Renovation mistakes: what to check before signing
Published on 31 July 2026 · Verified on 18 September 2026 · The Mestravaux.lu team
A detailed quote can still leave an important risk unanswered. Before committing, establish what the contractor has examined and what remains an assumption. These checks identify questions and documents to request; they do not establish a repair price for your property.
The essentials in 30 seconds
- Opening a wall calls for an assessment suited to the building.
- Suspect materials need assessment before they are disturbed.
- Discuss exclusions and additional work before signing.
Opening a wall on an assumption
Do not treat wall thickness or the sound of a tap as sufficient evidence of its structural role. Ask who assesses the structure, which plans or findings they use and which document defines the intervention. Clarify further investigations, protection measures and finishing work included. A remote estimate does not replace this check.
Treating suspect material as ordinary rubble
The ITM dates Luxembourg’s general asbestos ban to 2001, while some previously installed products could remain. A date alone therefore does not establish that asbestos is absent. Before drilling or removing suspect material, have a competent specialist determine the procedure; do not take a sample yourself to check.
Choosing insulation without investigating damp
The housing ministry recommends assessing the existing building and highlights ventilation after work on its envelope. Ask how signs of damp will be investigated and how air renewal will be provided. Do not choose insulation solely because a wall is described as « breathing »: request an explanation suited to the actual substrate.
Your project deserves an accurate estimate — it's free.
Request a quoteOrdering a kitchen before checking connections
Give the electrician and plumber your appliance list and technical sheets. Have existing connections, planned relocations and areas that cabinets will conceal identified. Request a price for adaptations before fixing the layout, without assuming that the distribution board or pipes necessarily need replacement.
Accepting an unclear extra
Request a written description of additional work, its price, schedule implications and alternatives. For an inaccessible area, record the initial assumption and when it will be checked. This does not remove uncertainty, but helps you understand the change before deciding.
Frequently asked questions
Can every repair be priced beforehand?
Not from a generic example. Separate defined work, options and items requiring investigation. Then compare proposals covering the same scope.
Is a newer house necessarily asbestos-free?
Do not draw that conclusion from a year alone. Give the person assessing the risk the known building history and details of the materials involved.
Is renovating in stages a mistake?
No. Ask which interventions need coordination and what must be protected or reworked in the next phase. No universal percentage surcharge is established here.
Take action
Your project deserves an accurate estimate — it's free.
Request a quote