The Building Safety Act 2022 rewrote the rules of residential construction in England, and building services sit closer to the centre of that change than many design teams yet appreciate. On higher-risk buildings, MEP design can no longer mature quietly through the construction phase: it must be substantially complete, coordinated and evidenced before work starts on site, then maintained as a digital golden thread for the life of the building. Fire dampers, riser penetrations, smoke control, sprinklers and evacuation alert systems have become matters of statutory record. Here is what the regime actually requires, and what it means for how MEP design should be procured and programmed.
What counts as a higher-risk building?
A higher-risk building is one at least 18 metres in height or with at least seven storeys, containing at least two residential units. That is the test set out in the government’s criteria guidance. During design and construction the net is slightly wider: the Building Safety Regulator (BSR) acts as building control authority for buildings that meet the height or storey threshold and contain two residential units, or are a hospital or care home. Mixed-use schemes are caught as well: a tall commercial building with two flats within it qualifies.
The regulator itself has recently changed shape. Incubated within the Health and Safety Executive, the BSR became a standalone non-departmental public body sponsored by the Ministry of Housing, Communities and Local Government on 27 January 2026, as recorded in its strategic plan for 2026 to 2027.
For MEP designers, classification is a day-one question. Whether a scheme is a higher-risk building determines who approves the design, how long approval takes, what information must be produced, and how changes are handled from Stage 4 onwards. Discovering the answer at tender stage is far too late.
How do the gateways change your design programme?
In one sentence: they move the moment of truth from practical completion to before construction begins. The regime runs three gateways. Gateway one sits at planning, ensuring fire safety is considered in the application. Gateway two is the decisive one for design teams: building control approval from the BSR must be secured before building work starts, and carrying out work without it is a criminal offence. Gateway three requires a completion certificate confirming the finished work meets building regulations before a higher-risk residential building can be registered for occupation.
The BSR assesses gateway two applications within 12 weeks for a new higher-risk building and 8 weeks for work to an existing one, with extensions agreed on complex projects. Real-world determinations have often taken longer, and the regulator has committed to responding to non-complex new-building applications in 18 weeks or less by the end of March 2027.
The consequence for MEP design is blunt: Stage 4 has to mean Stage 4. A gateway two application must demonstrate how the proposals comply with building regulations. For building services that means resolved riser strategies, penetrations through compartment lines with their fire-stopping details, damper schedules, smoke ventilation performance, sprinkler and evacuation alert provision, and a coordinated model that will survive scrutiny. The traditional habit of leaving services “design development” to the contractor is no longer a programme convenience; it is a change-control liability.
What does the golden thread mean for MEP information?
The golden thread is a digital record of the information needed to show a building complies with building regulations and to manage its safety through its life. Government guidance requires it to be kept digitally, secure from unauthorised access and version-controlled. During design and construction the client must maintain, among other things, drawings and plans, a building regulations compliance statement, a construction control plan and a fire and emergency file. Before applying for a completion certificate, the client must show that the information has been handed to the building’s accountable person in a format they can actually use.
For building services this is a bigger cultural shift than for any other discipline, because MEP generates the densest, most change-prone information on a project. As-installed drawings, commissioning results, damper and fire-stopping records, cause-and-effect matrices and plant data must exist as structured, retrievable digital information, not a box of unsearchable PDFs at handover. Teams already working in Revit with disciplined naming, revision control and coordinated models are most of the way there; teams that are not will feel the regime as friction on every submission.
Change control ends the late services switch
MEP is the discipline where late change concentrates: plant substitutions, riser re-routes, value-engineered equipment swaps. On a higher-risk building those habits now carry statutory weight. The government’s design and construction guidance collection sets formal procedures for making changes to a higher-risk building project, and dutyholders must operate a mandatory occurrence reporting system for structural and fire safety concerns. Significant changes need approval before they are built. A substitution that unravels the fire strategy, or a re-route that adds unplanned penetrations through a compartment wall, is no longer absorbed quietly on site. It is documented, justified and, where major, approved. The late swap has stopped being cheap.
The same regime places legal duties on clients, principal designers and principal contractors, including competence requirements that form part of the gateway two application itself. Appointing consultants who can evidence relevant higher-risk building experience is now part of demonstrating your own compliance.
Designing for the regime, not around it
The practical response is to front-load: settle the fire strategy and services interfaces early, complete coordination before the gateway two submission rather than after it, and build the evidence trail as the design progresses instead of reconstructing it at handover. At Orion Park in West Ealing (95 all-electric apartments including a Higher-Risk Building under the Act), AMF’s MEP design has been shaped by exactly these disciplines: gateway-ready Stage 4 information, coordinated in BIM, with fire-critical services documented for the golden thread rather than for the drawing issue sheet. It is the same completeness standard we apply across our residential work, from Cyprus Beckton’s 211-apartment ambient-loop scheme to High Path Estate’s gas-free regeneration in South Wimbledon.
The Building Safety Act rewards teams that get MEP right first time. It penalises, in programme and cost, those who treat services as a detail to resolve later. If you are bringing forward a scheme that will fall under the regime, involve your MEP designer before the classification, gateway strategy and information plan are fixed. AMF provides MEP design from RIBA Stage 3 through to handover, with executive oversight and a named project coordinator on every project. Talk to us early, and the gateways become milestones rather than roadblocks.