It means each corner is made up by two rails meeting the post rather than one, with heavy-duty corner bracing added at the junction. The practical effect is that wind load and the weight of a roof kit are spread across a wider joint, so the frame resists racking and stays square over the years. It is the main structural difference between this pergola and the standard garden version.

Included. The deck is designed and machined as part of the same structure, in the same pressure-treated redwood and the same finish as the frame, so the boards, the posts and the rails all line up. That saves laying a patio or buying a separate deck kit and then trying to marry the two together. You need firm, level, well drained ground and not much else.

Five square sizes: 2.4m x 2.4m, 3m x 3m, 3.6m x 3.6m, 4.2m x 4.2m and 4.8m x 4.8m, each available in Light Green or Rustic Brown at the same price. Choose the finish on how it will sit against your wall, fencing and planting. If your space falls between two of the stock sizes, custom builds are available and we will quote from your own measurements.

Yes, in one respect. Selecting a roof kit builds a discreet 5 degree pitch into the structure so rainwater runs off the polycarbonate instead of pooling on it. Sheets come in clear, opal or bronze with brown or white glazing bars. Because a roof adds surface for the wind to push against, we recommend fixing the pergola down, either by concreting the posts in or using our bolt-down feet.

Straightforward for two people over a weekend, largely because of the precision notching. The joints are machined before the timber leaves us, so sections drop into place instead of being measured and cut in the garden. Work in sequence: level the ground, lay the decking base, stand and plumb the posts, fix the ledger to the house wall, then add the rails, bracing and rafters before any roof sheets.