Construction starts on more than 800 high-rise residential new-build and upgrade projects are being blocked by Building Safety Regulator design checks.

Frustrated developers warn the logjam in sign-offs to start building is now threatening to undermine the Government’s housing delivery and growth drive.

According to latest figures obtained from a Freedom of Information request from consultant Project4 over 90 major new-build projects are stuck in a bottleneck awaiting Gateway 2 design approval to start work.

Just 11 new-build jobs are reported to have cleared Gateway 2 checks, although only two of these are understood to have passed through the present checking regime.

The delays are also holding up retrofit works on over 600 existing High Risk Buildings (HRB) classified as over seven storeys or 18m.

The Building Safety Regulator (BSR) has come under fire for wasting time, increasing costs, and stalling important projects.

Developers complain they are having to grapple with unclear submission requirements, limited pre-submission consultation, and poor communication.

One developer told the Enquirer said: “We’re still waiting for sign-off on a scheme submitted 40 weeks ago, compared to the 12 weeks turnaround for applications quoted by the regulator.

“Frankly it’s a struggle to communicate with the regulator or the outsourced registered building control approver.

“We’re completely in the dark about what is happening.”

Another developer warned: “There is widespread confusion about what level of design is required for Gateway 2 applications. Some say RIBA 4 design, then we are told it must be full construction issue works detail.

“There is clearly no understanding of how the industry works. Industry procurement models would need a fundamental change to fall into line with these requirements. It basically means all specialist contractor detailed designs needs to be fixed at pre-construction.”

Some developers are now said to be looking at the possibility of reducing the height of planned projects to avoid the regulatory process.

Trade body, the Fire Industry Association, supports the thrust of the Building Safety Act, but is also deeply concerned about delays to HRB projects.

It describes processes as ‘overly complex and inefficient” and has called on the BSR immediately to review processes, procedures and guidance,

“This is an urgent issue, it is holding back commencement of construction of HRBs”, warns an FIA statement.

“This situation is counter to the accepted need for new housing stock and will significantly impact parts of the country where residential construction is predominantly HRB (rather than lower rise) such as cities.”

The association echoed calls for further guidance on the extent of design information required to reduce the wasted time and effort incurred by design teams and the BSR in submitting and reviewing designs that are at an inappropriate design stage.

The association also wants to see a stepped process of design submission to give developers confidence to develop full detailed designs for approval.

The Building Safety Regulator was approached for comment.