If you’re building apartments in England in 2025, the rules are changing fast. Missing a regulation now could mean long delays and higher costs. Here’s a straightforward guide to the most important compliance issues you need to plan for.
Second Staircases – What’s Changing and When
From 30 September 2026, all new residential buildings over 18 metres must have a second staircase. This change, confirmed in the government’s Approved Document B, has a transitional period, but you need to plan early. If your building is close to the 18-metre mark, double-check your height calculations and design now
Practical Tips:
- Get your fire engineer involved before Stage 3. Stair position and width affect both layouts and net space.
- Consider evacuation lifts and refuge areas to meet safety standards without over-engineering.
- Make sure your funder understands the cut-off date and link loan milestones to building control approvals
The Building Safety Act and Gateways
For higher-risk buildings, the Building Safety Regulator (BSR) now requires projects to pass through three Gateways. Gateway 2 is before construction starts, and Gateway 3 is before occupation. Poor submissions are causing costly delays across the sector.
How to Avoid Delays:
- Appoint a principal designer and contractor who can show they meet Building Safety Act competence requirements.
- Start the “Golden Thread” of building information early and keep it updated.
- Do a mock Gateway 2 submission two months before the real one to catch missing fire-stopping or product data.
- Be realistic with Gateway 3 dates. Missing as-built details is one of the most common failure points
Cladding Still Under the Spotlight
Even though new builds shouldn’t have legacy cladding issues, lenders and buyers remain cautious. Government data released in 2025 shows cladding remediation programmes are ongoing, with full completion not expected until 2029. That means your façade choices will be checked carefully by funders and purchasers
Part O and Overheating
Part O of the building regulations is now live and is a real challenge for small, single-aspect flats. It requires developers to prove they’ve designed to reduce overheating risks. That usually means cross-ventilation, external shading, solar-control glass and careful orientation. According to the Future Homes Hub and reporting in The Guardian, summer overheating is a growing concern, so tackling it at design stage is far cheaper than retrofits later.
Future Homes and Buildings Standards
By 2025, all new homes must be zero-carbon ready under the Future Homes and Buildings Standards. This means no more gas boilers, much higher insulation standards, and tighter design for heating and cooling systems. If you’re still trying to cut costs by designing with gas, you’ll face major marketability issues.
Programme Risks to Watch
Height banding: If your building is between 17.9m and 19.5m, decide on your staircase approach now (Pinsent Masons).
Gateway sequencing: Freeze designs earlier so that fire-stopping, cavity barriers and balcony combustibility are locked in before submission
Façade testing: Treat material changes as Gateway-level variations with full test packs.
Commissioning: Keep a proper logbook so you’re ready for Gateway 3 without last-minute data gaps.
Why Good Compliance Pays
Getting compliance right isn’t just about avoiding fines or delays. It speeds up occupancy, keeps insurance costs down and stabilises cash flow. A clean Gateway 3 approval and a façade design that meets lender expectations can also improve your debt terms and widen your exit options.
The Takeaway
In 2025, success comes from being disciplined about process. Plan for the second staircase rule, stay ahead of Gateway requirements, and treat Part O as a design challenge, not a problem. Developers who build compliance into their design from day one will save time, protect margins and build confidence with funders.