A key compliance deadline for the new requirement to include a second staircase in taller residential buildings has now taken effect, closing off most transitional routes for schemes that were hoping to proceed under older rules. Project teams across England are reviewing live designs, planning statuses and procurement plans to judge whether consented cores can still stand or need to be reworked. Industry briefings suggest building control bodies and clients are preparing for an uptick in redesign submissions as schemes over the height threshold firm up their compliance pathways. Contractors report growing pressure to lock down core layouts early to avoid programme slippage later in the gateway process. Funders and insurers are also understood to be asking for clearer evidence that evacuation strategies and access for firefighting are embedded from RIBA Stage 2 onward. The direction of travel is unambiguous: for new high‑rise homes, a second staircase is rapidly becoming a baseline expectation rather than an exception.
TL;DR
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– Most new high‑rise residential schemes now need a second staircase, with limited transitional wriggle room left.
– Design teams should revisit core layouts, evacuation strategies and services coordination before tender.
– Expect planning amendments, revised building control submissions and procurement re‑sequencing on affected plots.
– Cost and net‑to‑gross shifts are likely, so developers may reappraise mix, amenities and phasing to keep viability in play.
Where projects stand as the cut-off bites
/> The close of transitional arrangements is prompting a last round of sanity checks: is the scheme within the height scope, is the design locked, and can existing consents support a compliant core without wholesale replanning? Many clients are weighing the speed of submitting amendments against the risk of pushing on and facing later redesign, with particular focus on lift sizes, refuge spaces, smoke control and the knock‑on effect of a larger core on net saleable area.
For contractors, the immediate pinch points are coordination and procurement. A second stair affects more than egress; it touches risers, ventilation, MEP routes, facade interfaces and the sequencing of offsite elements. Tenderers are increasingly qualifying programme allowances for potential redesign iterations, while specialist stair, lift and smoke control suppliers are fielding early engagement requests to de‑risk detailing.
# What it means for project teams
/> Architects and fire engineers will need to evidence that the second staircase integrates with a coherent evacuation and firefighting strategy rather than being a bolt‑on. Quantity surveyors are already revisiting cost plans to account for core growth, potential loss of units and re‑proportioning of amenity spaces. Planning consultants may advise on minor‑material amendments where layouts shift, while legal advisers check any s106 interactions if housing mix or tenure distribution changes.
Design for manufacture and assembly (DFMA) is under a microscope: volumetric and panelised systems may require revised module sizes or different corridor arrangements to accommodate two stairs without compromising tolerance or logistics. On site, temporary works, crane positions and delivery routes can also change where cores move or enlarge.
# A plausible site scenario
/> A city‑centre plot with a consented tower is moving into Stage 3 when the deadline lands. The developer pauses to test a twin‑stair core, finding that two mid‑rise plant rooms must be re‑stacked and one refuse chute relocated. The architect proposes flipping certain one‑bed units to maintain daylighting and avoid deep plans, while the QS flags a marginal drop in net‑to‑gross that needs offsetting through a revised mix. The contractor updates the prelims to cover additional vertical logistics and a re‑sequenced MEP install. A short planning amendment is lodged to regularise elevations where additional louvres and smoke shafts pierce the facade.
Risks, timings and the road ahead
/> The market is now assessing how quickly authorities and regulators can process a wave of amended plans and fire statements. Local authority capacity, coordination with building control approvers, and the readiness of supply chains to meet different stair configurations will shape lead‑in times. Lenders and insurers are expected to continue leaning towards schemes that can demonstrate compliance clearly, rewarding projects that front‑load design certainty and penalising those that defer decisions into construction.
# What to watch next
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– Clarifications on the precise scope and edge cases, including mixed‑use and build‑to‑rent configurations.
– How local planning authorities handle minor‑material amendments where core changes affect elevations.
– Market response on viability, particularly whether mix changes or phasing strategies become the norm.
– Supply chain capacity for compliant stair, lift and smoke control packages as demand shifts.
# Caveats
/> There is variation in how individual authorities and building control bodies interpret transitional positions, so outcomes can differ by scheme and location. Some projects may remain legitimately outside scope based on timing, use class or height, provided evidence is clear. The long‑term performance of two‑stair solutions will depend on coordinated fire strategies and not solely on geometry, and cost movements will vary widely by typology and site constraints.
The second staircase requirement is bedding in, and market practice is converging on earlier, clearer fire and core decisions to keep programmes on track. The live question is whether design ingenuity and planning pragmatism can preserve viability while delivering the safety outcomes policymakers are seeking.
FAQ
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What is meant by a “second staircase” in this context?
It refers to providing two independent stair cores for vertical escape and firefighting access in taller residential buildings. The intent is to strengthen evacuation options and resilience, complementing other fire safety measures.
# Does the requirement apply to all new buildings?
/> The focus is on new high‑rise residential schemes above a defined height threshold, with specific scope and exceptions set out in policy and guidance. Mixed‑use buildings and conversions can require case‑by‑case interpretation depending on height, use and design.
# What happens to schemes already in planning?
/> Many projects relied on transitional arrangements, but the window for most new starts has now effectively closed. Teams should confirm their position with planning and building control, and prepare for amendments if a compliant second stair is now necessary.
# Will this add cost or reduce unit numbers?
/> A larger or reconfigured core can affect net‑to‑gross and may require re‑planning of unit layouts, which can carry cost implications. Some developers are exploring mix adjustments, amenities rebalancing or phasing to maintain viability.
# How should contractors respond right now?
/> Contractors are prioritising early design coordination around cores, lifts, smoke control and services to avoid late changes. Engaging key specialists sooner and re‑sequencing procurement to lock in compliant details are common risk‑reduction steps.
