Planning Permission & Building Regulations
Navigating planning can feel overwhelming. At APEX, we handle every aspect — from initial feasibility to final sign-off — so you don't have to.
Permitted Development Rights
Many home extensions in London can be built under Permitted Development (PD) rights, meaning no formal planning application is required. This typically applies to:
- Single-storey rear extensions (up to 3m for semi/terraced, 4m for detached, or 6m/8m under Prior Approval)
- Side extensions (up to half the width of the original house)
- Loft conversions adding up to 40m³ (terraced) or 50m³ (detached/semi)
- Extensions that do not exceed the height of the existing roof
Important: PD rights can be restricted in Conservation Areas, Areas of Outstanding Natural Beauty, and on Listed Buildings. We always verify your property's PD status before proceeding.
Full Planning Permission
If your project exceeds PD limits, we manage the full Householder Planning Application on your behalf. This includes:
- Pre-application consultation with the Local Planning Authority (LPA)
- Preparation of architectural drawings and design statements
- Heritage, daylight, and neighbour impact assessments
- Full application submission and liaison with the planning officer
- Management of any conditions attached to approval
Typical turnaround for a standard Householder application is 8 weeks from submission. We advise starting this process early to avoid delays to your build timeline.
Building Regulations
Separate from planning permission, all extensions and loft conversions must comply with Building Regulations. These cover:
- Structural integrity (Part A) — steel calculations and foundations
- Fire safety (Part B) — escape routes, fire doors, and smoke alarms
- Thermal efficiency (Part L) — insulation standards for new walls, roofs, and glazing
- Drainage and waste (Part H)
- Electrical safety (Part P) — all new circuits must be certified
APEX manages the Building Control process end-to-end, including inspections at every stage, and delivers your Completion Certificate upon handover — essential for resale and insurance.
Party Wall Agreements
If your extension or loft conversion involves work within 3 metres of a neighbouring property's boundary, or directly on a shared wall, you are legally required to serve a Party Wall Notice under the Party Wall etc. Act 1996.
We coordinate Party Wall Surveyors, manage the notice period, and ensure all agreements are in place before construction begins — preventing disputes and protecting your project timeline.