5m x 3m conservatory cost: what the job involves and who is registered to do it

How 5m x 3m conservatory cost works

1. Look at what a five metre elevation does to the house wall. Five metres of frontage rarely lines up with one existing opening. Either the room is served by a single set of doors and the rest of the wall stays blind, which people regret, or the wall is opened up, which is structural work with a calculation, a lintel and building control attached. Decide that before you compare quotes, because one firm may have priced it and another may not.
2. Plan the drainage before the roof. A longer roof sheds more water into fewer places. The quote should say where the rainwater goes: into the existing system, which may not have the capacity, or into a new gully or soakaway. Discharging a new roof into a drain that was sized for a house is the sort of thing that works for two years and then does not.
3. Think about heat before the doors are ordered. At fifteen square metres a conservatory that overheats in summer and freezes in winter is a room you stop using. That is a glazing specification question first, a ventilation question second and only then a heating question. Extending the house heating into the room is the one answer that takes it outside the conservatory exemption.
4. Check the floor area against the exemption. Fifteen square metres is still inside the conservatory exemption, but the margin is narrower than people assume once a base and a threshold are drawn properly. If the design is close to a limit, get it confirmed in writing rather than measured off a brochure drawing.

Insurance and paperwork

Common questions

Is 5m x 3m more expensive per square metre than a smaller room?

Usually less, because the fixed costs are spread further. The catch is that the additional work a five metre elevation tends to trigger, a wider structural opening and new drainage, is not proportional to area and can wipe out the saving.

Do I need a party wall notice for a room this size?

It depends on where it sits rather than how big it is. Excavating for foundations within the distances the Party Wall etc. Act sets out from a neighbour's structure brings the Act into play whatever the room's area, and a conservatory built up to a boundary is a common trigger.

Can a room this size be used as a kitchen or a bathroom?

Not while it relies on the conservatory exemption. Rooms with drainage and fixed appliances are ordinary building work with their own Approved Documents, and designing one as a conservatory to avoid that is how people end up with something they cannot sell.

Registered contractors by region

• Registered roofers in the East Midlands postcode area
• Registered roofers in the East of England postcode area
• Registered roofers in the London postcode area
• Registered roofers in the North East postcode area
• Registered roofers in the North West postcode area
• Registered roofers in the Scotland postcode area
• Registered roofers in the South East postcode area
• Registered roofers in the South West postcode area
• Registered roofers in the Wales postcode area
• Registered roofers in the West Midlands postcode area
• Registered roofers in the Yorkshire and The Humber postcode area