Patio roofs, conservatories and carports: one request

A patio roof is usually a frame fixed to the house wall and supported on posts, with a roof of polycarbonate sheet or glass. Aluminium frames are powder-coated, need little maintenance and allow wide spans; timber frames look warmer but need treatment and more posts. Glass roofs let in more light and last longer than polycarbonate, but they are heavier and need a stronger frame.

Louvred roofs have motorised aluminium blades that open for air and close against rain. They cost more, need a power supply and depend on a well-designed gutter in the frame, because rain running off closed blades collects fast. Side screens, glass sliding walls, heaters and lighting can be added, but every addition that encloses the space moves it closer to being treated like a building.

A conservatory has a glazed roof and largely glazed walls; an orangery has more solid wall and often a flat roof with a lantern. Both can overheat in summer and lose heat in winter, so glazing specification, ventilation and blinds matter as much as the frame. Many older conservatories with polycarbonate roofs are now fitted with solid or tiled replacement roofs, which changes the structure and usually needs Building Regulations approval.

In England and Wales, some small ground-level extensions are exempt from Building Regulations. The exemption covers a conservatory, porch or covered way, or a carport open on at least two sides, where the floor area of the extension does not exceed 30 m². For a conservatory, the Planning Portal adds conditions: it must be single storey and at ground level, separated from the house by external-quality walls, doors or windows, with independent heating and its own controls if it is heated.

Glazing and any fixed electrical installation must still comply with the regulations, even if the structure is exempt. Knocking through the house wall to open the conservatory into a room needs Building Regulations approval, because it removes the thermal separation and creates a structural opening. Once that happens, the space is treated as an extension. Scotland and Northern Ireland have their own building standards.

Source: planningportal.co.uk

The Planning Portal says a conservatory falls within the same planning rules as any other home extension, so it may be permitted development in England if it keeps within the limits on size, height and position. A roof attached to the house over a patio is generally assessed in the same way; a freestanding cover or carport is assessed more like an outbuilding. Anything in front of the principal elevation facing the road, on a listed building, or on designated land such as a conservation area is more likely to need an application.

Flats and maisonettes do not have householder permitted development rights. If your house has had earlier extensions, their size counts towards the limits too. A supplier who does this regularly should check the position before quoting and tell you when an application or a Lawful Development Certificate is advisable.

The structure has to cope with wind and snow loads for your location, so ask what loads the system is designed for. Rainwater from the new roof has to go somewhere: into an existing downpipe, a new drain or a soakaway. Fixing to the house wall needs sound masonry and a proper flashing where the roof meets the wall; a bad joint here lets water into the house.

• frame material, colour and roof covering (glass type or polycarbonate thickness)
• dimensions, number and position of posts
• footings for posts and base for a conservatory
• wall connection, flashing and guttering, and where rainwater drains
• electrics: lighting, heaters, motor for louvres, and who certifies them
• planning and Building Regulations position, in writing

Your request describes the space and what you want over it. After you confirm your phone and email, we offer it to suppliers and installers in your area without showing who you are. Exactly one company can buy it, and it pays Offrano; you pay nothing. Before your details are released, we email you the company's name, address and phone number.

Nobody is obliged to buy the request, and it is withdrawn after 21 days if nobody does. You decide whether to accept any quote. We check that the buyer is a registered business; we do not assess its installations, so ask to see finished projects and check who is responsible for planning and Building Regulations.