Pergolas, Gazebos, and Garden Structures for London Victorian Terraces: Timber and Aluminium

TIMBER PERGOLAS ARE THE MOST COMMON CHOICE FOR LONDON VICTORIAN TERRACE REAR GARDENS — LOWER COST, VISUALLY WARM AND SYMPATHETIC TO THE EXISTING BRICK PROPERTY, AND WELL-SUITED TO GROWING CLIMBING PLANTS (WISTERIA, CLEMATIS, ROSES, JASMINE — ALL COMMON IN LONDON TERRACE GARDENS).

TIMBER OPTIONS FOR LONDON PERGOLA CONSTRUCTION: PRESSURE-TREATED SOFTWOOD (TREATED PINE OR REDWOOD — TANALITH E OR TANATONE GREEN): THE MOST AFFORDABLE AND WIDELY AVAILABLE OPTION FOR A LONDON TERRACE PERGOLA. A STANDARD PERGOLA (3M X 3M — 4 POSTS AND OVERHEAD BEAMS): TYPICALLY CONSTRUCTED FROM 100X100MM POSTS AND 150X50MM RAFTERS, PRE-TREATED TO UC3 OR UC4 FOR EXTERNAL USE. LIFESPAN: 15-25 YEARS WITH ANNUAL TREATMENT (BARRETTINE PREMIER WOOD PRESERVATIVE OR CUPRINOL GARDEN SHADES). EUROPEAN OAK (QUERCUS ROBUR — AIR-DRIED, NOT KILN-DRIED): OAK IS THE PREMIUM TIMBER CHOICE FOR A LONDON TERRACE PERGOLA — NATURALLY DURABLE (DURABILITY CLASS 2 — EXPECTED LIFESPAN 25+ YEARS WITHOUT PRESERVATIVE TREATMENT IN ABOVE-GROUND APPLICATION), SILVERING TO A SOFT GREY OVER TIME (POPULAR IN LONDON HERITAGE CONSERVATION AREA GARDENS WHERE AN AUTHENTIC MATERIAL IS PREFERRED). TYPICAL SECTION SIZES: 150X150MM POSTS, 200X50MM RAFTERS — OAK'S HIGHER DENSITY AND STRENGTH ALLOWS LONGER SPANS (UP TO 3.5M RAFTER SPAN WITHOUT INTERMEDIATE SUPPORT). SIBERIAN LARCH (LARIX SIBIRICA — A POPULAR LONDON LANDSCAPE ARCHITECT CHOICE FOR MODERN GARDENS): NATURALLY DURABLE (CLASS 3), RESINOUS, SILVER-GREY FINISH WHEN UNCOATED. AVAILABLE FROM RUSSWOOD, VASTERN TIMBER, ARBOR FOREST PRODUCTS.

PERGOLA POST FOUNDATIONS IN LONDON CLAY: LONDON CLAY IS AN EXPANSIVE AND SHRINK-SWELL SOIL — SHALLOW POST HOLES RISK HEAVE IN WET WEATHER OR SETTLEMENT IN DROUGHT. MINIMUM FOUNDATION DEPTHS FOR LONDON CLAY: 600MM MINIMUM FOR A LIGHT TIMBER PERGOLA. 900MM RECOMMENDED FOR A LARGE PERGOLA (>4M SPANS) OR WHERE PLANTED CLIMBING PLANTS ADD SIGNIFICANT WIND LOAD. CONCRETE MIX: POSTCRETE (TARMAC POSTCRETE OR ST GOBAIN SWIFT-MIX) POURED AROUND POST IN HOLE AND ALLOWED TO SET — FASTER THAN STANDARD READY-MIX. ALTERNATIVE: BOLT-DOWN POST BASES (SIMPSON STRONG-TIE ABA SERIES OR SIMPSON TITAN BOLT-DOWN POST BASE) FIXED TO A CONCRETE PAD (150MM THICKNESS, 300X300MM PLAN — MINIMUM FOR POST BASE) — PREFERRED BY MANY LONDON LANDSCAPERS AS IT ALLOWS POST REPLACEMENT WITHOUT DIGGING OUT CONCRETE.

ALUMINIUM PERGOLA SYSTEMS — AND SPECIFICALLY BIOCLIMATIC LOUVRED ROOF PERGOLAS — ARE AN INCREASINGLY POPULAR CHOICE FOR LONDON VICTORIAN TERRACE REAR GARDENS WHERE THE OWNERS WANT A HIGH-SPECIFICATION OUTDOOR ROOM THAT PROVIDES WEATHER PROTECTION AND CAN BE USED YEAR-ROUND.

WHAT IS A BIOCLIMATIC PERGOLA: A BIOCLIMATIC PERGOLA HAS A ROOF COMPOSED OF ALUMINIUM LOUVRES (TYPICALLY 200-250MM WIDE) THAT CAN ROTATE FROM FULLY OPEN (0° — FULL SUN) TO FULLY CLOSED (90° — RAIN PROTECTION). THE LOUVRES ARE ACTUATED ELECTRICALLY (LOW VOLTAGE DC MOTOR — SOMFY RTS SYSTEM OR BRAND-SPECIFIC CONTROLLER) AND CAN BE CONTROLLED BY APP, REMOTE, OR WEATHER STATION (AUTO-CLOSE IN RAIN, AUTO-OPEN AT TEMPERATURE THRESHOLD). LEADING BIOCLIMATIC PERGOLA BRANDS FOR LONDON RESIDENTIAL MARKET: LLAZA (SPAIN — WIDELY AVAILABLE IN LONDON): THE LLAZA BIOCLIMATIC PERGOLA (ALUMINIUM POWDER COAT RAL 7016 ANTHRACITE GREY — THE MOST POPULAR COLOUR FOR LONDON TERRACE GARDENS) IS AVAILABLE THROUGH UK DISTRIBUTORS (SUNS LIFESTYLE, TRURO). 4M X 3M FREESTANDING BIOCLIMATIC PERGOLA: SUPPLY ONLY: £5,000 TO £9,000. SUPPLY AND INSTALL: £7,000 TO £14,000. RENSON CAMARGUE (BELGIUM — THE PREMIUM END OF THE LONDON MARKET): THE RENSON CAMARGUE IS A VENTILATED LOUVRED ROOF SYSTEM — EACH LOUVRE HAS A BUILT-IN DRAINAGE CHANNEL (RAIN WATER DRAINS THROUGH HOLLOW LOUVRES TO THE POSTS AND AWAY TO GROUND DRAINAGE). PRICE: £12,000 TO £25,000+ FOR 4M X 3M SUPPLY AND INSTALL IN LONDON. PALRAM CANOPIA FERIA (POLYCARBONATE ROOF ATTACHED PERGOLA — THE AFFORDABLE COVERED STRUCTURE ALTERNATIVE): NOT A BIOCLIMATIC SYSTEM — A FIXED POLYCARBONATE ROOF (4MM OPAL OR CLEAR MULTIWALL POLYCARBONATE) ON AN ALUMINIUM FRAME. PROVIDES RAIN COVER AND UV REDUCTION. 3M X 3M PALRAM FERIA: £600 TO £1,200 SUPPLY (SELF-ASSEMBLY). INSTALLATOIN: £400 TO £800 ADDITIONAL.

BEYOND THE OVERHEAD PERGOLA STRUCTURE, MANY LONDON VICTORIAN TERRACE GARDENS INCORPORATE TRELLIS, VERTICAL SCREENING PANELS, AND BOUNDARY STRUCTURES FOR PRIVACY FROM NEIGHBOURING PROPERTIES — A SIGNIFICANT CONSIDERATION IN THE TIGHTLY PACKED LONDON TERRACE GARDEN CONTEXT WHERE OVERLOOKING FROM ADJACENT WINDOWS AND REAR ADDITIONS IS COMMON.

TIMBER TRELLIS AND VERTICAL SCREENING: HARTWOOD QUALITY TRELLIS (PRESSURE-TREATED SOFTWOOD — ROWLINSON GARDEN PRODUCTS OR JACKSONS FENCING PREMIUM TRELLIS): A SIMPLE DIAGONAL OR SQUARE-PATTERN TIMBER TRELLIS PANEL (1800X600MM, 1800X900MM) FIXED TO EXISTING FENCE POSTS OR MASONRY — THE LOWEST-COST PRIVACY OPTION. JACKSONS FENCING PREMIUM FEATHERBOARD FENCE WITH DECORATIVE TRELLIS TOPPER: JACKSONS FENCING SUPREME FEATHERBOARD (JAKCURED PRESSURE TREATMENT — 25-YEAR GUARANTEE) WITH A 300MM OR 600MM TRELLIS TOPPER ABOVE A SOLID 1500MM OR 1800MM FEATHERBOARD PANEL — A COMMON SOLUTION FOR LONDON TERRACE GARDENS WHERE THE MAIN FENCE PROVIDES PRIVACY AND THE TRELLIS TOP ALLOWS CLIMBING PLANTS TO INCREASE HEIGHT WITHOUT REQUIRING PLANNING PERMISSION FOR A TALLER SOLID FENCE.

COMPOSITE OR ALUMINIUM SCREENING PANELS: TREX SECLUSIONS PRIVACY FENCE (COMPOSITE BOARDS — SIMILAR MAINTENANCE-FREE APPROACH TO COMPOSITE DECKING): AVAILABLE IN WINCHESTER GREY OR WINCHESTER SAND — BOARD-ON-BOARD ARRANGEMENT FOR FULL PRIVACY. TOJA GRID SYSTEM (MODULAR ALUMINIUM FRAME ALLOWING COMPOSITE BOARD, TIMBER, OR POLYCARBONATE INFILL — WIDELY USED BY LONDON LANDSCAPE DESIGNERS FOR CLEAN, CONTEMPORARY GARDEN BOUNDARY SCREENING).

HEIGHT LIMITS FOR GARDEN SCREENS WITHOUT PLANNING PERMISSION: UNDER GPDO 2015 PART 2 CLASS A: A FENCE, WALL, OR GATE WITHIN OR ON THE BOUNDARY OF A DWELLINGHOUSE CARTILAGE DOES NOT REQUIRE PLANNING PERMISSION PROVIDED: HEIGHT DOES NOT EXCEED 1M WHERE IT IS ADJACENT TO A HIGHWAY (FRONT GARDEN IN MOST CASES). HEIGHT DOES NOT EXCEED 2M ELSEWHERE (SIDE AND REAR GARDEN BOUNDARIES). A PERGOLA TRELLIS TOPPER ABOVE AN EXISTING FENCE: IF THE TOTAL HEIGHT (FENCE + TRELLIS) EXCEEDS 2M AT THE REAR BOUNDARY, A HOUSEHOLDER PLANNING APPLICATION IS TECHNICALLY REQUIRED — BUT MANY LONDON BOROUGHS GRANT PERMISSION FOR OPEN TRELLIS TOPPERS (AS OPPOSED TO SOLID FENCING) UP TO 2.5M AS THEY DO NOT MATERIALLY AFFECT VISUAL AMENITY.

PLANNING PERMISSION FOR GARDEN STRUCTURES (PERGOLAS, GAZEBOS, SHEDS, SUMMER HOUSES) IN LONDON VICTORIAN TERRACE GARDENS IS GOVERNED BY THE TOWN AND COUNTRY PLANNING (GENERAL PERMITTED DEVELOPMENT) ORDER 2015 (GPDO 2015) — CLASS E OF PART 1 (BUILDINGS, ENCLOSURES, POOLS, AND CONTAINERS WITHIN THE CURTILAGE OF A DWELLINGHOUSE).

CLASS E PERMITTED DEVELOPMENT CONDITIONS FOR GARDEN STRUCTURES: THE STRUCTURE MUST NOT BE BUILT FORWARD OF THE PRINCIPAL ELEVATION (FRONT OF THE HOUSE) — I.E. MUST BE IN THE REAR OR SIDE GARDEN. MAXIMUM HEIGHT: 2.5M IF THE STRUCTURE IS WITHIN 2M OF A BOUNDARY. MAXIMUM HEIGHT: 4M (DUAL-PITCHED ROOF) OR 3M (ANY OTHER ROOF) IF MORE THAN 2M FROM ALL BOUNDARIES. THE STRUCTURE MUST NOT COVER MORE THAN 50% OF THE TOTAL GARDEN/CURTILAGE AREA (COMBINED WITH ANY OTHER EXTENSIONS AND OUTBUILDINGS) — FOR MOST LONDON VICTORIAN TERRACE REAR GARDENS (TYPICALLY 40-80M² TOTAL REAR GARDEN), THIS MEANS THE COMBINED FOOTPRINT OF ALL OUTBUILDINGS AND EXTENSIONS MUST NOT EXCEED 20-40M². A GARDEN STRUCTURE THAT IS USED PRIMARILY FOR HUMAN HABITATION (GARDEN OFFICE, STUDIO, ANNEX) IS TREATED DIFFERENTLY FOR PLANNING PURPOSES — IF IT IS USED AS A SELF-CONTAINED DWELLING (WITH SLEEPING AND COOKING FACILITIES), IT MAY REQUIRE A SEPARATE PLANNING APPLICATION AS A NEW DWELLING.

LISTED BUILDINGS AND CONSERVATION AREAS: IN A LONDON CONSERVATION AREA (WHICH COVERS A VERY HIGH PROPORTION OF VICTORIAN TERRACED HOUSING STOCK), PD RIGHTS ARE NOT WITHDRAWN FOR REAR GARDEN STRUCTURES UNDER CLASS E — THEREFORE A TIMBER PERGOLA IN THE REAR GARDEN OF A LONDON VICTORIAN TERRACE IN A CONSERVATION AREA IS GENERALLY PERMITTED DEVELOPMENT AND DOES NOT REQUIRE PLANNING PERMISSION, PROVIDED THE CLASS E LIMITATIONS ARE MET. LISTED BUILDING: FOR A LISTED LONDON VICTORIAN TERRACE (GRADE II — MOST COMMON LISTING FOR LONDON TERRACES), ANY WORKS WITHIN THE CURTILAGE OF THE LISTED BUILDING MAY REQUIRE LISTED BUILDING CONSENT — CHECK WITH THE RELEVANT LONDON BOROUGH CONSERVATION OFFICER BEFORE PROCEEDING.

PERGOLA AND GARDEN STRUCTURE COSTS IN LONDON VARY WIDELY DEPENDING ON MATERIAL, SIZE, AND SPECIFICATION.

TIMBER PERGOLA SUPPLY AND INSTALL (LONDON — 3M X 3M, 4 POSTS, OVERHEAD BEAMS): PRESSURE-TREATED SOFTWOOD (TANALISED): SUPPLY (TIMBER, HARDWARE, POST BASES OR CONCRETE, DECKING SCREWS): £300 TO £700. INSTALLATION (LANDSCAPE CARPENTER — LONDON RATES): £400 TO £800. TOTAL: £700 TO £1,500. EUROPEAN OAK PERGOLA (3M X 3M — BESPOKE JOINERY): SUPPLY (OAK TIMBER, MORTICE AND TENON JOINTS, BESPOKE FABRICATION): £1,500 TO £4,000. INSTALLATION: £500 TO £1,200. TOTAL: £2,000 TO £5,200.

BIOCLIMATIC ALUMINIUM LOUVRED-ROOF PERGOLA (LONDON — 4M X 3M, FREESTANDING, POWDER-COAT ANTHRACITE, ELECTRIC LOUVRES): SUPPLY: £5,000 TO £9,000 (MID-MARKET — LLAZA, PALRAM, GIBUS). £10,000 TO £20,000+ (PREMIUM — RENSON CAMARGUE, WEINOR TERRAZZA, CORRADI). INSTALLATION: £1,500 TO £3,000. TOTAL (MID-MARKET): £6,500 TO £12,000. TOTAL (PREMIUM): £11,500 TO £23,000+.

POLYCARBONATE-ROOF ATTACHED LEAN-TO PERGOLA (LONDON — 3M X 3M, ALUMINIUM FRAME, 16MM OPAL MULTIWALL POLYCARBONATE): SUPPLY AND INSTALL: £1,200 TO £3,500.

TRELLIS SCREENING (LONDON — PER METRE RUN OF BOUNDARY, 1800MM FEATHERBOARD + 600MM TRELLIS TOPPER — JACKSONS FENCING — SUPPLY AND INSTALL): £120 TO £250 PER METRE RUN.

LARGER GARDEN STRUCTURES IN LONDON VICTORIAN TERRACE REAR GARDENS OFTEN INVOLVE MORE THAN JUST THE STRUCTURE ITSELF — PARTICULARLY WHERE ELECTRICITY SUPPLY, DRAINAGE, AND ADEQUATE FOUNDATIONS ARE NEEDED.

ELECTRICAL SUPPLY TO GARDEN STRUCTURES: IF THE PERGOLA OR GARDEN STRUCTURE REQUIRES ELECTRIC LIGHTING (LED DOWNLIGHTS IN PERGOLA POSTS OR OVERHEAD RAILS — GU10 IP65 DOWNLIGHTS ARE THE STANDARD LONDON GARDEN SPECIFICATION), POWER SOCKETS (FOR OUTDOOR SPEAKERS, HEAT LAMPS, KITCHEN EQUIPMENT IN AN OUTDOOR KITCHEN CONTEXT), OR ELECTRIC LOUVRE ACTUATION (FOR BIOCLIMATIC PERGOLA SYSTEMS), A DEDICATED GARDEN CIRCUIT IS REQUIRED. PART P NOTIFICATION: THE INSTALLATION OF A NEW OUTDOOR ELECTRICAL CIRCUIT FROM THE CONSUMER UNIT IS A NOTIFIABLE WORK UNDER PART P — AN NICEIC OR NAPIT REGISTERED ELECTRICIAN IS REQUIRED. ARMOURED CABLE: SWA (STEEL-WIRE ARMOURED) CABLE (2.5MM² 3-CORE — PYROTENAX SWA OR DRAKA SWA) SHOULD BE USED FOR THE UNDERGROUND RUN FROM THE HOUSE TO THE GARDEN STRUCTURE — LAID AT 600MM DEPTH (MINIMUM) IN LONDON CLAY, MARKED WITH CABLE MARKER TILES.

GARDEN DRAINAGE FOR COVERED STRUCTURES: A COVERED PERGOLA (BIOCLIMATIC LOUVRED ROOF, POLYCARBONATE ROOF, OR GLASS ROOF) CONCENTRATES RAINWATER FROM THE ROOF AREA INTO A SMALLER DISCHARGE AREA — IF NOT CORRECTLY DRAINED, THIS CAN CAUSE FLOODING OF THE GARDEN, WATERLOGGING OF PLANTING, AND SPLASH-BACK ONTO THE HOUSE FOUNDATION. ACO BRICKSLOT DRAINAGE (LINEAR CHANNEL — STAINLESS STEEL BRICKSLOT GRATING — THE MOST VISUALLY REFINED DRAINAGE SOLUTION FOR COVERED LONDON TERRACE GARDENS): CHANNEL INSTALLED AT THE PERIMETER OF THE COVERED AREA TO INTERCEPT ROOF RUNOFF BEFORE IT REACHES THE GARDEN SURFACE. DISCHARGE: TO SOAKAWAY (POLYPIPE SOAKAWAY CRATE — 800X400X400MM — MINIMUM 5M FROM THE BUILDING AND FILLED WITH PEA GRAVEL) OR TO EXISTING GARDEN DRAINAGE. IN LONDON, SURFACE WATER DISCHARGE TO THE PUBLIC SEWER IS TECHNICALLY RESTRICTED FOR NEW DISCHARGE POINTS — THE PREFERRED APPROACH IS SOAKAWAY OR ATTENUATION.