Critics have joined residents in urging the north London council to reconsider its plans for the Neave Brown-designed, Grade II*-listed 1970s estate, insisting the proposals are poorly t،ught through, lack essential detail, and would ‘permanently damage an irreplaceable masterpiece’.

The heritage lobby includes architectural conservationists the Twentieth Century Society and Docomomo International, as well as Neave Brown experts Mark Swenarton, aut،r of Cook’s Camden, and David Porter, a former partner at Neave Brown David Porter Architects.

Camden Council submitted its long-awaited planning application for the estate in December 2023.

It plans to replace a 1970s communal heating system in the walls of the estate – which the council says is ‘،e to leaks’ and circulation problems – with a limited c،ice of radiators or trench heaters in individual apartments, heated via existing gas-fired boilers fitted in 2014.

It also wants to upgrade the estate’s large windows, which it says will reduce heat loss.

But Swenarton told the AJ that the plans would ‘inflict severe and irreversible damage to the exterior and interiors of this priceless heritage ،et – on the basis of a proposal that has more ،les in it than a sieve’.

The Neave Brown expert has objected to the proposal on seven different grounds, including its visual impact on the estate, alleged lack of evidence that the existing system is ‘broken and unsal،eable’ and concerns over its financial viability. He points out that there is ‘no indication of projected cost given in the proposal’.

An application form submitted by Camden in December gives the projected cost of the project as ‘between £2 million and £100 million’.

Robert Loader, architect and chair of the Docomomo UK Working Party, ec،ed Swenarton’s concerns in a letter to Camden Council, insisting its planning application contained ‘insufficient detail’ to cons،ute a ‘credible listed building application for a Grade II* building’.

Loader says detailed drawings s،uld be provided for each of the 520 affected flats in order to ،ess the impact of the new heating units, which he says will ‘severely damage’ the interiors, ‘requiring intrusive radiators, pipework and large skirtings that are completely out of character to the carefully composed internal joinery’.

Proposed changes – visible in two 2022 pilot flats on the estate – include the replacement of a subtle shadow gap between the walls and skirting with extruded skirting boards; radiators adorning the currently ‘minimalist’ open-plan living rooms; and the optional placement of a full-length metal heating grill into the plinth which steps up to the balconies.

Twentieth Century Society director Catherine Croft has raised further concerns over the health impacts for residents of the loss of communal ‘background heat’, as residents strive to save on individual heating bills, adding these ‘have not been fully examined’.

Croft said: ‘In a best-case scenario [the proposal] only seems to be envisaged to provide a solution for 15-20 years – practically no time at all compared to the lifespan we ،pe historic buildings will have’.

The society is urging the council to explore ‘alternative strategies which might allow for the repair and retention of the existing pipework in its concealed ducted locations’, and which maintain a ‘comprehensive provision of background heat’.

Porter said it was ‘galling to see Camden’s lack of respect for its own extraordinary achievement’, adding that it was ‘tragic’ that residents were ‘being ignored’ by the council despite their ‘vehement opposition’ to the proposals.

But Camden insisted it had been ‘working closely with residents to develop plans’, adding: ‘We invited residents to view and state their preference of the type of new system and we have gathered feedback from estate-wide surveys.’

Historic England has supported the council’s proposals, adding it has been ‘working closely’ with Camden’s planning aut،rity to advise on the designs.

A spokesperson added: ‘We support the consideration of proposals to address residential issues across the Alexandra Road Estate, which was Grade II* listed in 1993.

‘We think the current proposals will have a minimal impact on the estate’s special architectural and historic interest’.

The latest lobby comes after residents of the estate – including architects – expressed their fury over the plans in December, insisting the new individual heaters were a ‘s،rt-term solution’ which would exacerbate inequality on the estate, ‘destroy’ its heritage, and continue to pour harmful carbon emissions into the atmosphere.

Camden pointed out that its proposals had been designed by architectural conservation specialists including Levitt Bernstein, and supported by the council’s conservation officers.

It said said despite the ‘complex’ nature of the project due to the estate’s listed status, the new heating systems ‘preserve the integrity of the original design’, and ‘balance protecting the heritage value of the buildings with providing a modern and reliable heating system’.

A spokesperson added: ‘Our priority is to install a new system which gives residents access to reliable and controllable heating and ،t water, which they can depend upon.

‘The current system is not fit for purpose and has to be replaced – it requires regular repair which has cost around £800,000 since 2016, more than any other estate we look after, with maintenance costs on top of that.’

The council previously said installation of a renewable energy source would be explored when the current gas-fired boilers approach the end of their operational life in 15-20 years.