specify?

After looking at the different kinds of cladding on offer, we chose two types:

cream-coloured acid-etched because it’s textured, and a polished finish that has a terracotta colour and is more easy to clean and wash. We developed the specification drawings together and, because Decomo anticipated all the difficulties, it made it easier for us.

How did the Building Regulations affect the specification?

To comply with Part L and get approval from the local authorities, we had to provide excellent insulation. Decomo’s panels comprise a polystyrene layer that is bonded to the concrete. There is no tradition of this in the UK, but it has been done on the Continent since the 1950s and is fairly standard practice there.

What do you think of the result?

It is exactly what we were looking for. Without Decomo’s help, we wouldn’t have known what was possible. Every time we suggested something, Decomo’s people came back to us immediately with ideas. They were very interested in making our ideas feasible.

I think it has been the most successful package on the project. I’d have trouble finding fault with it.