Al Scott explores a witty, ductwork pavilion designed by PUP Architects


Al Scott

Jim Stephenson

In considering PUP Architects’ new H-VAC project, which inaugurates an annual ‘antepavilion’ programme, I wondered if my own practice, IF_DO, missed a trick in our recent pavilion in Dulwich for the London Festival of Architecture (AT279). What’s with the ante?

‘Ante’ might describe the relationship of the structure to its site – on the roof of an east London warehouse that now houses artists’ studios – but also contains a suggestion of contradiction or opposition that befits a pavilion designed to provoke. A scaly-skinned, oversized serpent of mechanical cooling, PUP’s invention sits coiled upon the rooftop, casting a scornful eye (or vent) over the Regent’s Canal and the surrounding landscape.

Like our Dulwich Pavilion, PUP’s project was commissioned following a competition (organised by the Art House Foundation and the Architecture Foundation) that offered an alternative to the mainstays of the pavilion world, supporting young architects and enabling recently-formed practices to exercise exuberance with little restriction.

The brief asked competition entrants for proposals that “engage with ideas around innovative and alternative ways of living within the city… and  the use of recycled and recyclable materials”. PUP’s subversive response will surely have delighted Shiva, the site owner and competition funder, which likes to challenge convention whenever the opportunity arises. By designing a structure that falls within the permitted development allowance for roof-top plant, PUP raises the question of why extensions for human habitation are less favoured, and does so boldly and with humour.


In the spirit of transient architecture, of pavilions ante or otherwise, H-VAC makes its impact without being bound to standard architectural process. However, this freedom brings its own challenges and it is clear that PUP has exercised more than just design talent in delivering this project, not least by constructing it themselves with the support of three carpenters and a team of students from Oxford Brookes (where PUP partner Theo Molloy teaches), and delivering to a budget of just £15,000.

By carefully crafting cheap, readily available timber and designing creatively with fully recyclable packaging material for the cladding, PUP has created a beautiful and playful structure demonstrating an agility which must be applauded. PUP claims to be the first architect to use Tetra Pak cartons as a cladding for temporary structures, having tested it previously on a project with students in Latvia. Delivered in sheet form, the material is unused, but surplus to the manufacturer’s requirements and intended for recycling. PUP has cut the sheet into shingles and inverted it, so that the plastic/ aluminium coating forms the pavilion’s external skin. Brilliantly effective, the faceted surface glimmers externally, and creates a dappled interior as light penetrates from the underside of the shingles.


The primary traffic through the duct is not air but people. Entering via an enlarged roof hatch, which provides direct access from one of the artists’ studios within the warehouse, visitors are channeled upward to a seating area at the top, but can also exit through the pavilion to access the rooftop. This is another nice touch by the architects, creating a carefully orchestrated and immersive experience.

H-VAC is first observed at distance, from the canal below, and secondly from within, where the hand-adjustable louvres of the grille offer views back out. Only upon exit is it viewed close-up, when the ‘deceit’ is unavoidable and the structure is understood in an entirely new way, working with the rooftop to create an urban sitooterie.


H-VAC is after all, a pavilion. The ‘ante’ is the statement it shouts from the rooftop. It is where H-VAC differs from other London pavilions we’ve seen this summer: it is not polite. The beauty is in the way the architect sensationalises the mundane, taking external ductwork – a common, regrettable architectural blemish – and elevates it. The great success, aside from demonstrating a respect to craft, attention to detail and pure inventiveness, is that despite its recognisable form and colour, it hasn’t been seen before.

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PUP Architects
Shiva, Architecture Foundation


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