Technical Envelope

LAID BARE

The remarkable textured façade of Clerkenwell’s Turnmill Building was created using 85,890 handmade Danish bricks that took 27 different forms. This was not for the faint hearted, as Stephen Cousins discovered

STANDING INSIDE the plush atrium of the 70,500sq ft Turnmill building and retail building in Clerkenwell, there’s a sudden sense of disorientation as I realise that I stood on the very same spot 15 years ago, when queuing to enter the (in)famous Turnmills nightclub. In those days, the club occupied the

cavernous basement of a warehouse that was constructed in 1886 for the Great Northern Railway Company. Now, that solid, unadorned structure has been knocked down and carted away, and in its place is a bright and airy six-storey retail and offi ce block, with pristine white plaster walls, polished screed fl oors and shiny brass lifts and light fi ttings. But similarities remain, as the new

Turnmill building – designed by architect Piercy & Co and built by McLaren Construction – shares much of the character of its predecessor. Most notably, it's been given a robust, buff-coloured facade made up of 85,690 handcrafted clay bricks, punched-in industrial-style windows and deep brick reveals. The Roman format bricks, made by Danish fi rm Petersen Tegl, are longer and thinner than London stock, giving the elevations the appearance of textured fabric when viewed from a distance. Known as Kolumba bricks, they were developed in 2000 in collaboration with

30 | JANUARY 2015 | CONSTRUCTION MANAGER

Swiss architect Peter Zumthor for the Kolumba Museum in Cologne. Although most of the bricks were

laid traditionally by subcontractor Swift Brickwork, prefabricated concrete lintels also form part of the cladding system. The aim of the lintels was to maximise space inside the offi ces by avoiding the need for a thick, loadbearing facade. And by taking brick-laying off the critical path, it could be carried out in parallel with other operations, which meant the building could be made weathertight earlier. Laying the bricks was a challenge, as the design required them to satisfy tight tolerances. Mike Vorster, McLaren’s regional design manager, said: “None of Swift's team had worked with the Kolumba bricks before, so there was a steep learning curve. Then there were the 17,000 “specials” [27 types of bespoke brick, many of them curved] used to create complex details – including door numbers for the two ground-fl oor shops.”

Why the warehouse had to go The decision to demolish the existing building, apart from its retaining wall at basement level, was not an easy one. Turnmill had a rich history: its original purpose was to stable the horses that pulled the carriages of an underground railway, and it was also one of the earliest