Free estimate, AI estimate or a quotation: which one do you need?

Pricing a building project is not one question but three, asked at different moments. Is this roughly affordable? What will my project cost? And what will a builder charge to build it? Each has its own answer, and at MVV each has its own tool: the free estimate, the AI Estimator and a quotation after a site visit. Here is what each one gives you, what it cannot do, and which to start with.

• The free estimate answers "is this roughly affordable?" A range from typical London jobs like yours, line by line, in about two minutes. Free.
• The AI Estimator answers "what will my project cost?" Your own project, priced trade by trade from your description, photos and plans, on screen and by email in minutes. A one-off fee per estimate, shown before you start.
• A quotation answers "what will it cost to build?" A price for your house, prepared after a site visit, that sets out what is included and what is not. The first consultation is free.

Both estimates are indicative and exclude VAT, and neither is an offer to build: only a quotation is.

Use it at the idea stage, before you spend anything. You choose your home, when it was built and what you are planning, from an extension (rear, side return or L-shaped, on one storey or two) to a loft conversion, a full refurbishment, a kitchen or bathrooms, and a 3D model of your home builds itself as you answer. The range arrives on screen with a reference number, by email, and as a PDF with an illustrative drawing of your home. We walk through each step in How much will my extension cost?

Its limits are honest ones. It prices a typical project of your size and type, not your house, from typical London jobs priced on our estimator in September 2026 and calibrated to inner west London. Some work, such as a mansard or a hip to gable loft, it does not price at all, because the roof itself decides most of the cost: we come back to you with a figure instead.

Use it when the idea has become a plan and you want a budget you can work with. You describe the project in your own words, add photos and plans if you have them, and answer a few sharp questions. It then prices the work trade by trade, from the structure to the last coat of paint, and a realistic range with a breakdown of where the money goes arrives on screen and by email.

The rates come from real projects priced by MVV, a working London design and build contractor, rather than from a published index, and prices are calibrated by postcode area, so it works across England. One payment covers one complete estimate, and if a run fails on our side you can run it again at no charge. It is software by MVV Technologies Limited, used under licence by MVV Construction Ltd.

It is still an estimate: indicative, excluding VAT, and made without anyone seeing the property.

When you are ready to build, you need a price for your house, not a range. A quotation follows a site visit, once the property has been seen. Book a free consultation and we visit the property, talk through your brief and prepare a fully costed proposal.

A proper quotation itemises what is included and, more importantly, what is not: provisional sums, client supplies, VAT and professional fees. Our guide to choosing a building company explains what to look for when you compare them. On a design and build project the same team then takes the job from the feasibility study and design, through planning, to the build and the handover.

The three are designed to be used in that order, and you can start at whichever fits:

• Just wondering what an extension or a loft might cost? Start with the free estimate. It takes about two minutes.
• Planning a budget, or weighing up options such as one storey or two? Price the options with the free estimate, then run the one you prefer through the AI Estimator for a trade by trade breakdown.
• Ready to build, with drawings or a clear brief? Book a consultation and a site visit for a quotation.

Whichever you start with, check what the figure leaves out. Both estimates exclude VAT, and the free estimate also leaves out professional fees, planning and building control fees, and the Community Infrastructure Levy where it applies. A proper quotation lists what it includes and what it does not.