Pergolas & Garden Structures: Cost & Planning

A pergola can transform a garden, providing shade, structure for climbing plants, and a defined outdoor room that extends the usable season by weeks. But with costs ranging from a few hundred pounds for a timber kit to several thousand for a motorised louvred structure, and planning rules that catch out many homeowners, it pays to understand your options before buying.

How Much Does a Pergola Cost?

Cost depends primarily on material, size, specification, and whether you are fitting it yourself or paying for installation.

These are retailers’ own prices for one named pergola of each kind, in October 2026. Hardwood, fixed-roof aluminium and bespoke steel pergolas are priced by quote, and no retailer publishes a fitted price for them.

A pressure-treated softwood kit is the cheapest route: Wickes sells the Forest Garden Ultima pergola, 3.6 × 3.6 m, at £561.¹

Tiger Sheds sells its 3.3 × 3.3 m Trellus timber pergola at £1,175.99, including VAT.²

Its own fitters will erect it for £315.²

A motorised louvred aluminium pergola, 3 × 4 m with LED lighting and electrically adjustable slats, is £2,099 from a seller on B&Q’s marketplace, as a kit.³

Installation cost beyond that depends on the complexity of the foundations, whether the structure is freestanding or wall-attached, and access to the site.

Types of Pergola and Garden Structure

Timber Pergolas

The traditional choice, open rafters on vertical posts, typically providing dappled shade through the structure. Softwood (pressure-treated Scandinavian redwood or pine) is the budget option; it requires painting or staining every 2–5 years and has a lifespan of 15–25 years with reasonable maintenance. Hardwood (oak, western red cedar, iroko) is more expensive but largely maintenance-free and can last 40+ years. Oak weathers to a silver-grey naturally; many homeowners prefer this.

Best for: Traditional or cottage gardens; climbing plants (wisteria, roses, clematis); those on a tighter budget.

Aluminium Pergolas (Fixed Roof)

Powder-coated aluminium with a polycarbonate, glass, or solid aluminium roof panel. These are weatherproof and essentially maintenance-free but have a more contemporary, utilitarian appearance. Many systems are modular and can be extended.

Best for: Year-round use; low-maintenance requirement; modern or Scandinavian-style gardens.

Bioclimatic Louvred Pergolas

The premium option, motorised rotating louvres in the roof that open for sun, close for rain, and adjust for ventilation. Typically aluminium, available in RAL colours, with optional integrated LED lighting, heating elements, and retractable side screens. They create a genuinely usable outdoor room for most of the UK year.

Best for: Those who entertain outdoors regularly; south or west-facing gardens with good sun; buyers who want a feature with genuine resale appeal.

Gazebos

A gazebo differs from a pergola in that it typically has a fully enclosed roof (often hexagonal or octagonal) and sometimes fixed or removable sides. Gazebos are more enclosed than pergolas, but the same permitted development limits apply to both.

Summerhouse24 sells a 3 × 3 m timber gazebo, its Gazebo A, at £2,425.⁴

Its installation service adds £1,590.⁴

Sail Shades and Canopies

Not structural, but worth mentioning as the budget alternative. High-quality tensioned sail shades are fixed to anchor points on the house, posts or trees. They are usually taken down in winter and typically last 5–10 years.

Planning Permission Rules for Pergolas

Under the Town and Country Planning (General Permitted Development) Order 2015 (as amended), garden structures including pergolas are permitted development for most residential properties, provided they meet all of the following conditions:

• The structure is within the curtilage of a dwelling house (i.e. the garden of a house, not of a flat or maisonette)
• The structure, together with other outbuildings and enclosures, does not cover more than 50% of the garden (the curtilage, excluding the ground area of the original house)⁵
• The maximum height does not exceed 2.5 metres within 2 metres of a property boundary, or 4 metres with a dual-pitched roof, or 3 metres otherwise, and the eaves are no higher than 2.5 metres⁵
• The structure is not forward of the principal elevation (i.e., not in the front garden)⁵
• The property is not listed, and, in a conservation area, National Park or other protected (article 2(3)) land, the structure is not between a side wall of the house and the boundary⁵

Important nuance: For permitted development purposes a “building” includes any structure or erection, so an open pergola with no roof is treated the same as one with a solid or glazed roof, and the limits above apply either way.⁶ Building Regulations are a separate question: a detached single-storey structure with no sleeping accommodation is exempt if its floor area is no more than 15 m², or no more than 30 m² where it is at least 1 m from the boundary or built substantially of non-combustible material.⁷ A covered way or carport open on at least two sides, added to the house at ground level, is exempt up to 30 m² of floor area.⁷ If in doubt, check with your local planning authority or building control body.

Flats and maisonettes: Permitted development rights for outbuildings do not apply to flats, maisonettes, or houses converted from non-residential use. You will need planning permission.⁸

Foundations for Pergolas

Freestanding pergolas require proper footings, skimping here is the most common cause of structural failure, particularly in exposed locations.

• Timber post spurs or metal post anchors: Suitable for smaller, lighter structures. Post anchors bolt to a concrete pad; spurs are driven or cast into concrete. Cost-effective and allow for post replacement.
• Concrete pad footings: Posts set into 300–450mm diameter holes, 600–750mm deep, concrete-filled. Standard for most timber pergolas. Concrete should cure for at least 7 days before load is applied.
• Helical pile foundations: Used for heavier aluminium or steel structures, particularly on difficult ground. More expensive per footing than concrete pads, but faster and less disruptive than excavation.

Wall-attached pergolas (lean-to pergolas) fix to the house wall via a wall plate or aluminium channel. These must be fixed to the structural element of the wall, not just the render or cladding. Use appropriate fixings for the wall type (brick, block, timber frame), consult a structural engineer if in doubt for larger structures.

Maintenance Requirements by Material

Climbing Plants for Pergolas

The right plants can transform a timber pergola within 2–3 seasons. Top choices for UK gardens:

• Wisteria sinensis: Spectacular in May–June; needs annual pruning to prevent it overwhelming the structure; vigorous, suitable for robust hardwood or aluminium only
• Rosa (climbing varieties): Long flowering season; thorny, account for access; some vigorous varieties (e.g. Rambling Rector) can damage lightweight structures
• Clematis: Lighter and less vigorous than the above; many flower twice; ideal for smaller pergolas
• Lonicera (honeysuckle): Fast-growing, fragrant, wildlife-friendly; most lose their leaves in winter

Allow 3–5 years for most climbers to provide meaningful coverage. Fit galvanised horizontal wires or timber battens to support growth and prevent stems from directly binding around structural posts.

The rules in this note are those that apply in England. Scotland, Wales and Northern Ireland have their own building standards and permitted development rights.