How accurate is the estimate vs real quotes?

The calculator produces a range, not a single number. The honest answer to "how accurate is it?" depends on which end of the wizard you stop at.

After Step 5 (initial estimate)

Accuracy: General to Good. The range covers the typical span of UK projects of this property + size + tier in your region. Useful for deciding whether the project is in the right ballpark of your budget. Not yet accurate enough to plan against.

After Step 7 (refined estimate)

Accuracy: Strong to Very Strong. The range has tightened around your specific answers, and the additions/risks panel shows what we found. A real quote from a contractor should land inside or just above the upper end of this range.

How to read a real quote against your range

• Quote lands inside the range → expected. Use it as a fair comparison baseline against other quotes.
• Quote lands well below the lower bound → be cautious. Check the Scope of Works line by line. The contractor is probably leaving out work that the others have included, or assuming you supply materials, or quoting labour-only.
• Quote lands above the upper bound → usually one of: site-specific complications (access, listed building, structural issues), high-end finishes you specified, or the contractor is at full capacity and quoting "if you really want me". Ask them which.

Why we cannot be more precise

Without sending a surveyor to your specific property, no calculator can give you a single number. What we can do is rule out unrealistic numbers (above and below) and make sure every contractor is quoting against the same scope. That is what the Scope of Works document does.