Construction estimates with Claude: document prices and isolate unknowns
Method and example: Construction estimates with Claude: document prices and isolate unknowns. Sources, assumptions and checks before sharing.
By Educasium
Estimate construction costs with Claude →
A construction estimate combines quantities, unit prices and scope. Claude can organize these in Excel, but it cannot turn an old reference into a current market price. Readers should be able to trace each amount.
Separate quantities from price assumptions
Attach a dated takeoff and specify included trades, location and finish level. For each price, provide its unit, date, source and scope: supply only or supply and installation, for example. Check included costs before adding uplifts.
The pack specifies detail and a trade summary, with low, middle and high scenarios. Its references are not a live pricing database connection. Replace values with project-appropriate data or explicitly label them as assumptions.
Recalculate a row manually
Fictional example: 20 m² at €30 excluding VAT per m² gives €600. At €40 per m², the same item costs €800. That range illustrates price variation, not a statistical confidence interval. An unknown quantity must not appear as a confirmed zero cost.
Check units as well: a rate per linear metre cannot be applied directly to an area. Review trade subtotals, exclusions and separately identified allowances before accepting the total.
Handle VAT and uncertainty separately
In France, the rate depends on conditions concerning the work and dwelling; an RGE label alone does not determine it. Confirm the project's applicable rate rather than repeating a template simplification. See VAT rates for building work, impots.gouv.fr.
If the rate is missing, present the amount excluding VAT and flag the unresolved input. Keep sources and a valuation date. To strengthen the quantity basis, use the takeoff from drawings guide.