How to calculate the cost of a small renovation
Build a usable small-renovation budget by separating materials, consumables, labour, waste, transport and contingency instead of relying on one total figure.
What you need to know
- Separate materials, consumables, labour, transport and waste.
- Compare quotes only when they cover the same scope.
- Keep contingency visible instead of using it to hide uncertain quantities.
Split the work into cost groups
Start with removal or demolition, preparation, main materials, consumables, specialist work, labour, transport, waste and final finishing. Separating these items makes it much easier to understand why a budget changes.
Use a simple subtotal and contingency
If materials are €600, consumables €120, labour €900 and waste removal €80, the subtotal is €1,700. A 10% contingency adds €170, giving a planning figure of €1,870 before any scope changes.
Compare like with like
Two quotes are not directly comparable if one includes protection, waste removal, finishing or taxes and the other does not. Create the same checklist for every contractor and mark included, excluded and optional items.
Track planned, committed and paid
Use three columns during the job. When a €300 item becomes €420, you immediately see how much contingency has been consumed and can decide where to adjust before overruns accumulate.
Final check
Before buying materials or carrying out the work, review the assumptions, product data and limits that apply to your real situation.
- Use the same scope for every quote.
- Keep preparation and waste as visible items.
- Ask for extras and changes in writing.
- Save invoices and product references.
Keep a short job record
Write down the measurements, product reference, technical values, date and final result. Photos of labels, settings and the starting condition make future checks and repairs much easier.
BricoDato tip: repeat any important measurement or diagnostic check before making an expensive decision.
Turn the guide into a decision
Use BricoDato calculators to quantify materials before pricing the work. If the work affects fixed electrical systems, structure, hidden leaks, vehicle safety or another safety-critical area, use a qualified professional when appropriate.