Learn to interpret your results
Build a renovation budget with contingency
Published on
A useful renovation budget lets you review quantities and scope before discussing the total. Divide work into measurable items and distinguish materials, labour and extras. Contingency is money available for uncertainty, not an already contracted invoice or a percentage guaranteed to cover every overrun.
Hypothetical example, in EUR
A hypothetical 50-unit item at EUR 20 material and EUR 30 labour costs EUR 2,500. A 10% reserve adds EUR 250. Applying a manual 20% tax afterwards adds EUR 550, giving EUR 3,300. At 50 m² this is EUR 66/m². Do not add that tax again if supplier prices already include it.
50 × (20 + 30) × 1.10 × 1.20 = 3 300 EUR
What to check before deciding
Ask suppliers to describe the same scope so alternatives are comparable. Check quantity, measurement unit, inclusions and tax treatment. This estimator’s single percentage does not reproduce different taxes per item. Vary contingency to see how much budget to retain, without treating an estimate as a contract or assuming current market prices.
What can change the result?
Quantities, scope, unit prices and reserve. Identify tax already included in each quotation before using one common rate.