Behind The BuildLens
The number is built, not guessed.
Every BuildLens figure is constructed from live UK cost data and the full measurement of your plans — never estimated from a rule of thumb.
On any project, the cost is the number that decides whether it is worth doing. It is also the one most people commit to without ever testing it.
The gap between the figure you expect and the figure you pay is consistent and well documented, and it is where projects come undone.
So we do the plain thing: we build the number from the ground up, and we show the working.
The method
How a BuildLens number is built
Live cost data
Merchant pricing tracked weekly across UK suppliers, set against current trade labour rates. The cost of materials and labour as they stand now — not a national average, and not last year's figure.
Your plans, measured in full
Every external and internal wall, the roof, and every window and door opening, for the existing house and the proposed work. Taken from your drawings — never floor area multiplied by a rate.
Built up trade by trade
The figure is assembled from the actual scope of work and itemised by trade — groundwork, structure, roofing, joinery, services, finishes. Not handed down as a single headline number.
Calibrated to your postcode
The same work costs materially more in some places than in others. Your figure reflects the real cost where the property is, not a blended national rate.
Held for review when it cannot be measured
If the drawings or the scope leave something that cannot be measured cleanly, the figure is not guessed. It pauses for a person. That discipline is what makes every other number in the report one you can act on.
The reading and the measuring are done by our system, in hours rather than weeks. The speed is the machine's contribution. The standard each number is held to is not.
What that gives you
A number you can plan against before you commit — itemised, calibrated to where you are, and built from current cost rather than guessed from a rule of thumb.
It is a desktop analysis, built from your drawings rather than a visit to the property, and the report is plain about that: where something needs eyes on site, it says so rather than claim a precision it cannot have. The aim is not to remove every unknown — it is to put the real cost in front of you while you can still do something about it.
Most projects come unstuck at the same place: where ambition meets cost, found out too late. A real number, built from real data, before you commit, is how you reach that point early instead.
The number is built, not guessed.
See the reports →