Recommended by [practice name].
FREE BUDGET CALCULATOR FROM MULTIPROJECT, RESIDENTIAL QUANTITY SURVEYORS
What will your home project cost?
A free budget calculator for extensions, loft conversions, renovations and new homes. Answer a few questions and get an indicative range for your area.
✓ Only three answers needed: the type of work, a rough size and your postcode
✓ No phone number needed
✓ Your range on screen, then a budget report and fee proposal by email
✓ Only three answers needed: the type of work, a rough size and your postcode
✓ No phone number needed
✓ Your range on screen, then a budget report and fee proposal by email
Who's behind the calculator
Bart Kolosowski MCIArb
A quantity surveyor for over 20 years, Bart helps homeowners plan realistic budgets and co-hosts The Home Project Podcast.
“Great for getting realistic costs before you start and to lower risks.”
Hugh Stirling, homeowner
“They worked directly with our architects to draft a plan that helped us make sense of the costs and all the complexities of the build.”
Benoit Grogan-Avignon
“…allowed me to make informed decisions.”
Arek Palka
From our Google reviews.
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How it works
Answer a few questions.
Tell us the type of work, a rough size and your postcode. You can give the size in square metres or square feet, as measurements, or by the number of bedrooms. The other questions are optional, and "Skip to my figure" takes you straight to the end.
See your range on screen.
Leave your first name and email, and we show an indicative range for the building work, including VAT where it applies and a 10% contingency, adjusted for your region.
Get your budget report and fee proposal.
We email a fuller report: the cost of each part of the work, what moves the price, how we adjusted for your region, what is excluded, and our fixed fees for the services that suit your stage.
The range is an automatic planning figure from your answers. It is not a builder's quotation, a survey or a design cost check of your drawings, and the final cost may fall outside it.
Which help do I need?
Just an idea
Budget Reality Check
Early sketches
Budget Reality Check, or a design cost check if you have a drawing
Planning drawings
Design cost check
Detailed drawings
Design cost check, or a builder pricing pack if you're ready for builders to price
Builders' quotes in hand
Budget Reality Check on the quotes, or a builder pricing pack so they re-price the same list
Already on site
Book a free 15-minute call
Want a quantity surveyor to look at your budget?
Budget Reality Check: £195 including VAT
A quantity surveyor reviews your calculator answers and any drawings you have, then goes through your budget with you on a 30-minute online call. It suits any stage, from an early idea to comparing builders' quotes.
Your fee for a design cost check or builder pricing pack is held for 6 months. If you book either within 3 months, we credit the £195 against it.
Our guarantee: if you don't leave the call with a clearer view of your budget, tell us within 7 days and we'll refund the £195. It covers the service, not the cost figures, and applies when you have shared the information we asked for and attended the call. One claim per project.
✓ A quantity surveyor's review of your answers and any drawings, before the call
✓ A 30-minute online call
✓ A written action list after the call
✓ A guide pack for your project stage
✓ Questions by email for 14 days
We keep a limited number of Reality Check calls each week.
Pay securely, then choose a time. Terms.
Our fees
Fixed fees, including VAT, based on the construction cost of your project. Your own fee comes in the fee proposal with your budget report, and a quantity surveyor confirms it before you pay.
Budget Reality Check
£195
A 30-minute call with a quantity surveyor about your budget
A 30-minute online call with a quantity surveyor who has already looked at your answers and any drawings. You come away with a written action list and a clearer view of whether your budget fits what you want to build.
Design cost check (Elemental Cost Plan)
from £595
What your drawn design should cost, element by element, before you go to planning or builders
We measure your architect's drawings and price each part of the build, from foundations to finishes. It shows what your design should cost and where the money goes, while there's still time to change the design. Read more
Builder pricing pack (Schedule of Works)
from £1,495
One detailed list every builder prices, so their quotes compare like for like
A detailed list of all the work, measured from your drawings, that every builder prices. Because they all price the same list, you can compare quotes line by line and see what each one has left out. Read more
Design cost check and builder pricing pack together
from £1,895
Both, for less than booking them separately
A design cost check while the design develops, then a builder pricing pack when you're ready for builders to price. Booked together, they cost less. Read more
All prices include VAT. For projects over £500,000 we have a short call with you before you order, and over £1.5 million we send a proposal after a call.
It gives a planning range from your answers, using our rates per square metre adjusted for your region. It can't see your home, your design or your ground conditions, so the final cost may fall outside the range. A design cost check of your drawings is the next step for a firmer figure.
Yes. We ask for your first name and email so we can show your figure and send your budget report. We don't ask for a phone number.
Your budget report and fee proposal, then a few short emails with tips and podcast episodes for your project, timed to when you hope to start. Tick "Just send my report" if you only want the report. Every email has an unsubscribe link.
Yes, at 20%, which applies to most extensions and renovations. Building a new home is usually zero-rated when a VAT-registered builder does the work, so we don't add VAT for new homes. Some work may qualify for 5%; a VAT specialist needs to confirm this for your project.
Professional fees, surveys, planning and Building Control fees, party wall costs, kitchen units, worktops and appliances (unless you add your own budget), loose furniture, moving out, finance costs, and price rises after Q4 2026.
A design cost check (Elemental Cost Plan) prices your drawn design element by element, so you can see where the money goes while the design can still change. A builder pricing pack (Schedule of Works) is one detailed list of the work that every builder prices, so their quotes compare like for like. Read more
Yes. The calculator adjusts for every UK region, and we prepare design cost checks and builder pricing packs from your drawings by email and online calls.
A builder's quote is free because it's part of winning the job, and each builder prices the work as they understand it. A design cost check is independent: it tells you what your design should cost before you choose a builder, so you have something to check quotes against. Read more
Questions
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