AJ Retrofit Awards 2023 winners revealed

Retrofit of the Year

Park Hill Phase 2 by Mikhail Riches (Winner in the Housing and Listed Building £5 million and over categories)

That it won in both the Housing and Listed Building £5 million and over categories is a measure of the success of this scheme, which balances the sensitive upgrade of a 1960s housing estate’s Brutalist fabric with its transformation back into a decent place to live. As a project, it embodies everything these awards advocate: from decarbonisation to social sustainability. It demonstrates how good collaboration and learnings can create something that, although specific to its context, can be rolled out on other schemes – and yields lessons for retrofitting other high-profile post-war projects.

The second phase of the redevelopment of the celebrated Park Hill estate in Sheffield is more modest and subtle than its Stirling Prize-nominated first phase, completed nearly 10 years ago. The light-touch approach taken by Mikhail Riches included insulating the existing brickwork internally and carefully cleaning it externally. The design built on lessons from Phase 1 and on conversations with tenants, but it was also informed by observations of how the structure has been personalised by its residents – including through the use of colour. The ‘streets in the sky’ concept has been revived and a sense of community restored.

Back in November, Rob Wilson wrote of the scheme in the AJ: ‘The thorough research and deft hand that Mikhail Riches has brought to it has impressively future-proofed this listed building while remaining seamlessly in tune with the spirit of the original design.’ This is what retrofit is all about. FW

Cultural and Religious Building £5 million and over

Sponsored by VMZINC

The Burrell Collection by John McAslan + Partners

‘It’s a measured, almost surgical approach – a grown-up retrofit,’ said one judge of this deserving winner. ‘Truly exemplary,’ said another. ‘The team has demonstrated how retrofit is about more than mitigation. It's about improvement.’

The transformation of The Burrell Collection balances restoration and modernisation on one of the few Category A-listed post-war Scottish buildings.

In recent years the building had suffered from water ingress, poor energy performance, issues with accessibility and a lack of flexibility. Through careful internal interventions, an additional 35 per cent of display space has been created within the existing building envelope. A key move has seen a redundant lecture theatre replaced by a triple-height central orientation hub, while a more accessible entrance has been added to the east of the building.

Working with engineer Atelier Ten and façade consultant Arup, the project took a ‘fabric first’ approach, improving weathertightness and environmental controls and reducing energy demand to save over 600 tonnes of CO₂ a year. Most of the existing materials were re-used or recycled, and The Burrell is the first museum refurb in the UK to achieve a BREEAM Excellent rating.

‘In all,’ concluded the judges, ‘it is an intelligent project with a great level of attention and detail.’ EB

Location Glasgow | Completion October 2021 | Occupation March 2022 | Client Glasgow Life | Main contractor Kier | Engineer David Narro Associates | Services engineer Atelier Ten |  Project cost £30 million (building) | Annual carbon emissions 27.75 kgCO₂/m²/yr | Embodied / whole-life carbon Not assessed | Carbon savings 626 t/CO₂/yr (51%)

Cultural and Religious Building up to £5 million

198 Contemporary Arts & Learning by CarverHaggard

The judges were fulsome in their praise of this radical retrofit and extension, describing it variously as ‘a beautiful approach’ that is ‘super-coherent’, brimming with ‘architectural integrity’ and ‘a real sense of trying to retain the best of the building’.

The scheme provides exemplary new spaces for art, education, and activism; enabling a community group to achieve its long-term vision while preserving its spirit and history. It shows that good design in appropriate materials can deliver significantly lower embodied carbon for a low-cost community building.

A 1960s single-storey concrete building of 200m² was adapted, refurbished and extended with over 400m² of new low-carbon construction. Two new storeys were built directly onto the existing structure in timber frame, with the addition of a new staircase and lift wing on the site of a former extension.

This approach, including the re-use of existing foundations across most of the site, resulted in a 70 per cent saving in embodied carbon against a conventional solution. ‘It has genuinely revitalised an existing building, and it is meaningfully sustainable,’ said the judges. EB

Location London SE24 | Completion July 2021 | Occupation October 2021 | Project cost £1.1 million | Client 198 Contemporary Arts & Learning | Engineer TALL Engineers | Services engineer Max Fordham | Main contractor Dollman Ralston | Annual carbon emissions Not assessed | Embodied / whole-life carbon <200 kgCO₂eq/m² | Sequestered carbon 65 kgCO₂eq/m²

 

Health and Community

The Africa Centre by Freehaus

‘There’s so much joy here – it’s a whole-building approach,’ said the judges about Freehaus’s retrofit of The Africa Centre’s new home. The practice was selected through open competition and the brief called for the transformation of the existing 1960s building to include a café, bar and lounge, gallery, digital learning space and business suite.

Freehaus envisaged what an embassy for the African continent might look like: a space that demonstrates what binds us to one another, while celebrating dynamism. It delivered an extensive engagement programme to help ensure the design served the needs of the community and developed a co-design strategy to provide opportunities for collaborations with designers and makers from the continent and its diaspora.

Foregrounding the existing office building and transforming it into a cultural space meant working closely with the grain of the concrete-framed building. Freehaus chose to showcase the ‘scars’ of the change and embed them into the design. The project promotes fabric-first principles, alongside a series of low and zero-carbon strategies, including super-insulating the building envelope.

The retrofit has turned an unremarkable office building into an iconic cultural institution of genuine community value. As our judges said: ‘It’s stylish and sensitive.’ EB

Location London SE1 | Completion June 2022 | Occupation June 2022 | Project cost £2.6 million | Client The Africa Centre | Engineer Price & Myers | Services engineer OR Consulting | Main contractor QOB Interiors, Tower Demolition | Annual carbon emissions 11.8 kgCO₂/m²/yr | Embodied / whole-life carbon Not assessed

 

Higher Education and Campus

Sponsored by TECHNAL

LSBU Hub by WilkinsonEyre

This radical reworking of London South Bank University’s London Road building to create a more open hub for its Southwark campus was judged ‘very impressive’. ‘A really good approach with excellent data,’ said one judge.

The four-storey 1970s concrete-framed building has a relocated library as its centrepiece, around which sit the university archive, small-group spaces, high-tech teaching spaces, computer labs, study areas and staff offices. New floors are hung from large steel beams that span at roof level, dispensing with the need for new foundations and columns below. ‘The structural aspects were very well thought-through,’ said one judge.

The project also included extensive internal reconfiguration of existing sports and catering facilities and the refurbishment of seven retained lecture theatres, film studios and cinema space. One judge summed it up as ‘a tired old building that has taken off an old jacket and put on a brand new tuxedo’. RGW

Location London SE1 | Completion April 2022 | Occupation September 2022 | Project cost £47.3 million | Client London South Bank University | Engineer Eckersley O’Callaghan | Services engineer BDP | Main contractor Willmott Dixon Interiors | Annual carbon emissions 29 kgCO₂/m²/yr | Embodied / whole-life carbon 375 kgCO₂eq/m²/yr

 

Hotel, Retail and Leisure

Sponsored by Schlüter-Systems

Wraxall Yard by Clementine Blakemore Architects

‘A light, unfussy intervention that pushes the passive measures as much as possible – and it looks beautiful,’ said the judges of this sensitively restored dairy farm in West Dorset.

The brief called for an ambitious renovation that would provide an accessible and sustainable mix of uses without compromising the existing buildings’ unique character. As much of the original building fabric as possible was retained and left exposed. Repairs and alterations used reclaimed materials, alongside naturally derived low-carbon products such as cork and wood fibre insulation. Existing openings were re-used, with expanses of glazing subdivided by timber mullions to filter sunlight and create privacy. Within the courtyard, views are filtered through an informal structure of trees and shrubs. This space is connected to the wider landscape via a boardwalk, where a woodland pasture has been created.

Internally, there are generous wheelchair turning circles, visual contrasts, switches at an accessible height and vibrating fire alarms for the hard-of-hearing. ‘A wonderfully inclusive rural retrofit,’ said the judges. EB

Location Lower Wraxall, Dorset | Completion April 2022 | Occupation June 2022 | Project cost £2.6 million | Client Wraxall Yard CIC | Engineer Structure Workshop | Services engineer Ritchie+Daffin | Main contractor Stonewood Builders | Annual carbon emissions 20.59 kgCO₂/m²/yr | Embodied / whole-life carbon Not assessed

 

House up to £500,000

Bradford Road by CaSA Architects

This ordinary 1930s bungalow in Bradford-on-Avon, Wiltshire, has been transformed into a contemporary, sustainable home that follows Passivhaus design principles. Alterations have been made to the existing property to create light and open living spaces to suit the needs of the client. Sustainability-wise, these improved comfort levels have drastically and successfully reduced energy usage by 90 per cent, from 479 kWh/m² to 47.7 kWh/m².

This was achieved through an excellent working relationship between the client, architect and contractor (who had never worked to Passivhaus principles before) to meet the high levels of airtightness required. Using cost-effective methods such as spray-foam underfloor insulation and high-performance recycled mineral fibre to external timber frame walls – essentially externally insulating to achieve an airtightness of 2.4 m³/hr/m² at 50Pa – meant the architects could retain much of the internal fabric while improving the look and feel of the house. Despite being a ‘commonplace’ project aesthetically, the judges felt it set a precedent.

‘It would have been so easy to demolish and start again,’ they said. FW

Location Bradford-on-Avon | Completion October 2021 | Occupation June 2021 | Project cost Confidential | Client Private | Engineer Mann Williams | Services engineer N/A | Main contractor Top Job Building | Annual carbon emissions Not assessed | Embodied /whole-life carbon Not assessed

 

House £500,000 and over

Hampstead House by Coppin Dockray

The judges enjoyed this winning project. Coppin Dockray has rescued the Trevor Dannatt-designed 1960 Hampstead House from possible demolition, repairing and reworking it as a new family home. Originally designed for an American client with a nod to California’s Case Study houses, Dannatt, an important figure in British Modernism, tucked it into a ‘garden-grab’ site in north London. At one point it almost became lost to its overgrown garden.

The architect has peeled back accumulated 1980s additions to express the original checkerboard pattern of pavilion structures. Contemporary extensions have also been added to create more space and enhance the clarity of the house, while the garden has been replanted with trees placed carefully for solar shading.

Although the judges would have liked to have seen the project pushed even further in terms of its sustainability, such as going electric, they deemed the project sensitive, respectful, and ‘ungreedy’. ‘They haven’t lost the sense of place,’ they concluded. FW

Location London NW3 | Completion May 2022 | Occupation May 2022 | Project cost Confidential | Client Private | Engineer Structural Design Studio | Services engineer Jones King | Main contractor Sherlock London | Annual carbon emissions 25.05 kgCO₂/m²/yr | Embodied / whole-life carbon Not assessed | Carbon savings 35.71 kgCO₂/m²/yr (58.7%)

Housing

Park Hill Phase 2 by Mikhail Riches

‘This project fulfils a lot of objectives’ praised the judges. ‘There’s both a strong embodied carbon and social story,’ they added.

Phase 2 of the redevelopment of the high-profile Brutalist estate in Sheffield, Park Hill is more modest and ‘subtle’ than its Stirling-nominated first – completed nearly 10 years ago by Hawkins\Brown and Studio Egret West. The light-touch approach undertaken by Mikhail Riches included insulating the existing brickwork internally and cleaning it externally, using hygrothermal risk analysis of the wall build-up to determine optimal thermal improvement while mitigating moisture risk – a technique which the judges described as ‘exemplary’.

Taking lessons from Phase 1 and speaking with residents, the ‘streets in the sky’ have been celebrated by bringing new life back to them to restore a sense of community – putting occupants at the forefront of decision-making.

The judges deemed 107 Niddrie Road deserving of praise too for the way it deals with environmental condition: they thought the project pushed this as far as it could go, turning a draughty leaky building into something thermally performing on an incredibly low budget. ‘It’s incredibly valuable and could inspire the industry further’, they said.

However, ‘in the round, Park Hill Phase 2 is a clear winner’, the judges said. ‘A lot sets it apart from the rest, including scale and occupant perspective.’ FW

Location Sheffield | Completion August 2022 | Occupation December 2021 | Project cost Undisclosed | Client Urban Splash | Engineer Civic Engineers | Services engineer Beechfield Consulting Engineers | Main contractor Urban Splash Construct | Annual carbon emissions 20 kgCO2/m²/yr | Embodied / whole-life carbon 360 kgCO2eq/m² | Carbon savings 131 kgCO2/m²/yr (87%) | Carbon emissions (all) 57 kgCO2/m²

 

Listed Building up to £5 million

Seven Sisters Country Park by Pritchard Architecture

This £1.9 million project was praised for being ‘modest and strong’ and as ‘extraordinarily good value’ by judges. It involved the extensive upgrade and improvement of visitor facilities at a 280-hectare country park that incorporates chalk cliffs, a meandering river valley and open chalk grassland at the mouth of River Cuckmere, between Seaford and Eastbourne.

The project focused on the rework and environmental upgrade of the main visitor hub based in a historic farmstead set around courtyard spaces. This involved repurposing existing buildings, including the deep retrofit of three listed buildings, to provide a new visitor centre, café and toilets, which judges praised as ‘giving a campus feeling to the whole’. The retrofit included new insulated walls, roofs, ground floors and thermally efficient glazing. Timber and sheep’s wool linings were built as independent structures, for ease of future deconstruction, with a ventilated void inserted between the existing fabric and new insulated linings to manage moisture. The judges commented on the ‘impressive operational performance’ and summed up: ‘This is a modest project but very impactful locally.’ RGW

Location Seaford | Completion July 2022 | Occupation July 2022 | Project cost £1.9 million | Client South Downs National Park Authority | Engineer Marbas | Services engineer B F Keane | Main contractor Baxall Construction | Annual carbon emissions 4,761 kgCO₂/yr (whole project) | Embodied / whole-life carbon 186 kgCO₂eq/m² (dairy barn), 40 kgCO₂eq/m² (café) | Carbon savings 75-90%

Listed Building £5 million and over

Sponsored by Selectaglaze

Park Hill Phase 2 by Mikhail Riches

Judges praised the scale of transform­ation in this environmental upgrade of one faceted section of the brutalist Grade II*-listed building, built between 1957 and 1961 as council housing, and which provides 195 flats and 2,000m² of new commercial space.

Originally designed by architects Ivor Smith and Jack Lynn, and famous for its ‘streets in the sky’ typology and gridded concrete structure, significant fabric upgrades were needed to mitigate the original building’s thermal bridging and improve energy efficiency. This saw annual operational emissions reduced from 151 to 20 kgCO₂/m² with whole life embodied carbon calculated at 360 kgCO₂eq/m² compared with a new build equivalent of 800 kgCO₂eq/m².

Judges were impressed by how the scheme had ‘clearly taken learnings from Phase 1’ and by its ‘innovation and transformation in civic terms’. ‘We have to deal with our 60s buildings’, said one, ‘and this says these things are possible.’  RGW

Location  Sheffield | Completion August 2022 | Occupation From December 2021 | Project cost Undisclosed | Client Urban Splash | Engineer Civic Engineers | Services engineer Beechfield Consulting Engineers | Main contractor Urban Splash Construct | Annual carbon emissions 20 kgCO₂/m²/yr | Embodied / whole-life carbon 360 kgCO₂eq/m2 | Carbon savings 131 kgCO₂/m²/yr (87%) | Carbon emissions (all) 57 kgCO₂/m²

 

Schools and Further Education

Houlton School – Retrofit of Rugby Radio Station by van Heyningen and Haward Architects

‘A wonderful transformation done with intelligence and sensitivity’ was one judge’s comments on this new 6FE + 6th Form secondary school. Built to serve a new community in Rugby of 6,200 homes on the site of the former Rugby Radio Station, it was formed in part out of the creative adaption of the listed 1926 transmitter building, which, together with three new buildings, open spaces and playing fields, forms a coherent school campus. The restoration and repurposing of the historic building as an integral part of the school was praised for the ‘sheer panache in its intervention’.

Works included repairing and repointing the façades to shed water, adding internal wall insulation (IWI), insulating the ground floors and roofs, replacing historic windows with high performance replicas and creating an effective air barrier throughout. The IWI has a lime plaster parge coat to provide the air barrier and wood-fibre insulation boards, creating a void-less and vapour-open lining that prevents moisture damage to the historic fabric.

‘It has transformed an unused listed building into a useable new school. Amazing,’ was one judge’s summary. RGW

Location Houlton, Rugby | Completion August 2021 | Occupation September 2021 | Project cost £39 million | Client Urban&Civic/Aviva Investors (joint venture) | Engineer Price & Myers | Services engineer Hoare Lea | Main contractor Morgan Sindall Construction | Annual carbon emissions 8.1 kgCO₂/yr (retrofitted buildings) | Embodied /whole-life carbon 404.8 kgCO₂eq/m² (retrofitted buildings)

 

Workplace up to £5 million

Bloqs – Meridian Works Open Access Factory by 5th Studio

Bloqs, which provides makers with low-cost workspace and equipment as part of north London’s Meridian Water regeneration programme, won after impressing judges with its social and collaborative design approach and its contextual and ‘Continental’ flavour.

This hangar-like building – designed in close collaboration with client Bloqs – provides a huge array of facilities within 3,000m² of workspace, a combination of new build and the adaptive re-use of a former vehicle-testing facility. One judge said: ‘It’s rather international in its approach. When we have to solve a lot of questions regarding how to make a denser, more urban environment out of brownfield land or leftover areas, it’s important not to disregard what’s already there.’ WH

Location London N18 | Completion September 2021 | Occupation October 2021 | Project cost £2.36 million | Client Bloqs | Engineer Arup | Services engineer Arup | Main contractor Ashe Construction | Annual carbon emissions 8.47 kgCO₂/m² | Embodied / whole-life carbon Not supplied

 

Workplace £5-10 million

98-100 De Beauvoir Road by Henley Halebrown

This ‘elegant’ low-carbon retrofit by Henley Halebrown retains large quantities of the brickwork, timber floors, cast iron and concrete found in the existing pair of connected Edwardian industrial buildings in De Beauvoir Town, Hackney.

The architect has reimagined space and circulation both inside and out and the resulting workplace provides studios for small businesses, which can be let to a single occupant or on a floor-by-floor, multi-let basis. Many of the original Edwardian features have been retained or restored, such as the traditional yellow London stock brickwork, large steel-framed windows and original details on the walls while a new storey has been added to both buildings, each with its own character and design resolution.

Judges praised the scheme’s ‘sophisticated’ architecture and said it had ‘ticked all the boxes’. They also pointed out that Henley Halebrown had won the same category in last year’s Retrofit Awards with The Laszlo. ‘They clearly have this typology down to a tee. This mastery they have is really impressive,’ one judge remarked. WH

Location London N1 | Completion March 2022 | Occupation November 2022 | Project cost Undisclosed | Client The Benyon Estate | Engineer Parmarbrook | Services engineer AJ Energy | Main contractor Sullivan Brothers | Annual carbon emissions Not supplied | Embodied / whole-life carbon Not supplied

 

Workplace £10 million and over

The Gramophone Works by Studio RHE

On the edge of the Grand Union Canal in London’s Kensal Rise lies an exciting new office block that had a former life as a wallpaper factory. Redeveloping this sturdy two-storey concrete building with a history dating back 100 years, Studio RHE, engineer Heyne Tillett Steel and client Resolution Property made extensive use of CLT to extend upwards to six storeys while adding elements including a landscaped link between the canal and Kensal Road and bike parking.

Calling it ‘transformative’, the judges praised the project’s commitment to whole-life carbon design and ‘imaginative’ use of space, light and materiality, including the juxtaposition of new timber and old concrete. One judge commented: ‘I really liked the fact the structure was exposed and not masked in any form or shape.’ WH

Location London W10 | Completion February 2022 | Occupation February 2023 | Project cost £25 million | Client Resolution Property | Engineer Heyne Tillett Steel | Services engineer Atelier Ten | Main contractor Graham Construction | Annual carbon emissions 17.01 kgCO₂/yr | Embodied /whole-life carbon 127 kgCO₂eq/m²

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