Building safety’s cliff-edge week: and what comes after

Last week the property industry reached a moment long seen coming. On Wednesday, the second-staircase requirement for new residential buildings above 18 metres took effect. On Thursday, the Building Safety Levy began. Two changes, 48 hours apart, will shape what gets built, where and at what cost for the rest of the decade.

This is not simply more regulation for a sector already struggling with viability. The Building Safety Act was always going to change how we design, fund and deliver buildings; 2026 has removed most of the uncertainty about how.

Known since 2023, the second-staircase rule was priced in long ago: fire authorities, funders and insurers had little appetite for single-stair tall schemes. The lasting effect is on form. Around 18 metres, a second core heavily erodes floorplate efficiency, so schemes now stop just below the threshold or go much higher to pay for the extra stair. That has real consequences for density in the urban locations where homes are most needed.

The levy reaches further, because it is not confined to higher-risk buildings. Any scheme of ten or more homes, or 30 or more student bedspaces, submitted into building control from 1 October will pay a charge on its residential floorspace. Rates range from under £13 per square metre in County Durham to more than £100 in Kensington and Chelsea, with a 50% brownfield discount.

Most of us support the principle that leaseholders should not pay for historic defects. But the levy is a development cost that belongs alongside Section 106 and CIL in the appraisal, not an afterthought. On a mid-sized London scheme it can reach several hundred thousand pounds. Liability attaches to the planning permission and an unpaid levy can hold up a completion certificate, so it cannot be managed away at the end. Nor is a rushed submission the answer: an application rejected and resubmitted after Thursday will attract the levy anyway.

The Building Safety Regulator has made real progress since becoming a standalone body in January. A year ago, median approval times for new higher-risk buildings were 43 weeks and fewer than four in ten applications succeeded; now the figures are 22 weeks and 92%. Twenty-two weeks is still well over the 12-week statutory target, and the pre-deadline surge will test the regulator again. My advice to clients: programme Gateway 2 as a five-to-six month hold, not three, and brief lenders and investors accordingly.

The biggest cause of delay, the regulator says, is now poor-quality submissions. The regime rewards design that is complete, coordinated and properly evidenced, and penalises the old habit of resolving detail on site.

Building safety can no longer be a compliance check at the end of design. It must be embedded from feasibility onwards: in height and form, procurement, the appointment of competent dutyholders and the golden thread of information. Investors need due diligence covering the building safety case, the golden thread and remediation liabilities that now extend back 30 years. Owners of build to rent, student and later living portfolios are inheriting accountable person duties that need proper resourcing.

Proportionality is also improving, from removing telecoms work from Gateway 2 to an independent review of the higher-risk regime. Grenfell exposed a system in which safety was too often traded against cost and programme; this week’s changes are part of the settlement designed to end that. Businesses that thrive will stop treating building safety as a hurdle and start treating it as the way projects are conceived, funded and run. The rules are finally settled. The task now is to deliver safe homes within them, at the pace the country needs.