Refurbishing a Flat in a High-Rise: The BSR Rules

Most people planning a flat refurbishment have a mental model from their last project: appoint a builder, notify building control or an approved inspector, start on site. If the flat sits in a higher-risk building, a residential building at least 18 metres or seven storeys tall, that model is now wrong, and discovering it late is the most expensive way to find out. Since the Building Safety Act regime took effect, building work in these buildings goes through the Building Safety Regulator, and for most notifiable work you need the regulator's approval before anything starts.

Work on an existing higher-risk building needs building control approval from the Building Safety Regulator under regulation 12 of the Higher-Risk Buildings Procedures Regulations 2023. This is not the familiar deposit-plans-and-start arrangement: it is a hard stop. The application is assessed, the regulator decides, and only then can work begin. The same discipline that governs new towers at Gateway 2 governs the alteration of existing ones, because the regime cares about one thing: that nobody changes a tall residential building in ways nobody has checked.

Three categories of work sit outside the approval requirement, and knowing them saves real time:

• Exempt work: a defined list in the regulations of minor repair and replacement work that does not affect the structure or fabric of the building.
• Competent person scheme work: jobs self-certified by registered installers under the schemes in the Building Regulations, the way a boiler replacement or new windows are typically certified.
• Emergency repairs: where there is a serious and immediate risk to people's health and safety, work can start at once. The regulator must be notified as soon as possible after the work begins, and a regularisation application follows once it is done.

The regulator's own guidance is explicit that you should not submit an application for work consisting only of these categories. Everything else, you should assume, needs approval first.

The projects MVV is usually asked about sit squarely inside the regime: removing or altering walls, forming new openings, reconfiguring layouts, moving kitchens and bathrooms, altering services that pass through compartment walls or floors, replacing flat entrance doors, anything that touches the structure or the fire strategy of the building. If your project would have needed a building control application in an ordinary building, in a higher-risk building it needs one to the regulator, with a materially higher standard of documentation.

A flat in a higher-risk building is part of a regulated whole. The building has an accountable person, usually the freeholder or management company, with legal duties to manage its safety risks, and a safety case that describes how those risks are controlled. Works that alter compartmentation, fire doors or shared services touch that safety case. Expect to coordinate: licence to alter from the freeholder, information for the accountable person, and drawings that respect the building's fire strategy rather than fighting it. A design team that understands both sides of that conversation removes months of friction.

Decisions from the regulator take time, and 2025 taught everyone to plan for more of it than the statutory targets suggest. The practical consequences are simple. First, the application is on the critical path: design and documentation must be finished before you apply, not sketched and refined during the build. Second, changes after approval are controlled: significant departures from the approved design need the regulator's agreement, so decisions about finishes, layouts and services are worth making properly the first time. Third, one complete application beats two quick ones, every time.

The refurbishments that move fastest through this regime are the ones where the compliance case and the construction drawings are written by the same people. That is how MVV works: design and build under one roof, with consulting structural engineers and fire safety specialists in the team, producing an application that describes the flat you will actually get. If you are planning work in a high-rise block anywhere in London, talk to us before the programme is set, because in this regime the paperwork is the programme.