Louvred pergolas: a UK buyer’s guide

A louvred pergola, also sold as a bioclimatic pergola, is an aluminium frame with a roof of blades that turn. Open, they let light and air through. Angled, they cut the sun. Closed, they make a roof that keeps off the rain. It turns a patio into an outdoor room you can use for more of the year.

How the louvres work

The roof blades sit side by side and rotate together. Motorised systems turn them with a switch or remote; some can add rain or wind sensors that close or open the roof automatically. Manual systems use a crank or handle.

What happens when it rains

When the blades are closed, they overlap and channel water into gutters built into the frame, which drain down through the posts. That is why the frame size, the number of posts and where the water comes out at ground level should be planned before installation. Ask where the downpipes run and make sure the water has somewhere to go.

Wall-fixed or free-standing

Wall-fixed pergolas are fixed to the house on one side and stand on posts on the other. They need a solid wall and a clear line under eaves, gutters and windows.
Free-standing pergolas stand on four or more posts anywhere in the garden or on a terrace, and need a firm base for the post fixings.

Choosing the size

Start with how you will use it. A dining table and chairs needs more depth than a pair of loungers. Lay the furniture out on the patio and measure around it.
Allow for doors and steps. Leave room for doors to open and people to walk through without ducking under a post.
Check the height. Measure from the ground to the lowest point you can fix to on the wall, and look at how close the roof will be to windows and gutters.
Think about the sun. A south or west-facing pergola needs the louvres for shade most; side screens on the low-sun side help in the evening.

Closing the sides

Side screens make a pergola useful in wind and low sun. Zip screens are fabric blinds held in side channels; they cut sun, wind and insects and roll away when not needed. For a room you can close in cooler weather, the sides can be glazed with sliding glass or guillotine glass, and glass windbreaks shelter seating without blocking the view.

Planning permission in England

General guidance, not legal advice. Rules differ in Wales, Scotland and Northern Ireland; your council has the final word.

Many garden pergolas are treated like other garden structures under permitted development. The limits you will most often meet are on height (lower limits apply close to a boundary), on how much of the garden is covered, and that the structure should not sit in front of the main face of the house. A pergola fixed to the house may be looked at more like an extension. Listed buildings, conservation areas and flats have stricter rules. Check with your council or the Planning Portal before you order.

Looking after it

Clear leaves from the blades and gutters, especially in autumn.
Wash the aluminium with mild soapy water; avoid abrasive cleaners.
Open the blades in snow, or clear heavy snow, unless the system is rated for the load.

What to ask for in a quote

Overall width, depth and height, and whether it is wall-fixed or free-standing
Manual or motorised louvres, and any rain or wind sensors
Where the water drains and how the posts are fixed to your base
Side screens, glass sides or windbreaks, and on which sides
Lighting, heating and the power supply they need
The frame colour and finish
Whether installation is included, and who prepares the base

Comparing quotes is much easier when every supplier is pricing the same list.

What makes the price go up or down

The main drivers are size, the number of posts, motorisation and sensors, side closures such as zip screens or glass, lighting and heating, and the work needed to prepare the base. A wall-fixed pergola needs fewer posts than a free-standing one of the same size. A simple manual pergola with open sides costs far less than a fully enclosed, motorised outdoor room.

Wind and snow

A pergola has to carry wind and, in some parts of the UK, snow. Ask the supplier what loads the system is designed for, and what to do with the louvres in high winds or heavy snow. Motorised systems with sensors can open or close the louvres automatically when the weather changes.

Questions we are asked

What is the difference between a louvred pergola and a bioclimatic pergola?

They are usually the same product. "Bioclimatic" refers to the way the rotating louvres let you control sun, ventilation and rain.

Is a louvred pergola fully waterproof?

With the blades closed it keeps off rain, and the water drains through the frame. It is not sealed like a room, so wind-driven rain can still reach the sides unless they are closed.