How to Specify a Retractable Awning: Sizing, Wind Class and Motor Selection

A retractable awning is the easiest thing on a terrace to specify and the easiest thing to get wrong. Most of the mistakes we see arrive as an email with a photograph and a width, and end with a cassette that is too small for the fabric or a bracket set that is undersized for the wind exposure.

Start with the projection, not the width

The single most common error is treating the width of the fabric as the width of the unit. They are not the same thing. On a full-cassette awning, the cassette is wider than the fabric by the drop of the roller, and the arms pivot out from a mounting plate that needs its own clearance behind the facade. Specify the full assembly width, and specify the drop separately. A 4-metre fabric on a 4.3-metre cassette on a terrace with a 500 mm bracket projection is a different product from a 4-metre unit mounted flat against the wall.

Match the wind class to the exposure

Every credible awning system is rated for wind, and the rating is only meaningful if it is tied to an exposure category. A unit on an open coastal terrace with nothing above it and a unit fitted below a balcony in a sheltered city street are not the same job, even at identical dimensions. When you quote, state the wind class and the mounting conditions together, and confirm that the fixing points can actually take the reaction. The most common failure we are asked about is not the awning breaking; it is the bracket pulling out of a facade that was never designed to take the load.

Get the motor right

For anything above roughly three metres wide, a motor is not a luxury. Manual systems on large units need a surprising amount of force at the worst moment, and a projection-heavy awning in a breeze is exactly the wrong moment to ask a customer to do it.

• Check the torque rating against the fabric weight and the projection, not just the arm length.
• Decide on limits. Most current motors include a wind sensor or a rain sensor that retracts the awning automatically. In an exposed position that is worth more than any manual override.
• Think about the power supply. Many motors are supplied with a plug and a short lead, which means the socket has to be on the right side of the facade. Specify the lead length with the order, not after installation.
• Confirm the control system. If the unit is going into a project with a home-automation system, the integration protocol needs to be agreed at order stage.

The details that come back later

Mounting plates, drainage, and the quality of the fabric are all specified after the order is placed more often than we would like. Each of them has an answer at order stage, and each of them is expensive to change afterwards. Our drawings and specification sheets show all three, and we would rather you spend ten minutes reading them than we spend a day answering emails about a missing drain.

If you are specifying awnings for a project, send us the facade section and the exposure conditions and we will come back with the unit, the fixings and the wind class, drawn.