What is an arbour?

An arbour is a light, largely open structure in the garden with a roof over it, built as a sheltered place to sit. The difference from a summerhouse is the openness: an arbour usually has no solid walls, only trellis, balusters or bare posts. The difference from a pergola is the roof: a pergola has only open rafters above, while an arbour has a closed roof plane or a densely grown canopy of trained trees and climbers.

Historically the arbour was a green room: a timber or iron frame over which honeysuckle, grapevine, climbing rose or wisteria was trained. In the eighteenth- and nineteenth-century landscape garden the arbour became a fixture, often octagonal, placed on a sightline or beside a pond.

Types

• Trellis arbour — a timber or steel frame acting as a support for climbing plants
• Octagonal garden pavilion — freestanding, with a pointed roof and open sides
• Wall arbour — semicircular, set against a wall or hedge
• Berceau or pleached walk — a continuous overgrown tunnel; the linear version of the same idea

Building one yourself

1. Foundations. Even a light arbour catches a lot of wind once it is covered in planting. Set the posts on concrete pads or ground screws; an arbour standing only on paving slabs will shift.
2. Posts. For an arbour of roughly 3 x 3 m, use posts of at least 90 x 90 mm; go to 120 x 120 mm for larger spans.
3. Timber choice. Use durability class 1 or 2 (robinia, oak, western red cedar) or pressure-treated softwood. Keep timber at least 100 mm clear of the ground, or use post shoes with a raised base.
4. Roof. For a closed roof: at least 15 degrees of pitch for tiles, around 2 degrees for EPDM or bitumen sheet. Discharge rainwater deliberately, or it will run straight onto the seat below.
5. Cost. A self-built arbour in treated softwood costs roughly €500 to €2,000 in materials, depending on size, timber species and roof covering; a bespoke hardwood pavilion sits well above that.

Permission

Whether an arbour needs planning permission depends on national and local rules — its height, footprint, distance to the boundary and the status of the site all matter, and the thresholds differ by country. Stricter rules apply to listed buildings, conservation areas and anything in front of the building line. Always check with the local planning authority before you build.

Related terms

• Pergola
• Summerhouse
• Durability class
• Post shoe
• Hipped roof

Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.