London Fire Brigade has raised concerns over the safety of an underground bus garage proposed as part of a major regeneration scheme.

Plans to demolish Edgware's existing bus garage and create an underground facility for electric vehicles have been drawn up by developer Ballymore and Transport for London (TfL) as part of a development set to provide 3,365 homes and 463 student flats.

Campaigners have previously likened the safety of the scheme to “building a volcano” underneath the flats, which would be constructed on the site of the Broadwalk Centre and surrounding land.

There have been cases of electric buses catching fire, and campaigners fear a “thermal runaway” could create an uncontrollable blaze. The developer says electric vehicles will not be permitted unless the design has been approved by London Fire Brigade (LFB), Barnet Council, Health and Safety Executive, and Building Control.

A letter obtained by Save Our Edgware campaigners via a Freedom of Information request reveals LFB “is not satisfied with the proposals” for the bus garage.

LFB’s design engineering group states that the scheme’s design team has approached the garage “in the same way as a conventional car park”, failing to “address the specific hazards posed by alternative fuel vehicles in this environment”.

It adds: “Especially, it has not been recognised that, like some other emerging technologies, the electric vehicle (EV) industry lacks sufficient published fire safety research to determine if the widespread use of EVs (and especially large goods and passenger EVs) is compatible with current UK fire safety regulations and guidance.”

The design engineering group calls for “robust and evidenced research” to ensure any fire safety recommendations “are adequate to mitigate the unique risks introduced by this emerging technology”.

It adds that the design team is currently “severely underestimating the fire loading and unique difficulties posed by electric vehicle fires generally and a large number of electric buses in particular”.

In the same letter, the LFB’s transport liaison group comments that the project “is not feasible as laid out in the proposals supplied”.

It warns that the close proximity of buses could impede the movement of firefighters and limit the effectiveness of their operations.

The liaison group questions whether any sprinkler system could be designed to suppress or control an electric bus fire with a lithium-ion battery pack undergoing thermal runaway, and recommends exploring other means of fire suppression.

It adds that because of the characteristics of lithium-ion battery fires “suppression or firefighting extinguishing media may need to be applied for hours or days, with local supply and environmental waste implications”.

Although the letter is dated November 30, 2022, LFB confirmed its position has not changed, although it added that it remains in dialogue with TfL about the proposal.

A spokesperson for the development said: “The safety of our residents and all users of our developments is of paramount importance to us. The letter in question dates from 2022 and since then we have had an ongoing dialogue with London Fire Brigade and other stakeholders and we are continuing to develop our proposals in response to feedback.

“The garage will not be operational until 2030 at the earliest and we are clear that no electric vehicles will be permitted unless the design has been approved by the London Fire Brigade, Barnet Council, the Health and Safety Executive and Building Control.

“We will continue to work closely with relevant authorities, battery and bus manufacturers to ensure the proposal is designed and built to the highest fire safety standards, with fully tested safety measures undertaken by a UK accredited testing house.”