Illustration generated for this guide. It does not represent a property for sale.
Separate your wishes from the building’s needs
A dated bathroom is immediately visible. A roof, electrical installation or ventilation problem is harder to assess. Prepare a list by category and distinguish comfort, safety and general condition. Do not draw technical conclusions from listing photographs alone.
Request quotations for comparable scopes
An undetailed quotation is hard to compare. Ask about preparation, materials, labour, waste removal and exclusions. Also ask what cannot be assessed without further investigation. Different amounts may simply cover different services. Keep assumptions alongside each figure.
Prepare your next step: That extension is useful. Are its documents equally clear?
Add the timetable to the budget
Can you live there during the work? Will you need to pay for another home? Do some tasks depend on permission or earlier work? These questions affect the real cost. Before buying, ask the relevant professionals what can be confirmed and what will remain uncertain until a more detailed assessment.
Describe your plans room by room
Rather than asking what a complete renovation costs, specify what you want to retain, repair and replace. For a bathroom, for example, state whether fittings stay in the same positions and what you expect for floors, walls and ventilation. Include access constraints, possible occupancy and intended timing. Contractors asked to price different scopes will produce figures that are difficult to compare. A clear brief helps you understand differences without automatically choosing the lowest quotation.
Compare the boundaries of quotations
For each proposal, note materials, labour, protection, waste removal, finishes and exclusions. Ask how discoveries during the work will be handled and how changes will be approved. Clarify timing and payment arrangements. An undetailed total leaves too much room for interpretation. Do not treat a contingency reserve as money already available for upgraded finishes: its first purpose is to cover what could not be defined initially.
Plan life around the building work
Renovation also carries an organisational cost. Consider access to the kitchen and bathroom, furniture storage and disturbance to neighbours. Check required procedures and permissions before scheduling work. If you must move out, add that expense. Plan tasks in a logical order with the professionals, particularly when several contractors are involved. Finally, retain accepted quotations, invoices, manuals and useful photographs in the property file. They will support maintenance and a future sale.
Sources and references
ComparImmo editorial team. Sources checked on 27 September 2026. Check the rules for the region and your circumstances before making a commitment.