Conservatory roof replacement

Many conservatories built in the 1990s and 2000s have polycarbonate or early glass roofs. They can leave the room too hot in summer, too cold in winter and noisy in the rain. Replacing the roof is often the way to turn it into a room you use all year.

Your options

A new glass roof. Modern glass roofs use solar-control and low-E coatings to reduce glare and heat build-up while keeping the room bright. Some include a self-cleaning coating. This is the closest to a like-for-like replacement.

Polycarbonate. The cheapest option. Newer multi-wall sheets perform better than old ones, but polycarbonate is still relatively noisy in the rain and doesn't insulate as well as other options. It's usually chosen on cost.

A solid, tiled roof. A lightweight frame with insulation, finished with tiles or slates outside and plaster inside. It can make the room feel much more like part of the house, and some systems include glazed panels or roof windows to keep it light. This is the biggest change.

Insulated panel roofs. Lightweight insulated panels, sometimes combined with glass sections. These sit between a glass roof and a fully tiled one.

When Building Regulations apply

Most conservatories are exempt from Building Regulations, as long as they meet certain conditions. These include being separated from the house by external-quality doors or walls, having their own heating controls, and having a roof that is largely glazed or translucent.

Replacing a glass or polycarbonate roof with a like-for-like glazed roof doesn't normally change that. Replacing it with a solid roof usually does. Once most of the roof is no longer translucent, the room is generally no longer treated as a conservatory, so the new roof normally needs Building Regulations approval.

Building control will usually want to check:

• that the existing base and frames can carry the extra weight of a solid roof
• the insulation, ventilation and structure of the new roof
• fire safety, especially if the conservatory is close to a boundary

Some roof systems have certification that can make approval more straightforward. Your specialist should explain how they'll handle approval and whether it's included in the price. Make sure you receive the completion certificate, as you'll need it when you sell.

Planning permission

Changing the roof of an existing conservatory is often allowed without planning permission, but not always. It may be needed if the change significantly alters the appearance, if materials don't match the house, or if your home is listed or in a conservation area. Check with your council if you're unsure.

Before you decide

• Check the base and frames. If they're in poor condition, replacing the whole conservatory may make more sense than replacing the roof.
• Think about light. A solid roof makes the room cosier but darker. Roof windows or glazed panels can help.
• Think about heating. If you want to connect the room to your main central heating or remove the doors to the house, that also affects the exemption. Ask your specialist.
• Ask about the timescale. Most roof replacements take days rather than weeks, but approval can add time.

Questions to ask

1. What roof system do you recommend for my conservatory, and why?
2. Will my existing base and frames take its weight, and how have you checked?
3. Does it need Building Regulations approval, and who arranges it?
4. Is the cost of approval included in the price?
5. What guarantee comes with the roof and the installation, and is it insurance-backed?

You're always free to compare. Get the price, the specification and the approval arrangements in writing before work starts.