A mesh of slippage: Amin Taha has fun with heritage

Visitors arriving in London’s Hatton Garden jewellery district could be forgiven for thinking the imposing terrace of buildings that draws the eye on the corner of Bleeding Heart Yard and Greville Street is historic. After all, this is a conservation area brimming with heritage – the evocatively-named Bleeding Heart Yard itself pops up in Charles Dickens’s Little Dorrit.

But drawing nearer, attentive observers, when not dazzled by the sparklers in the nearby shop windows, may be intrigued to realise that the sturdy-seeming facade is in fact covered in an intriguing mesh. Not only that, something is afoot with the configuration of architectural elements, which on closer scrutiny appear to have slipped around in unexpected and unruly ways. 

What is going on? This playful composition of new from old is the work of Amin Taha’s Groupwork practice, which was commissioned by developer Seaforth Land to upgrade the 1970s office building on the historic site. The project extends and reworks the incumbent building to give it a new lease of life, thanks in no small part to an over-cladding that drastically improves energy efficiency while reinventing its appearance. And the practice has had fun here too, says Taha, exploring nostalgia for the past with a twist of its own.

The 8 Bleeding Heart Yard project shows rather more sensitivity to its context than the site got in the late 1960s, the last time it was comprehensively tackled. Then, the developer demolished a terrace of eight buildings dating variously from the early 18th to early 20th century, replacing it with a five-storey corner building and consigning the famous rear yard to car-parking. Visually, the replacement building was fairly nondescript, with a horizontal ribbon of windows and a blind brick facade at street level. Structurally it was sound – the concrete frame could support extra floors – but a big internal re-organisation was required after years of sub-divisions and accretions. 

By the time Groupwork came on board two proposals to extend the building for a previous owner had come to nothing – permission to increase the building’s size in the conservation area clearly needed a compelling proposition. The practice’s instinct was to look to the past, commissioning heritage consultancy Donald Insall Associates to investigate what had existed previously on the historic site and its surroundings, and use this knowledge to inform the reinvention.

At the same time as this research into the site’s history, the practice was developing its own embodied carbon material methodology to determine what to keep and what to replace. It used the BS EN15978 standard for lifetime embodied carbon accounting and the Inventory of Carbon and Energy database, which gives the embodied carbon of over 200 materials. 

As a result Groupwork has retained most of the building, with the exception of its single glazed windows and accumulated plasterboard internal additions, while adding insulation and radically altering its external appearance. Internally, the removal of partitions and corridors has created open plan office accommodation. Meanwhile, the upwards (two storeys) and side extensions were created in a deeply insulated structure of glulam beams and CLT floors, walls and roof. The result transforms the building inside and out, doubling the original GIA of 3386m².

The practice first explored what Taha calls a ‘technically-oriented’ facade design with louvres to keep the sun out, before  embracing a playful interpretation of the  buildings that once occupied the site.

In doing so, Groupwork has drawn on both the heritage report and its long-established interest in using – and subverting – memory and nostalgia as an opportunity for architectural expression, a creative thread that dates back a couple of decades to an unrealised proposal for a residential building on Bayswater Road facing Hyde Park, conceived as a Belle Epoque-inspired palazzo. More recently, the practice completed 168 Upper Street, to deliver a creative interpretation cast in terracotta-coloured concrete of the long-lost Victorian corner building that once occupied the site. At Bleeding Heart Yard, the tongue-in-cheek composition turns to the past by reinstating historic facades, but does so with telling changes that are not instantly obvious. These include missing pieces of entablature and other architectural elements – seemingly load-bearing pilasters and columns don’t actually touch the ground. The veil of 1.5mm mesh further plays with expectations by replacing the solidity so often associated with the past with lightness. 

The practice calls it ‘misremembered, corrupted and a trick to our nostalgic expectations’. 

References abound. A conversation with Taha about the project careers dizzily through Gottfried Semper, John Ruskin, Robert Venturi and po-mo, Rachel Whiteread and many more. With some regret, the practice says it can’t in any way claim to be the first to play around with historical precedents in this way. It cites Guilio Romano’s Palazzo del Te in Mantua, Italy, in the 16th century and, rather more recently, the work of Diener & Diener at Berlin’s Museum of Natural History and Do Ho Suh, a Korean artist who creates ghostly architectural structures using translucent fabric. 

In the new facade build-up for 8 Bleeding Heart Yard, 250mm of Rockwool cavity insulation was added to an internal layer of blockwork that had been introduced to supplement the original half-brick outer wall in the 1980s. Externally, the envelope gained a further 250mm of insulation on the rear and sides, and 150mm on the facade. This is faced with a robust, black, breather membrane by Illbruck and folded metal mesh panels by Dmitro Facades in depths ranging from 50mm to 1200mm. These are fixed back to brackets on the brickwork mounted on vertical rails. New windows are by Reynaers. Overall, the U-value of the wall is now 0.13.

On the facade of the extension, the wall build up consists of 200mm of CLT, 250mm of Rockwall insulation, vapour barrier and mesh.

The practice collaborated with Winthill Metalworks and Working Metals to create two prototypes using brass panels. A sample area was installed on the building for many months during the planning process, to ensure no surprises later. The metal was pre-patinated in acid, and had a perforation ratio of 70% solid:30% holes at the base, rising to 50:50 then 30:70 higher up the building. Holes of different shapes and sizes were explored, with round giving greater strength. The introduction of folds into the mesh panels gave further strength, as well as allowing the architect to model the facade in response to the original buildings. Fixings were exposed for honesty and ease of maintenance. 

Despite the success of the brass prototype – which was within budget – the contractor chose the more widely-used aluminium for the final build. This involved a hand-finish applied in-situ with rollers and brushes via cherry pickers to give the required variation of tone.

Taha hopes that people will enjoy the humour of the composition and is unconcerned that some may take the playful facade on face value as original. The critique of nostalgia is clearly a rich vein with, he hopes, much more to explore on further projects. But even if the games he’s playing will pass many by, there’s nothing fanciful about the impact of the over-cladding. In combination with air source heat pumps, new windows and part passive environmental controls, it has reduced energy consumption to 35kwh/m²/yr, which equates to a fall in reduced operational carbon to 4kgCO₂/m²/year across an expected 70 year lifespan. This relates to a Leti target of 55 kWh/m²/yr, which would equate to 7.48kgCO₂/m²/year.