Brick Slips and External Cladding for London Home Extensions and Renovations

BRICK SLIPS (THIN-FORMAT BRICK FACINGS — TYPICALLY 20 TO 25MM THICK SLICES OF REAL FIRED CLAY BRICK) ARE USED TO GIVE A NEW EXTENSION OR CONCRETE BLOCK SUBSTRATE THE APPEARANCE OF TRADITIONAL BRICKWORK WITHOUT THE STRUCTURAL THICKNESS OF A FULL FACING BRICK WALL. THEY ARE PARTICULARLY POPULAR IN LONDON BECAUSE THEY ALLOW A NEW EXTENSION TO VISUALLY MATCH THE EXISTING VICTORIAN LONDON STOCK BRICKWORK OF THE ORIGINAL TERRACE.

LEADING BRICK SLIP SUPPLIERS FOR LONDON VICTORIAN TERRACE MATCHING: IBSTOCK BRICK (THE DOMINANT UK BRICK SLIP MANUFACTURER) PRODUCES BRICK SLIPS IN ALL MAJOR LONDON BRICK TYPES INCLUDING: IBSTOCK LONDON STOCK YELLOW (THE CLASSIC LONDON VICTORIAN TERRACE BRICK — YELLOW-GREY BODY, CHARACTERISTIC IRREGULAR SURFACE) — AVAILABLE AS A SLIP. IBSTOCK RECLAIMED LONDON STOCK EFFECT (BRICK SLIPS WITH A RECLAIMED APPEARANCE — TUMBLED, VARIED COLOUR) — THE MOST POPULAR CHOICE FOR MATCHING PERIOD LONDON TERRACE BRICKWORK ON NEW EXTENSIONS. KETLEY BLUE BRINDLE BRICK SLIP (FOR MATCHING DARKER VICTORIAN BLUE ENGINEERING BRICK PLINTHS ON LONDON TERRACE EXTENSIONS).

BRICK SLIP SYSTEMS: TWO MAIN INSTALLATION APPROACHES ARE USED IN LONDON: ADHESIVE-FIXED BRICK SLIPS ON CEMENT BOARD OR CONCRETE BLOCK SUBSTRATE: SIKA BRICK SLIP ADHESIVE OR MAPEI MAPEBAND PE — THE SLIP IS INDIVIDUALLY BONDED AND POINTED WITH LIME-COMPATIBLE JOINT MORTAR (NHL 2.5 OR 3.5 — NOT OPC CEMENT, WHICH STAINS AND IS TOO STRONG FOR THE SLIP BOND). MECHANICALLY FIXED BRICK SLIP PANELS (SPEEDYPANELS, WIENERBERGER BRICK SLIP RAIL SYSTEMS): PRE-ASSEMBLED PANELS OF BRICK SLIPS ON A BACKING CARRIER — FIXED TO THE WALL WITH MECHANICAL FIXINGS, WITH JOINTS POINTED AFTER PANEL INSTALLATION. FASTER TO INSTALL THAN INDIVIDUAL SLIP FIXING BUT MORE EXPENSIVE IN MATERIAL COST.

PLANNING CONSIDERATION: IN LONDON CONSERVATION AREAS AND ON ARTICLE 4 PROPERTIES, THE EXTERNAL MATERIAL OF AN EXTENSION MUST MATCH OR COMPLEMENT THE CHARACTER OF THE ORIGINAL BUILDING. BRICK SLIPS THAT ACCURATELY MATCH THE ORIGINAL VICTORIAN YELLOW STOCK BRICK OF THE HOST TERRACE ARE LIKELY TO BE ACCEPTABLE IN CONSERVATION AREAS WHERE FULL BRICK (IN MATCHING SPECIFICATION) WOULD ALSO BE ACCEPTABLE — BUT CONFIRMATION FROM THE LOCAL PLANNING AUTHORITY IS ADVISABLE BEFORE PROCEEDING.

SILICONE RENDER IS THE DOMINANT EXTERNAL FINISH FOR CONTEMPORARY LONDON REAR EXTENSIONS — IT PROVIDES A CLEAN, MODERN CONTRAST TO THE ORIGINAL VICTORIAN BRICKWORK OF THE TERRACE, AND IS EASIER AND CHEAPER TO APPLY THAN BRICK OR BRICK SLIPS.

K-REND SILICONE TC15 (THE MOST WIDELY SPECIFIED SILICONE RENDER ON LONDON EXTENSIONS): K-REND SILICONE TC15 IS A THROUGH-COLOURED SILICONE RENDER APPLIED IN A 1.5MM SCRAPED FINISH OVER A K-REND PRIMER AND BASE COAT (EITHER K-REND BASE COAT OR K-REND SILICONE PRIMER ON BLOCKWORK DIRECT). SILICONE RENDERS ARE FLEXIBLE (CRACK-RESISTANT), HIGHLY WATER-REPELLENT (HYDROPHOBIC — WATER BEADS ON THE SURFACE), AND SELF-CLEANING (CONTAMINANTS WASH OFF IN RAIN). POPULAR COLOURS FOR LONDON EXTENSIONS: BRILLIANT WHITE (THE MOST COMMON CHOICE — CRISP CONTRAST TO YELLOW STOCK BRICK). LIGHT GREY OR STONE GREY (SOFTER CONTRAST, BETTER ON CONSERVATION AREA PROPOSALS WHERE A STARK WHITE MAY BE LESS SYMPATHETIC). ANTHRACITE GREY (FOR CONTEMPORARY LONDON EXTENSION DESIGN — POPULAR WITH DARK ALUMINIUM WINDOWS AND DOORS). K-REND SYSTEM (RENDER BOARD BASE COAT + TC15 TOP): £30 TO £50 PER M² SUPPLY AND APPLY, PLUS SURFACE PREPARATION.

WEBER RENDER SYSTEMS: WEBER ONE COAT PRAL M (HYDRAULIC LIME RENDER — FOR PERIOD PROPERTIES WHERE A LIME-COMPATIBLE FINISH IS REQUIRED ON THE EXTENSION TO MATCH ORIGINAL LONDON TERRACE RENDERS). WEBER PREMIUM MINERAL RENDER (BASE COAT + SILICONE TOP COAT — SIMILAR PERFORMANCE TO K-REND TC15).

NATURAL AND ENGINEERED TIMBER CLADDING IS INCREASINGLY USED ON LONDON REAR EXTENSIONS AS AN ALTERNATIVE TO BRICK OR RENDER — PARTICULARLY FOR CONTEMPORARY ARCHITECTURAL DESIGNS WHERE A WARM NATURAL MATERIAL IS DESIRED.

CEDAR FIBRE CEMENT WEATHERBOARDING (CEDRAL CLICK — THE MOST WIDELY SPECIFIED "TIMBER-LOOK" CLADDING ON LONDON EXTENSION PROJECTS): CEDRAL CLICK (BY ETERNIT/ETEX GROUP) IS A CEMENT-FIBRE WEATHERBOARD IN A HORIZONTAL LAP BOARD PROFILE — AVAILABLE IN WHITE, GREY, ANTHRACITE, CEDAR-EFFECT, AND SMOOTH OR WEATHERED TEXTURE. CEDRAL IS NOT TIMBER — IT IS A FIBRE CEMENT COMPOSITE THAT LOOKS LIKE TIMBER WEATHERBOARD BUT IS DIMENSIONALLY STABLE, DOES NOT ROT OR WARP, AND IS VIRTUALLY MAINTENANCE-FREE. FIRE CLASSIFICATION: CEDRAL CLICK IS CLASS 0 FIRE RATED (NON-COMBUSTIBLE) — UNLIKE REAL TIMBER CLADDING. THIS IS IMPORTANT FOR LONDON EXTENSIONS CLOSE TO BOUNDARIES WHERE PART B FIRE SPREAD REGULATIONS MAY RESTRICT COMBUSTIBLE EXTERNAL CLADDING.

SIBERIAN LARCH (THE PREMIUM NATURAL TIMBER CLADDING CHOICE FOR LONDON EXTENSION PROJECTS): SIBERIAN LARCH (LARIX SIBIRICA) IN HORIZONTAL PROFILE (SHADOW GAP, SHIPLAP, OR OPEN JOINT) IS POPULAR FOR HIGH-SPECIFICATION LONDON REAR EXTENSION AND LOFT DORMER CLADDING. SIBERIAN LARCH IS NATURALLY DURABLE (CLASS 3 DURABILITY — 10 TO 25 YEARS EXPECTED LIFE WITHOUT TREATMENT IN ABOVE-GROUND CLADDING USE). IT WEATHERS TO A SILVER-GREY PATINA OVER 2 TO 5 YEARS IF LEFT UNTREATED — MANY LONDON ARCHITECTS SPECIFY UNTREATED LARCH FOR THIS NATURAL SILVER-GREY FINISH.

THERMOWOOD (HEAT-TREATED PINE OR ASH — IMPROVED DURABILITY FOR LONDON CLADDING): THERMOWOOD IS PINE OR ASH MODIFIED BY HIGH-TEMPERATURE STEAM TREATMENT (185 TO 215°C) — THE PROCESS REDUCES MOISTURE CONTENT AND IMPROVES DIMENSIONAL STABILITY AND DURABILITY (CLASS 2 ABOVE GROUND). AVAILABLE IN CLADDING PROFILES FROM THERMOWOOD GROUP AND UK DISTRIBUTORS.

FOR HIGHER-SPECIFICATION LONDON EXTENSION PROJECTS — PARTICULARLY WHERE LONGEVITY, MINIMAL MAINTENANCE, AND ARCHITECTURAL PRECISION ARE PRIORITIES — HIGH-PERFORMANCE COMPOSITE PANEL CLADDING IS SPECIFIED.

TRESPA METEON (HIGH-PRESSURE LAMINATE HPL COMPOSITE PANEL): TRESPA METEON IS A DECORATIVE COMPOSITE PANEL (WOOD FIBRE AND THERMOSETTING RESIN UNDER HIGH PRESSURE — HPL) WITH A DEEP SATIN OR SATIN FINISH, AVAILABLE IN 250+ COLOURS AND DESIGNS INCLUDING WOOD EFFECTS, METALLIC EFFECTS, AND SOLID COLOURS. THICKNESS: 6MM OR 8MM FOR CLADDING APPLICATIONS. FIXED ON A VENTILATED RAINSCREEN SYSTEM (ALUMINIUM SUBFRAME RAILING WITH STAINLESS STEEL MECHANICAL FIXINGS) — PROVIDES A VENTILATED CAVITY BETWEEN THE PANEL AND THE WALL INSULATION. UV-RESISTANT (EXTERIOR GRADE ACRYLIC TRESPA COATING), IMPACT-RESISTANT, EASY TO CLEAN. FIRE CLASSIFICATION: B-S1,D0 (EUROCLASS) — SUITABLE FOR MOST RESIDENTIAL APPLICATIONS IN LONDON.

ROCKPANEL WOODS (MINERAL WOOL COMPOSITE PANEL — NATURAL STONE/WOOD EFFECT): ROCKPANEL WOODS IS A COMPRESSED ROCKWOOL MINERAL WOOL PANEL WITH A FACTORY-APPLIED DECORATIVE FOIL IN WOOD-GRAIN PATTERNS. CLASS A2 FIRE RATED (NON-COMBUSTIBLE) — SUITABLE FOR ALL LONDON BUILDINGS INCLUDING THOSE NEAR BOUNDARIES. AVAILABLE IN 6MM AND 8MM THICKNESS.

EQUITONE FIBRE CEMENT PANEL (CONTEMPORARY ARCHITECTURAL FACADE): EQUITONE (BY ETERNIT) IS A THROUGH-COLOURED FIBRE CEMENT FLAT PANEL IN MATT GREY, TEXTURA, OR NATURA SURFACES — POPULAR FOR CONTEMPORARY LONDON EXTENSION DESIGNS WITH CRISP, MINIMAL AESTHETICS. 8MM THICKNESS, MECHANICALLY FIXED ON VENTILATED SUBFRAME.

THE CHOICE OF EXTERNAL CLADDING MATERIAL FOR A LONDON EXTENSION IS A PLANNING MATTER IN MANY SITUATIONS — ESPECIALLY IN CONSERVATION AREAS AND ARTICLE 4 DIRECTIONS.

CONSERVATION AREA CONSIDERATIONS: IN LONDON CONSERVATION AREAS (COVERING LARGE PARTS OF ISLINGTON, HACKNEY, CAMDEN, HAMMERSMITH, KENSINGTON, LAMBETH, SOUTHWARK, AND OTHER INNER LONDON BOROUGHS), THE PRINCIPLE OF "APPROPRIATE MATERIALS AND DESIGN THAT RESPECTS THE CHARACTER OF THE AREA" APPLIES. REAR EXTENSIONS ON REAR ELEVATIONS THAT ARE NOT VISIBLE FROM THE PUBLIC HIGHWAY ARE GENERALLY GIVEN MORE DESIGN FLEXIBILITY — CONTEMPORARY MATERIALS SUCH AS SILICONE RENDER, CEDRAL, OR TRESPA ON A REAR EXTENSION ARE OFTEN APPROVED IN CONSERVATION AREAS WHERE THEY CANNOT BE SEEN FROM THE STREET. FRONT ELEVATIONS IN CONSERVATION AREAS ARE MUCH MORE RESTRICTED — MATERIALS VISIBLE FROM THE PUBLIC HIGHWAY MUST TYPICALLY MATCH THE ORIGINAL BUILDING FABRIC (BRICK, LIME RENDER, TIMBER PAINTED WINDOWS).

ARTICLE 4 DIRECTIONS: SOME LONDON BOROUGHS (NOTABLY SOUTHWARK, HACKNEY, ISLINGTON, AND CAMDEN) HAVE ARTICLE 4 DIRECTIONS THAT REMOVE CERTAIN PERMITTED DEVELOPMENT RIGHTS — INCLUDING THE RIGHT TO CLAD EXTERNAL WALLS WITH STONE, ARTIFICIAL STONE, PEBBLE DASH, RENDER, TIMBER, PLASTIC OR TILES WITHOUT PLANNING PERMISSION. WHERE AN ARTICLE 4 DIRECTION APPLIES, ANY CHANGE TO THE EXTERNAL APPEARANCE OF A DWELLING REQUIRES A PLANNING APPLICATION — EVEN IF THE CLADDING IS ON A REAR ELEVATION.

EXTERNAL CLADDING COSTS FOR LONDON EXTENSIONS VARY WIDELY BY MATERIAL AND INSTALLATION COMPLEXITY.

BRICK SLIPS (IBSTOCK RECLAIMED LONDON STOCK EFFECT — SUPPLY AND INSTALL, INCLUDING ADHESIVE, JOINTING, SCAFFOLDING): £80 TO £140 PER M² SUPPLY AND INSTALL.

SILICONE RENDER (K-REND TC15 OR WEBER PREMIUM — SUPPLY AND APPLY PER M²): £30 TO £55 PER M² SUPPLY AND APPLY (EXCLUDING SCAFFOLDING).

CEDAR CLICK FIBRE CEMENT WEATHERBOARD (CEDRAL — SUPPLY AND INSTALL ON VENTILATED BATTEN SYSTEM): £50 TO £90 PER M² SUPPLY AND INSTALL.

SIBERIAN LARCH HORIZONTAL CLADDING (SUPPLY AND INSTALL ON VENTILATED BATTEN SYSTEM): £60 TO £100 PER M² SUPPLY AND INSTALL.

TRESPA METEON HPL PANEL (SUPPLY AND INSTALL ON ALUMINIUM RAINSCREEN SUBFRAME): £120 TO £200 PER M² SUPPLY AND INSTALL.

ROCKPANEL WOODS OR EQUITONE FIBRE CEMENT PANEL (SUPPLY AND INSTALL): £100 TO £170 PER M² SUPPLY AND INSTALL.

TYPICAL LONDON SINGLE-STOREY REAR EXTENSION EXTERNAL FACADE (APPROXIMATELY 15 TO 20 M² CLAD AREA): BRICK SLIPS: £1,200 TO £2,800. SILICONE RENDER: £450 TO £1,100. CEDRAL CLICK: £750 TO £1,800. TRESPA METEON: £1,800 TO £4,000.