UK Property Development Glossary

Plain-English definitions of the 25 terms property developers, investors and BTL landlords meet most often when underwriting UK deals — Article 4, Class MA, BSA Gateway, CIL, S106, HMO, title splitting, Right to Build and more.

Article 4 Direction: A council-issued planning direction that removes specified Permitted Development rights in a defined area — most commonly used to require full planning permission for HMO conversions or office-to-residential schemes.
Building Safety Act Gateway: The three-stage approval regime under the Building Safety Act 2022 for higher-risk buildings (typically 18m+ or 7 storeys+). Gateway 1 is planning, Gateway 2 is pre-construction, Gateway 3 is completion sign-off by the Building Safety Regulator.
Class MA: The Permitted Development right under Class MA of the Town & Country Planning (General Permitted Development) Order allowing change of use from Class E (commercial) to C3 (dwelling) without a full planning application — subject to prior approval.
CIL (Community Infrastructure Levy): A charge that local authorities can levy on new developments per square metre of net additional floorspace. Rates vary by council and use class — Scapely surfaces local CIL rates as part of its build-cost calculations.
Commercial-to-Residential: Converting a commercial property (typically Class E offices, shops or light industrial) into residential use. Often done via Class MA Permitted Development to bypass full planning, subject to floor-area, daylight and contamination criteria.
EPC (Energy Performance Certificate): A statutory rating of a property's energy efficiency, A (best) to G (worst). Required to market a property and increasingly material for buy-to-let — minimum E for new tenancies, with proposals to raise to C.
Freehold vs Leasehold: Freehold means outright ownership of the land and building indefinitely. Leasehold means time-limited ownership of a unit (typically a flat) under a lease from the freeholder, with ground rent and service charges payable.
HMO (House in Multiple Occupation): A property rented by three or more unrelated tenants forming two or more households who share kitchen or bathroom facilities. Large HMOs (5+ tenants) are mandatorily licensed; smaller HMOs may need additional or selective licensing.
Land Assembly: Combining adjacent plots — often under different owners — into a single developable site. Typically requires options agreements, conditional contracts or a strategic acquisition campaign.
Listed Building: A building protected under the Planning (Listed Buildings and Conservation Areas) Act 1990 because of its architectural or historic significance. Grade I, II*, II — alterations require Listed Building Consent.
Permitted Development (PD): Specific categories of development that can proceed without a full planning application under the General Permitted Development Order. Includes minor extensions, certain change-of-use cases and householder works.
Prior Approval: A lighter-touch planning consent process for some PD rights (e.g. Class MA, larger householder extensions). The council can only refuse on specified grounds — not on principle.
PTAL (Public Transport Accessibility Level): A 0–6b score used in London to measure how well a site is served by public transport. Critical for planning policy compliance, density and parking standards.
S106 (Section 106 Agreement): A planning obligation under Section 106 of the Town & Country Planning Act 1990, used to secure affordable housing, public-realm contributions or transport improvements as a condition of planning consent.
Title Splitting: Dividing a single property title into multiple Land Registry titles — typically when converting a house into flats or a HMO. Requires separate leases, freehold management structure and Land Registry approval.
Title Register: The official HM Land Registry record of a property's ownership, tenure type, charges, restrictions and (where relevant) lease terms. Each register costs £3 from HM Land Registry and is the only authoritative source of tenure information.
BTR (Build-to-Rent): Purpose-built rental developments owned and managed long-term by a single institutional landlord, with shared amenities and on-site management — distinct from buy-to-let or PRS.
PBSA (Purpose-Built Student Accommodation): Student housing developed and operated specifically for the student market. Often falls under sui generis use class with bespoke planning policy in university cities.
Use Class: The Town & Country Planning (Use Classes) Order classification system: C3 (dwelling), C4 (small HMO), Class E (commercial, business, services), F1/F2 (community), Sui Generis (one-off uses like HMO 7+).
Conservation Area: Areas designated by councils for special architectural or historic interest. PD rights are restricted (Article 4 commonly applied), demolition needs consent, and tree works are controlled.
Green Belt: Statutory open land around major UK cities where development is restricted to protect against urban sprawl. The 2024 NPPF reforms introduced a 'grey belt' concept to allow limited release of lower-quality green-belt land.
Air Rights / Airspace Development: Building additional floors above existing buildings — typically permitted under Class AA (homes) or Class AC/AD PD rights subject to height, daylight and structural-feasibility checks.
Brownfield: Previously developed land — typically former industrial, commercial or institutional sites. National policy strongly supports brownfield-first development to ease pressure on greenfield/Green Belt.
Density (dph): Dwellings per hectare — the principal density metric for residential schemes. London Plan and most local plans set density ranges by PTAL and town-centre tier.
Right to Build: Self-Build and Custom Housebuilding Act 2015 obligation requiring councils to maintain a register of demand and to grant sufficient planning permissions to meet that demand.