Has the climate emergency tipped the balance in favour of upgrading rather than demolishing the UK’s ageing tower blocks? Ella Jessel reports
‘Retrofit is quite expensive but it’s still the right thing to do,’ says Sarah Cary, executive director of place at Enfield Council, summing up the dilemma faced by the owners of the UK’s tired high-rise blocks.
Speaking at a panel discussion on the climate crisis organised by Public Practice, Cary explains how the north London borough is undertaking a variety of retrofit projects.
In 2018 it completed the installation of heat pumps to 400 flats in eight tower blocks, the largest district ground source system in England. It is now undertaking a retrofit pilot on four of its 54 tower blocks.
‘The worst one of those is costing £8 million and the cheapest is about £4 million,’ Cary says, adding: ‘It means we can’t [fund] other things and we might end up doing less housing development.’
Pivotal decisions like this are being made across the country as the estimated 400,000 high-rise flats built during the 1960s and 70s building boom reach the end of their design life.
Faced with poor building fabric and cold bridging, today’s residents are reportedly suffering from acute fuel poverty. Yet these blocks often require major repairs to bring them up to standard.
What’s more, the significant cost of refurbishment means upgrades are often delayed until a decision can be taken over whether it would be easier and cheaper to simply demolish and rebuild.
The stakes are especially high for local authorities, which are often too cash-strapped to afford borough-wide retrofit programmes.
By reworking what we already have we can save money and save communities in the process
But with councils across the country declaring climate emergencies, housing chiefs are coming under greater pressure to take a longer-term view and avoid the heavy carbon costs of demolishing concrete towers.
This is further complicated by the fact that tower block refurbishment projects – especially those aiming to insulate a building’s fabric – remain under huge scrutiny in the wake of 2017’s Grenfell fire.
Since the blaze, which killed 72 people, campaigners have been calling for immediate improvements to tower blocks, such as installing sprinklers in all high-rises and the removal of flammable cladding.
When buildings are structurally safe and able to be refurbished, the benefits of retention over demolition are clear. As Jonathan Tuckey of Jonathan Tuckey design says: ‘Existing communities have to be relocated when destroying towers, which is both expensive and hugely damaging to social cohesion. By reworking what we already have we can save money and save communities in the process.’
In addition, as Dustin Benton, policy director at think tank Green Alliance, explains, the amount of embodied carbon in a tower block means it is more environmentally friendly to retain it. ‘If we want to get to net zero we can’t tear everything down and rebuild it,’ he says.
But are these environmental arguments gaining any traction among local authorities? ‘People are still scrambling around for little bits of money in the short term rather than thinking of a local-authority-wide retrofit scheme,’ says Benton. But he believes the recent spate of councils declaring climate emergencies is a cause for optimism.
Balfron tower © the modern house
Enfield declared a climate emergency in June. Yet as Cary, a former head of sustainability at British Land, points out, while cost-effective in the long term, the upfront costs of retrofit are high. ‘There are very few financial incentives to do major retrofit, particularly if you have to move all the residents out,’ she says.
She adds that many of the council blocks built in the 60s and 70s had to be demolished. ‘There are some buildings that were very badly designed, whether [in terms of] social issues or the structural fabric, and they do have to come down.’
This has proved the case with scores of tower blocks built using the large panel system – the method deployed at Ronan Point – many of which have been found to be at risk of collapse. Many problems were revealed after councils inspected their stock in the wake of the Grenfell fire.
Buckley Gray Yeoman director Laura O’Hagan admits reuse is not always the right answer, though each building should be looked at individually. ‘Tower blocks should be assessed on their merits,’ she says, ‘but if the frame of a building is structurally sound and offers sufficient floor-to-ceiling heights then this makes a strong case for its retention.’
The practical challenges of upgrading tower blocks include considering the thermal values of a building’s existing envelope as well as its space standards, heating and ventilation and any asbestos removal.
Simon Bayliss of HTA Design has experience of both retrofit work – the practice has refurbished around a dozen high-rise blocks across London – as well as demolishing and starting again.
From what he has found, floor-to-ceiling heights are often broadly in line with current standards while space standards are typically Parker Morris and a little under current benchmarks.
If the building frame is structurally sound and offers sufficient floor-to-ceiling heights then this makes a strong case for its retention
‘Refurbishment is often messy and difficult to manage well as individual conditions vary widely across any particular building,’ he says, ‘and the largely subcontracted nature of much of current construction makes management and oversight very difficult and as a result usually more costly.’
Bayliss also argues that in the aftermath of Grenfell, there are new challenges in terms of the lack of clarity in the regulatory environment. ‘Most blocks remain in the ownership of local authorities, who are often not well equipped to manage construction contracts and balance the need to minimise capital expenditure against the benefit of long-term savings,’ he says.
O’Hagan says the sheer cost of undertaking some of these challenges means demolition often becomes the most attractive option. ‘To successfully encourage more widespread refurbishment rather than demolition of these buildings therefore requires some form of inducement,’ she argues.
Possible incentives, she suggests, could comprise zero VAT rating on refurbishments (currently charged at 20 per cent) or an alternative listing system for the embodied carbon in a building.
‘This could result in their remodelling and reuse in a similar way to buildings that have been listed for their historic value,’ she says.
While retrofitting tower blocks can often avoid displacing residents, as O’Hagan points out, refurb does not necessarily mean a guarantee of stability for existing tenants.
There have been notable cases, such as Balfron Tower in east London, where residents were decanted and the flats upgraded to be sold off on the open market.
It is vital that people who live in the buildings are central to the refurb process, argues Gibson Thornley Architects director Matt Thornley. ‘The people who live in tower blocks know a huge amount about how their buildings work and don’t work. Time is needed up front with residents to work out what the issues are, what are the priorities and to create a project-specific strategy.’
Danielle Gregory is a resident of the Ledbury Estate, which was evacuated in August 2017 amid safety concerns, and a member of campaign group Tower Blocks UK. She agrees that residents should always be central to the retrofit process.
‘If landlords continue to see the buildings and the residents who inhabit them as entirely separate,’ she says, ‘then these issues won’t be resolved any time soon.’
Tony Barton, chairman of Donald Insall Associates
The challenges for reusing tall buildings of some architectural merit are no different in principle, than any other large building seeking a new life. We believe that we should be talking about “futureproofing” tall buildings as “retrofitting” doesn’t describe the complex issues involved. For example, a key point to consider in a tall building is safe escape in case of fire, including safe escape for all levels of mobility. If a tall building doesn’t have a second stair and protected lift shaft, can one be accommodated, inside or out, in such a way as the significance of the architecture is not lost?
Large structures can be adapted to meet the needs of today and tomorrow without damaging character, through the creative attention of the architectural profession.
The embedded energy within the existing fabric will be significant and must be accounted for when considering futureproofing or replacement. What is the cost in cash and carbon? Would a new use offer attractive and comfortable amenity? Can it be serviced and will the heating/cooling result in unsustainable energy use?
Deborah Saunt of DSDHA
Existing preconceptions by clients and agents [on retrofitting tired office blocvs] about what will and won’t work makes retrofit harder as you are often dealing with a ‘cookie cutter’ solution of standard spatial components, which tend to be used as a benchmark for making assessments. This means that, as an architect, you need to be fully conversant in what the standard economics of the industry are to offer new creative solutions which challenge them.
The best way of dislodging the more entrenched preconceptions of commercial space, with its expectations of certain minimum floor to ceiling heights, column spacing etc, is to provide evidence for a viable alternative, and that means using research and business intelligence as key tool. Key to this is in providing precedent studies, including the performance statistics of other projects – not just spatially, but also in terms of economic and environmental performance over a longer period than usual.
It is becoming easier to shift expectations using visualisation tools, such as AR, to show how new spaces and amenities can push the design. At our scheme to retrofit and extend 125 Shaftesbury Avenue we used AR to demonstrate to our client Almacantar that, whilst providing terraces on every floor would lose some floor area, it would also bring tangible benefits. This hands-on, forward thinking approach is key in terms of promoting new qualities of space that challenge conventional wisdom