How to compare renovation quotes before choosing a contractor

A worked example: what happens when the missing work is priced

These figures are hypothetical, not market rates or a project completed by Casa en claro. Both contractors price the same layout, cabinet models and worktop. Contractor A initially includes only supply and fitting; contractor B also itemises the other work. All figures in the table exclude IVA, Spain's value added tax, or VAT.

Contractor A confirms four additional costs in writing: €900 for dismantling, €1,800 for electrical work, €2,100 for preparation and finishes, and €500 for waste removal. They add up to €5,300. A's comparable total is now €17,300, while B remains at €17,000. The apparent €5,000 saving has disappeared.

This does not establish that A was dishonest or that B will produce better work. The first comparison simply covered different amounts of work. Had A priced those additional items lower, it might still have offered the better value. A missing line needs clarification; it is not evidence of fraud.

Give every contractor the same work list

A full renovation can mean different things to different companies. Establish whether the plumbing stays, the electrical panel is replaced and dismantled furniture is removed from the property. Each of those choices affects the cost, even if every offer uses the same general project description.

Provide a measured plan, a list of what you want to keep, the finishes you want and the work required. Ask the contractors to mark items as included, excluded or awaiting a check. A blank entry needs a response before you can treat the price as complete.

• For a bathroom, specify removal, preparation, any required waterproofing, connections, sanitary fittings and finishing work.
• For a kitchen, specify cabinets and fittings, worktop cut-outs, appliance models, connections, installation and disposal.
• Elsewhere in the home, record actual surface areas, preparation, doors, skirting boards, protection and final cleaning.

Check the quantities as well as the unit prices

Painting 20 m² at €12/m² costs €240. Painting 30 m² at €10/m² costs €300. The second price per square metre is lower, but its total is higher because it covers more area. Check which walls and ceilings each contractor has measured before using the rate to judge the offer.

For each item, ask for the quantity, unit, unit price and subtotal. Materials should have a stated model or a specification you can verify: ‘taps included’ tells you very little about what will be fitted. For paint, confirm preparation and finish; for flooring, check levelling and skirting boards. Use matching measurements, and keep floor and wall areas separate.

Compare the total including tax and separate expenses

Show the amount before tax, the tax charged and the total payable for both proposals. In the kitchen example, if 21% VAT applied to each, A would total €20,933 and B €20,570. That rate is an assumption for the calculation, not a statement that every renovation in Spain is taxed at 21%.

Check the applicable rate using the guidance from AEAT, Spain's tax agency, and ask the contractor to state which rate is used and why. List expenses outside the contract too, such as municipal procedures, technical professionals, a permit for a skip or temporary accommodation. Their necessity and cost depend on the project and municipality; a single standard percentage will not establish the total.

AEAT guidance on VAT for work on homes

Agree how extra work and payments will be handled

A damaged pipe discovered after opening a wall, an omitted socket and your later choice of a more expensive worktop are different reasons for a price change. Ask the contractor to distinguish an unforeseen condition, a quotation omission and a change you request. Each needs an explanation, an amount and any effect on the completion date.

Before work starts, agree in writing who can authorise changes and how approval is recorded. Link payments to stages you can check. The contract should identify the business and its NIF, Spanish tax identification number, along with the work, materials, exclusions, dates, warranty terms and process for reporting defects. Establish the purpose of any deposit and obtain a receipt. A promised discount is not a good reason to pay the entire price before the work.

• Before approval, request the description, reason, price and timing of any proposed extra.
• Record agreement in writing before that change is carried out.
• At handover, inspect the work and make a written list of anything still to be finished or corrected.

Send both companies these five questions

These questions turn an uncertain price comparison into a discussion about specific work and costs. Send the same questions to both contractors before negotiating or choosing an offer.

• Which jobs on my list are outside the price, and what would it cost to include them?
• What quantities and specified products have you allowed for?
• What is the total with tax, and which costs will I pay separately?
• What can be checked now, and what can only be established after opening up?
• How will we agree changes, payment stages and the completion date?

If important items remain undecided, treat the total as provisional. Ask for further detail, narrow the scope or compare another proposal. Make sure the level of certainty in your budget matches what the contractor has actually agreed.