Extension Planning Tips for London Victorian Terraces: Maximising Permitted Development

UNDER THE TOWN AND COUNTRY PLANNING (GENERAL PERMITTED DEVELOPMENT) ORDER 2015 (GPDO), CLASS A COVERS REAR EXTENSIONS TO HOUSES IN ENGLAND:

SINGLE-STOREY REAR EXTENSION LIMITS: - DETACHED HOUSE: UP TO 8.0M PROJECTION FROM THE ORIGINAL REAR WALL OF THE HOUSE AS BUILT - SEMI-DETACHED OR TERRACED HOUSE (ALL LONDON VICTORIAN TERRACES): UP TO 6.0M PROJECTION FROM THE ORIGINAL REAR WALL

CRITICAL DEFINITIONS: "ORIGINAL REAR WALL" = THE REAR WALL OF THE ORIGINAL HOUSE AS BUILT OR AS IT STOOD ON 1 JULY 1948. IF A PREVIOUS EXTENSION EXISTS, ITS OUTER WALL IS NOT THE "ORIGINAL REAR WALL" — THE PROJECTION ALLOWANCE IS MEASURED FROM THE ORIGINAL HOUSE REAR WALL, NOT FROM AN EXISTING EXTENSION.

HEIGHT LIMITS FOR SINGLE-STOREY REAR EXTENSIONS: - MAXIMUM 4.0M RIDGE HEIGHT - MAXIMUM EAVE HEIGHT: MUST NOT EXCEED THE EXISTING HOUSE EAVE HEIGHT AT THE EXTENSION SIDE - WITHIN 2M OF A BOUNDARY: MAXIMUM 3.0M EAVE HEIGHT

TIPS TO MAXIMISE PERMITTED DEVELOPMENT: 1. MEASURE FROM THE CORRECT ORIGINAL REAR WALL. IF A PREVIOUS BACK ADDITION (VICTORIAN OUTRIGGER) EXISTS, THE PERMITTED DEVELOPMENT ALLOWANCE IS MEASURED FROM THE OUTER FACE OF THE ORIGINAL REAR WALL OF THE MAIN HOUSE — NOT FROM THE BACK OF THE OUTRIGGER. THIS CAN MEAN THAT APPARENT PD SPACE IS ALREADY USED BY THE OUTRIGGER. 2. SINGLE-STOREY = 4.0M RIDGE MAXIMUM. DO NOT EXCEED 4.0M — EVEN A FLAT ROOF TO 4.1M REQUIRES PLANNING PERMISSION. 3. THE PRIOR APPROVAL PROCESS (NEIGHBOUR CONSULTATION SCHEME, CLASS A.1) ALLOWS TERRACED HOUSES TO EXTEND UP TO 6.0M WITHOUT A FULL PLANNING APPLICATION — BUT REQUIRES NOTIFICATION OF NEIGHBOURS AND APPROVAL BY THE LOCAL PLANNING AUTHORITY. THE EXTENSION MUST STILL MEET ALL OTHER PD LIMITS (HEIGHT, MATERIALS, DESIGN). 4. MATERIALS MUST BE SIMILAR IN APPEARANCE TO THE EXISTING HOUSE — NOT IDENTICAL, BUT SIMILAR. THIS IS A PD CONDITION THAT PLANNING OFFICERS OCCASIONALLY ENFORCE IF A STARK CONTRAST IS PROPOSED (E.G. STEEL/TIMBER CLADDING ON A BRICK HOUSE MAY BE REFUSED AS DISSIMILAR). 5. USE A LAWFUL DEVELOPMENT CERTIFICATE (LDC) TO CONFIRM PD STATUS — A LDC PROVIDES LEGAL CERTAINTY THAT THE PROPOSED WORKS ARE PERMITTED DEVELOPMENT, PROTECTING THE HOMEOWNER AND FACILITATING FUTURE SALE.

THE PRIOR APPROVAL PROCESS UNDER GPDO 2015, PART 1, CLASS A.1 ALLOWS EXTENSIONS LARGER THAN THE STANDARD PD LIMITS (4M FOR DETACHED, 3M FOR TERRACED — THE ORIGINAL LOWER LIMITS) BUT STILL BELOW THE ENLARGED LIMITS (8M/6M) TO BE BUILT WITHOUT A FULL PLANNING APPLICATION — SUBJECT TO NEIGHBOUR CONSULTATION:

HOW PRIOR APPROVAL WORKS: 1. APPLICANT NOTIFIES THE LOCAL PLANNING AUTHORITY (LPA) OF THE PROPOSED DEVELOPMENT USING THE STANDARD PRIOR APPROVAL FORM (AVAILABLE ON THE PLANNING PORTAL OR BOROUGH WEBSITE). FEE: £120 (STANDARD PRIOR APPROVAL FOR LARGER REAR EXTENSIONS AS OF 2024). 2. THE LPA NOTIFIES ADJACENT OWNERS (IMMEDIATELY ADJOINING NEIGHBOURS) OF THE PROPOSED EXTENSION. 3. NEIGHBOURS HAVE 21 DAYS TO MAKE REPRESENTATIONS. 4. THE LPA THEN CONSIDERS ANY OBJECTIONS AND DETERMINES WHETHER THE IMPACT ON NEIGHBOURS\ AMENITY IS ACCEPTABLE. THE LPA CAN ONLY CONSIDER: IMPACT ON NEIGHBOURING PROPERTIES\ AMENITY (DAYLIGHT, OUTLOOK, PRIVACY) — NOT DESIGN, MATERIALS, OR BROADER PLANNING POLICY. 5. THE LPA MUST DETERMINE THE APPLICATION WITHIN 42 DAYS. IF NO DETERMINATION IS MADE WITHIN 42 DAYS, PRIOR APPROVAL IS DEEMED GRANTED.

KEY POINTS FOR LONDON TERRACED HOUSES: - THE 6.0M LIMIT FOR TERRACES IS ONLY AVAILABLE THROUGH PRIOR APPROVAL (ABOVE 3M PD) — BUT IN LONDON\'S DENSE TERRACE STREETS, NEIGHBOUR OBJECTIONS ON DAYLIGHT AND OUTLOOK ARE VERY COMMON FOR EXTENSIONS OVER 4.0-5.0M PROJECTION. - PRIOR APPROVAL DOES NOT REMOVE OTHER PD CONDITIONS (HEIGHT LIMITS, MATERIALS SIMILARITY, COVERAGE LIMITS). - A PRIOR APPROVAL IS NOT A PLANNING PERMISSION — BUILDING REGULATIONS ARE STILL REQUIRED SEPARATELY.

WHEN TO CHOOSE FULL PLANNING APPLICATION INSTEAD: - WHERE THE EXTENSION EXCEEDS 6.0M (TERRACED) - WHERE THE EXTENSION IS DOUBLE-STOREY - WHERE CONSERVATION AREA OR ARTICLE 4 RESTRICTIONS APPLY - WHERE THE DESIGN INCLUDES GLAZED ROOFS, FRAMELESS GLASS WALLS, OR MATERIALS VERY DIFFERENT FROM THE EXISTING HOUSE (WHERE DESIGN MATTERS TO THE OUTCOME)

LONDON HAS APPROXIMATELY 1,000 CONSERVATION AREAS — COVERING MANY OF ITS VICTORIAN TERRACE STREETSCAPES. IN A CONSERVATION AREA, THE FOLLOWING RESTRICTIONS APPLY TO EXTENSIONS:

WHAT IS RESTRICTED IN CONSERVATION AREAS: - SIDE EXTENSIONS VISIBLE FROM THE STREET: REQUIRE PLANNING PERMISSION (GPDO REMOVES PD RIGHTS FOR SIDE EXTENSIONS IN CONSERVATION AREAS) - REAR EXTENSIONS: PD RIGHTS FOR REAR EXTENSIONS ARE GENERALLY RETAINED IN CONSERVATION AREAS — BUT MAY BE REMOVED BY ARTICLE 4 DIRECTIONS - ROOF EXTENSIONS (DORMERS ON REAR SLOPES): PD RIGHTS ARE REMOVED IN CONSERVATION AREAS — PLANNING PERMISSION REQUIRED - CLADDING (RENDERING, STONE CLADDING, ETC.): REQUIRES PLANNING PERMISSION IN CONSERVATION AREAS

ARTICLE 4 DIRECTIONS: AN ARTICLE 4 DIRECTION IS AN ORDER MADE BY THE BOROUGH THAT REMOVES SPECIFIC PERMITTED DEVELOPMENT RIGHTS IN A DEFINED AREA. IN MANY LONDON CONSERVATION AREAS, ARTICLE 4 DIRECTIONS REMOVE: - PD RIGHTS FOR REAR EXTENSIONS - PD RIGHTS FOR FRONT GARDEN HARDSTANDING - PD RIGHTS FOR CHANGES TO WINDOWS AND DOORS ON PRINCIPAL ELEVATIONS - PD RIGHTS FOR SATELLITE DISHES

CHECKING FOR ARTICLE 4 DIRECTIONS: ALWAYS CHECK THE BOROUGH\'S LOCAL PLAN AND CONSERVATION AREA APPRAISAL BEFORE ASSUMING PD RIGHTS APPLY IN A CONSERVATION AREA. THE BOROUGH\'S WEBSITE USUALLY LISTS ARTICLE 4 DIRECTIONS BY AREA. ALTERNATIVELY, REQUEST PRE-APPLICATION ADVICE (£200-600 BOROUGH FEE) — THE OFFICER WILL CONFIRM WHAT PERMISSION IS REQUIRED.

TIPS FOR CONSERVATION AREA EXTENSIONS: 1. USE TRADITIONAL MATERIALS THAT MATCH THE HOST BUILDING — LONDON STOCK BRICK, LEAD OR ZINC FLAT ROOFING, TIMBER WINDOWS. CONTEMPORARY MATERIALS ON A VISIBLE EXTENSION WILL USUALLY BE REFUSED. 2. KEEP THE EXTENSION SUBORDINATE TO THE HOST BUILDING — CONSERVATION OFFICERS DISLIKE EXTENSIONS THAT DOMINATE THE ORIGINAL HOUSE. 3. PRE-APPLICATION ADVICE IS ESPECIALLY VALUABLE IN CONSERVATION AREAS — IT SAVES WASTED DESIGN COSTS ON AN UNACCEPTABLE SCHEME. 4. A DESIGN AND ACCESS STATEMENT EXPLAINING HOW THE EXTENSION RESPECTS THE CHARACTER AND APPEARANCE OF THE CONSERVATION AREA IS ESSENTIAL FOR PLANNING APPLICATIONS IN CONSERVATION AREAS.

THE FOLLOWING ARE THE MOST COMMON PLANNING MISTAKES MADE BY LONDON VICTORIAN TERRACE HOMEOWNERS PLANNING EXTENSIONS:

MISTAKE 1: MEASURING PROJECTION FROM THE WRONG WALL. THE MOST COMMON PD MEASUREMENT ERROR IS MEASURING FROM THE BACK OF AN EXISTING BACK ADDITION OR EXTENSION RATHER THAN THE ORIGINAL REAR WALL OF THE MAIN HOUSE. THIS LEADS TO EXTENSIONS THAT EXCEED PD LIMITS WITHOUT THE HOMEOWNER REALISING. FIX: OBTAIN ORIGINAL PLANNING DRAWINGS OR 1948 OS MAPS TO CONFIRM THE ORIGINAL REAR WALL POSITION.

MISTAKE 2: NOT OBTAINING AN LDC (LAWFUL DEVELOPMENT CERTIFICATE). BUILDING AN EXTENSION WITHOUT AN LDC MEANS THE PD STATUS IS UNCONFIRMED. ON SALE, SOLICITORS WILL OFTEN REQUIRE EVIDENCE — AN LDC OR COPY OF THE PLANNING PORTAL PRIOR APPROVAL DECISION. FIX: ALWAYS APPLY FOR AN LDC OR PRIOR APPROVAL BEFORE BUILDING — EVEN IF CONFIDENT THE WORKS ARE PD.

MISTAKE 3: STARTING BEFORE PRIOR APPROVAL IS GRANTED. STARTING A PRIOR APPROVAL EXTENSION BEFORE THE 42-DAY DETERMINATION PERIOD EXPIRES (OR BEFORE WRITTEN PRIOR APPROVAL IS RECEIVED) IS A PLANNING BREACH. FIX: WAIT FOR WRITTEN CONFIRMATION FROM THE LPA THAT PRIOR APPROVAL HAS BEEN GRANTED (OR THAT IT IS NOT REQUIRED).

MISTAKE 4: IGNORING CONSERVATION AREA STATUS. ASSUMING PD RIGHTS APPLY IN A CONSERVATION AREA WITHOUT CHECKING FOR ARTICLE 4 DIRECTIONS. THIS IS THE MOST EXPENSIVE MISTAKE — POTENTIALLY REQUIRING ENFORCEMENT ACTION, PLANNING RETROSPECTIVE APPLICATION, OR EVEN DEMOLITION. FIX: CHECK THE BOROUGH\'S WEBSITE FOR ARTICLE 4 DIRECTIONS BEFORE ANY WORK. OBTAIN PRE-APPLICATION ADVICE.

MISTAKE 5: NOT CHECKING FOR PROTECTED TREES. TPO (TREE PRESERVATION ORDER) TREES IN THE GARDEN OR CONSERVATION AREA TREES (ALL TREES ABOVE 75MM DIAMETER IN A CONSERVATION AREA ARE PROTECTED) REQUIRE CONSENT BEFORE ANY WORK — INCLUDING WORK NEEDED TO FACILITATE AN EXTENSION. FIX: IDENTIFY ALL TREES ON SITE AND THEIR STATUS. APPLY FOR TREE WORK CONSENT (SECTION 211 NOTICE FOR CA TREES — FREE, 6-WEEK WAIT; OR TPO APPLICATION TO THE BOROUGH) BEFORE STARTING.

COSTS (PLANNING APPLICATIONS, LONDON 2024-2026): LDC (LAWFUL DEVELOPMENT CERTIFICATE): £258 (ENGLAND, 2024 FEE) PRIOR APPROVAL (LARGER REAR EXTENSION): £120 HOUSEHOLDER PLANNING APPLICATION: £528 PRE-APPLICATION ADVICE (BOROUGH FEE): £200-600 PLANNING CONSULTANT/ARCHITECT FEES: £1,500-5,000 (DEPENDING ON COMPLEXITY)