May 16, 2020

From the UK to Hong Kong: Talking retrofitting and restoration with Purcell

uk construction
Dan Brightmore
8 min
Battersea Power Station
Purcell has more than 70 years of experience in architecture, master planning and heritage consultancy across a diverse range of retrofitting and regene...

Purcell has more than 70 years of experience in architecture, master planning and heritage consultancy across a diverse range of retrofitting and regeneration projects. The company’s portfolio boasts the restoration and transformation of listed buildings and heritage assets, including significant UK icons such as the Palace of Westminster and Canterbury Cathedral. Purcell’s skills have also been harnessed with cutting edge new builds and exemplar sustainable solutions. This spectrum of expertise has also been transferred overseas to the company’s offices in Hong Kong and Australia.

Jeremy Blake, a Senior Partner at Purcell, explains the practice is known for working on heritage projects which need a careful and faithful conservation/restoration thrust, such as the Leighton House Museum in Kensington which won a Europa Nostra award. “We also go into heritage assets that need a new lease of life, potentially through their transformation, public accessibility or even a change of use. To that end, we’re involved with the restoration of Battersea Power Station,” reveals Blake “On a number of key projects like this we find they’ve become tired, not only in the condition of the fabric, but also in their engagement with their existing use – public or private.”

Purcell’s work is inextricably linked to sustainability, though Blake remembers much scepticism in the industry around early developments in this area. “What’s happened since, particularly when oil prices surged, is the dawn of a commercial reality because of the genuine economic savings that can be achieved through responsible sustainability,” he says. Paradoxically, Blake notes a phenomenon in the industry of what he calls ‘eco-bling’ or ‘green-wash’, where projects are not as sustainable as claimed. “There’s a tendency for architects to focus on energy and water conservation, rather than examining the thermal performance of the building envelope beforehand.”


Blake also highlights the current alignment of BREEAM (Building Research Establishment Environmental Assessment Method), the world’s leading sustainability assessment method for master planning projects, with LEED (Leadership in Energy and Environmental Design), a green building rating system. “Historically they’ve been two competing sustainable criteria which may become a singular international standard,” he says, adding that because his clients have become far more hands on and savvy about the advantages of sustainability, there have been alternative measures introduced to the industry such as EDGE (Excellence in Design for Greater Efficiencies), the green buildings certification. “That has a much simpler, end-user set of tools which can be applied to see where you get your benefits and savings in three key areas: energy, water and the embedded energy in materials. Hoteliers we work with are using that tool rather than BREEAM or LEED as it is more responsive to their sector.” Blake notes a definite shift with sustainability certification also offering a commercial benefit: “On many client briefs one of the first requirements is that a project has to be BREEAM excellent or outstanding. There are two aspects to sustainability: the enduring properties of our built heritage and the environmental issues prevalent in modern discourse.”

To deliver those requirements, Purcell is embracing innovation and leveraging new technologies. “We’ve been implementing drone measured surveys,” says Blake. “We used this approach on the central tower of Durham Cathedral which meant we didn’t have to pay for scaffolding – it was the first time a drone survey had been used in that way.” These drone surveys are used in Point Cloud where Purcell generates 3D models of measured surveys with laser scanners. “The degree of information we’re now able to secure from drone surveys without a visually intrusive, potentially damaging and costly physical infrastructure like scaffolding gives us a very up-to-date and close picture from which we can develop useful base information for conservation, retrofitting and intervention.”

Purcell is also using augmented reality to transpose proposals onto a pair of goggles to stand a client in their existing building and show them the transformation. “It allows our clients to be bold with their choices and more positive about decision-making with their plans,” reflects Blake. “It enables the client to see the exact graphical representation of our proposal, enhancing the possibilities for positive retrofitting.”

Among key partnerships, Purcell also collaborates with other practices and is currently working with the National Trust at Clandon Park. “We’ve previously worked collaboratively with Allies and Morrison (A&M) on the conversion of Arsenal’s football ground (a historic listed building) into residential,” adds Blake. “The National Trust approached us once A&M won the limited competition to work with them on the proposals (for Clandon Park). We’ve also worked with Herzog & de Meuron in Hong Kong and partnered with them on the Flinders Street Station in Melbourne which is how we established our office there.” Purcell is also on the board of the AABC (Architects Accredited in Building Conservation) and engages positively with bodies like the UK Green Building Council. Meanwhile, through its heritage consultancy, the practice is providing CPD support (Continuing Professional Development) for the RIBA on their programme of new into old.

Blake believes retrofitting needs to be approached with sensitivity by the industry because there is a tendency to jump to conclusions about how aspects of a building can be harnessed without fully appraising the built asset they’re starting with. “This is where the ‘green-wash’ and ‘eco-bling’ comes in,” says Blake ruefully. “It’s like a box of tricks that can be added universally without looking specifically at the inherent strengths and weaknesses of the building. For example, solid masonry walls, if dry and kept at the appropriate temperature internally, are incredibly thermally efficient. So, if you can address why it’s damp and not thermally efficient, rather than just fully lining and insulating out, you can achieve a softer approach towards getting a building working environmentally and responsibly without a heavy-handed restoration.”

Blake recognises it’s a challenge in a climate where there is a controversial debate about the validity of u-values (a measurement of how effective a material is as an insulator) in assessing thermal efficiency of buildings, when thermal imaging is beginning to expose that u-value criteria is not always delivering the built solution that was promised on paper. “The thermal performance of a wall needs to be looked at in a different way than just a simple mathematical sum of individual components with test bed u-values. Thermal imaging has shown that what, based on design, should be blue, is significantly scarlet and leaking energy. Other building methods which, on paper, appear not to have the same thermal efficiency, when tested via thermal imaging, are proved to be more thermally efficient than what modern materials and u-values would show,” adds Blake.

With 12 offices across the UK and three overseas, Purcell is both international and local with a spectrum of engagement from ancient monuments right through to cutting edge new build technology. “We are bespoke and innovative in that regard, across a range of architecture where we continue to win awards as experts in the field. We’re both passionate and committed while remaining responsive to the operational and aspirational requirements of our clients,” asserts Blake, who is proud of Purcell’s National Portrait Gallery appointment to work with Jamie Fobert on the proposals for refurbishment and extension of the Grade I listed building.

In parallel, Purcell has been tasked with creating a home for a different kind of modern icon at Aerospace Bristol, for Concorde. Elsewhere, Purcell has worked on the Metropolitan Cathedral of Liverpool – the Frederick Gibbard structure needed significant conservation and restoration advice – while other iconic buildings in northwest England benefitting from its advice include Manchester Town Hall. “Overseas, we’re working on a project in Hong Kong,” adds Blake. “It’s one of 16 buildings that remain of the historical core followings years of redevelopment. We’re retrofitting and transforming those buildings into an arts hub featuring a gallery, auditorium and ten restaurants.”

Purcell’s expertise has also been brought into the Battersea Power Station project. “We’re aiming to minimise intervention while consolidating and conserving an iconic national landmark,” says Blake. “An unusual period and content, it includes a variety of artefacts internally along with the switchgear room. It’s not just the chimneys – which, ironically, had to come down and be replaced – but all the brickwork.”

Blake predicts that retrofitting and restoration projects like these, with sustainability in their heart, are an unsung growth market. “Around 85% of our building stock is more than five years old. In time it will all need consideration of retrofitting which creates all sorts of opportunities with regeneration and renewal projects in our towns and cities,” he notes. “Beyond that, if you look at the rejuvenation that’s now being encouraged in the UK’s seaside resorts and market towns, it contributes to how our communities are being transformed, which is related to urban renewal and can come on the back of infrastructure and transport hubs. You see it when you look at the impact of the Elizabeth line in London and trams in cities like Manchester and Edinburgh. Areas that were in serious social decline are becoming very attractive for inward investment and regeneration. Often, that investment immediately goes into restoration and retrofitting to bring tired building fabric into 21st century usage.”

Looking ahead, Blake is keen for Purcell to further develop and orchestrate its technical skills while reaching out to stakeholders and developing frameworks. “We’ve just embarked upon a strategic alliance with Oracle software and we’re looking to do our first project retrofitting a building with them in Ireland,” he reveals. “We’re not complacent with our own pedigree, heritage and skillset – we want to expand, consolidate and grow into new areas.”

Share article

May 11, 2021

The Queen's Speech and its impact on construction

Dominic Ellis
4 min
With bills covering infrastructure, planning and building safety the implications for the UK construction industry are broad
With bills covering infrastructure, planning and building safety the implications for the UK construction industry are broad...

As the UK strives to bounce back after the pandemic and 'level up' opportunities across the country, today's Queen's Speech had much for the construction industry to digest, as a total of 31 bills were presented to parliament.

From infrastructure and planning (first unveiled last August), to ongoing building reforms and 'skills for jobs' to promote lifelong learning, the bills' implications are broad. Among the notable developments:

  • The White Paper Planning for the Future (unveiled in August 2020) proposes wide-ranging reform, arguing that the planning system in England was “outdated and ineffective”
  • A bill covering ground rents on future lease agreements will “set future ground rents to zero" in the forthcoming 2021-22 session 
  • A Product Security and Telecommunications Infrastructure Bill will extend 5G mobile coverage and introduce new safety standards for digital devices
  • A Subsidy Control Bill for supporting private companies, now the UK has left the EU's "state aid" regime
  • The Procurement Bill will replace EU rules on how the government buys services from the private sector
  • Tax breaks for employers based in eight freeports to be set up in England later this year will be included in a National Insurance Contributions Bill
  • A new UK agency to search for ground-breaking scientific discoveries will be established by the Advanced Research and Invention Agency Bill
  • New powers to build and operate the next stage of the HS2 high-speed rail line are contained in the High Speed Rail (Crewe-Manchester) Bill

Chairman of Strawberry Star, Santhosh Gowda, said modernising the UK's time-honoured planning laws was never going to be easy, but the idea of a "dynamic, flexible and digitalised system" is an exciting prospect. "It will be a balancing act to boost housing supply without compromising on design, community, and ecology, whilst also ensuring it fits with the government’s ‘Building Better Building Beautiful’ ethos too," he said.

Marnix Elsenaar, Partner and Head of Planning at Addleshaw Goddard, said after months of rumours that the Government had got 'cold feet' about following through on the more controversial proposals in its Planning White Paper, today's Queen's Speech has promised a Planning Bill to "modernise the planning system, so that more homes can be built", but we await more details.

"The Bill is likely to require local authorities to allocate land either for growth, so that new homes, schools, offices and shops will get a fast-track to planning approval, or for protection," he said. "Rumour has it that a third "regeneration" zone is being considered. Whether other elements of the White Paper, such as a new infrastructure levy will make their way into the Bill remains to be seen. What we can say with certainty is that the Bill will be a big step on the road away from the development control system that we're used to, towards a US-style zonal system that front-loads community engagement to the plan-making stage and provides a national and local design code that sets the parameters for what you can build."

Ben Dyer, CEO of Powered Now, a field service management software working with over 1,500 SMEs in the trades, wants to see a simple rules-based approach rather than the decision of a committee, therefore resulting in a faster decision and appeal process. "We believe it should be a requirement that all county councils should have a clear housing and development policy. This will increase the transparency on what can, and can't be built and will save a lot of time, effort and money. This policy should focus on protecting green spaces by relaxing planning rules on brownfield land," he said. 

Plans should include simpler planning for the renovation of existing buildings, and relax the rules for homeowners who want to improve their houses, he added. 

"There is an opportunity for the Government to make a concerted effort on the aesthetic of homebuilding, that has been sorely ignored on a national level for so long. A carrot and stick approach that rewards developers for building outstanding and unique buildings, while penalising generic out of character developments would be hugely welcome," he said. 

"Following the collapse of the Green Homes Grant, this plan should also include new buildings to be developed with energy production and efficiency at the heart of the design process. This is absolutely essential if the UK is to hit net zero carbon emissions by 2050."

Timothy Douglas, Policy and Campaigns Manager, Propertymark, said the announcement in today's Queen's Speech that the UK Government will publish a Renters Reform White Paper in the Autumn demonstrates that Ministers are prepared to engage with the industry to understand the impact any substantial legislative changes will have on those involved in the private rented sector.

“With the focus of the new package on lifetime deposits, landlord redress and greater enforcement, the UK Government must look at ensuring that a system that would allow deposits to be passported can only take place if there is a bridging loan, with the UK Government as the guarantor, in order to ensure the remaining part of the deposit is covered should the tenant default," he said. "Additionally, the UK Government must prevent ‘double jeopardy’ and only extend redress membership to properties that are fully managed."

He said Propertymark will be engaging with MHCLG and MPs to ensure they fully understand the consequences of any changes, and scrutinising the White Paper and proposed legislation, to ensure the best possible outcome for members.

Share article