Conservatory cost calculator: what the job involves and who is registered to do it

How conservatory cost calculator works

1. Check that it asks what goes under the room. A calculator that never mentions foundations is pricing frames and glass and calling it a building. Ground conditions, foundation depth, whether a drain crosses the footprint and what the existing house footing is doing are the largest single variable in a conservatory, and no tool that skips them can be within a useful range.
2. Check that it asks about the opening into the house. There is a large and permanent difference between fitting into an existing patio door opening and cutting a new hole in a load bearing wall. The second brings a structural calculation, a lintel, propping and building control. If the tool has no field for it, its output covers only the first case.
3. Check that it is priced for this country. British conservatories are built under the Approved Documents, use the conservatory exemption with its separating doors and floor area conditions, and have their electrical work certified under a competent person scheme. A calculator built for another market is pricing a room that would be built differently here, and that shows up in the roof and the glazing above all.
4. Treat the output as a floor and not a figure. Use a calculator to find out whether you are in the right conversation, then get a measured survey. The number that matters is the one written after somebody has stood in the garden, looked at the wall and asked what the ground is like.

Insurance and paperwork

Common questions

Why will a calculator not give me a fixed price?

Because half its inputs are unknown until a surveyor visits. Ground, the existing wall, drainage and access are site facts rather than choices, and no honest tool pretends to know them from a postcode.

Do calculators include the base and the electrics?

Some do, most do not say. Read what the output claims to cover before you compare it with a quote, because a quote that includes groundworks and certified electrics against a calculator figure that includes neither is not a comparison at all.

Is a supplier's own calculator biased?

It is at least selective. A tool on a seller's site is built to start a conversation, so it tends to price the straightforward case and leave the awkward lines for the survey. That is not dishonest, but it does mean the output is a beginning.

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