Scope: which buildings are HRBs?
Higher Risk Building (HRB) defined under Building Safety Act 2022 s.65 + Higher-Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023: residential building of at least 18m in height OR at least 7 storeys (whichever first) containing at least 2 residential units. Care homes + hospitals of same height also HRBs in occupation. Single dwellings (houses, bungalows) NEVER HRBs regardless of height. Most London single-family renovations + extensions therefore outside HRB scope. Mansion-block flat conversions IN HRBs (Barbican EC2, towers in Canary Wharf E14, Pan Peninsula, Stratford One): full HRB regime applies even for individual flat renovations.
Gateway 2 + Gateway 3 (HRB only)
Gateway 2 (pre-construction approval): submit to Building Safety Regulator (BSR — part of HSE) with detailed design + fire strategy + structural strategy + competence declarations. Decision 12 weeks (extendable). No work can start until approved. Fee scaled by building size — typical HRB Gateway 2 £35,000–£185,000+. Gateway 3 (pre-occupation): completion application + as-built golden thread of information. Decision 8 weeks. Fee £20,000–£85,000. No occupation until approved. Both gateways = hard stop with no equivalent local authority sign-off route. Applies to all building work in an HRB — including individual flat renovations + façade works + plant replacement.
Dutyholder regime (all building work, October 2023+)
Building Regulations 2010 amendment (Part 2A) introduced statutory dutyholders for all building work in England: Client, Principal Designer, Principal Contractor, Designer, Contractor. Each has competence + behaviour duties. Client must appoint competent Principal Designer + Principal Contractor (in writing) before work starts; check competence; ensure cooperation. Golden thread = information about the building kept digitally + handed over at completion. Domestic Client exemption: where Client is a private individual having work on their own home, duties transfer to Principal Contractor (or Principal Designer if no contractor). Builderr provides written dutyholder appointments + golden thread file (drawings, calcs, certificates, manuals) at handover as standard.
