ARTICLE Stephanie Matheson PHOTOGRAPHY Mitre10

A space to relax, to sit in the shade and de-stress - creating your own personal garden sanctuary with a pergola is easy if you keep a few basic points in mind. We've asked building expert Stan Scott from Mitre10 what's involved and what to look out for.

What to be aware of

While most pergolas under 20 square metres (even those that are attached to a house) do not require a building consent, it's best to check with your local council to ensure that regulations haven't changed and you are not infringing on any height-to-boundary or other rules. Also, contact your local utility companies to ensure you are not digging near any utility lines.

Measuring and marking out where the posts for your pergola will go are key steps for the success of your project. A lot of care and time should be taken to ensure the structure is square.

Pergola options

The main point of difference between pergolas is whether they are freestanding or attached to a house. Common materials for pergolas are timber and metal, and you can choose different roof styles. Rafters and battens make up the classic roof structure of timber pergolas, creating an 'open roof' that provides some shade but is otherwise open to the elements. Louvres, retractable fabric sheets and fabric panels are also popular options.

Step 1

Your builder should draw up a proper plan to ensure the pergola is structurally sound. A licensed building practitioner (LBP) has experience in specifying the right dimensions and post sizes. Glue-laminated top quality posts are worth the extra money and will stand the test of time. 

Step 2

Doing the 'groundwork' is critical. Your builder will mark on the ground where the post holes will go, and then build a frame for string lines. He will run several string lines, and needs to ensure they are all level.

Step 3

Now it's time to dig the holes and insert the posts. The holes need to be deep enough, at least 450 to 600 millimetres deep, or as deep as it takes to hit solid ground. The posts need to be placed on top of a concrete block (at least 100 millimetres off the ground), lined up against the string lines and braced. Concrete will be poured in to permanently fix the posts into place. Once it has set the braces, the string lines and the frame can be removed.

Step 4

Once the posts are in place, your builder can cut them to size and cut out the rebates that will hold the bearers in place. He will then measure and cut two bearers and all rafters.

Step 5

Finally, your pergola can be assembled. Bearers will be bolted onto the poles. Rafters will be nailed onto the top, followed by battens that will be nailed across the rafters.

Glossary of terms

Battens

Battens are thin lengths of wood nailed across the rafters (in a 90 degree angle to the rafters) to finish off the 'open roof' look of a standard freestanding timber pergola.

Bearers 

A freestanding wooden pergola typically has two bearers bottled onto two poles each, parallel to each other. They hold the rafters.

Poles

These are the 'legs' of your pergola; a typical freestanding pergola has four posts.

Rafters

Rafters are lengths of wood that are nailed across two bearers in spaced intervals to create the 'open roof' of a standard freestanding timber pergola.

All information is believed to be true at time of publishing and is subject to change.

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