Preparing your project: what to check at home and what to ask your contractor

Three quotes for the same kitchen renovation: €8,200, €11,500, €14,900. Which one to trust? The cheapest that « forgot » the electrical work? The most expensive that includes make-good no one asked for? Often, the problem isn't the contractor: it's the brief.

Without a clear floor plan and precise questions, everyone imagines a different job. On the other hand, arriving at the visit with dimensioned drawings, a list of constraints and the right questions changes quote quality… and confidence in your choice.

This guide gives you two concrete lists: what to check at home before the meeting, and what to ask your contractor to frame the project. Amounts below are indicative ballpark ranges, not quotes.

Why quotes diverge (and how to avoid it)

A contractor prices what they see and what you say. If areas, utilities or finish level stay vague, they fill the gaps: each in their own way. Result: three quotes, three scopes.

Real example on a 12 m² kitchen: one quote included rubble disposal (around €800) and floor make-good after demolition (€600), the other did not. Apparent gap: €1,700. Real gap once scope was aligned: under €300. Invisible at first glance.

The goal isn't to become a construction expert. It's to arrive with enough information for every proposal to describe the same project.

What to check at home before the visit

Walk through the room (or property) as if preparing a photo dossier + notes. Useful points:

• Areas and volumes: length × width of each room involved, ceiling height (ballpark if you don't have a laser measure). A 20 cm error on height can mean an extra roll of wallpaper or paint per wall.
• Openings: doors, windows, passages: approximate widths, swing direction.
• Visible utilities: outlets, switches, water supplies, drains, radiators, ventilation, gas. Moving a sink drain by 2 metres can cost €300-600: worth knowing before locking the layout.
• Current condition: cracks, damp, floors to redo, suspicious partitions (see our guide on opening the kitchen to the living room if you're removing a wall).
• Site access: floor level, elevator, parking, possible hours in a condominium. A 4th floor without an elevator often adds roughly 10-15% labour on heavy items.
• Documents: surveys, co-op plans, property description, « before » photos.

A well-framed photo set (full walls, corners, ceilings, meters) is often worth a long email.

You arrive…	Typical effect on the quote
Without dimensions or brief	Different scopes, hidden options, hard to compare
With plan + photos + questions	Same baseline, clearer gaps (finish, timeline, exclusions)
With indicative budget	More realistic discussion on finish level

What to ask your contractor (meeting checklist)

Ask these questions to every contractor, in the same order. You can then compare answers side by side. You can also download the PDF checklist to print.

1. Scope: what is included / excluded (demolition, rubble, plaster, paint, electrical, plumbing)?
2. Assumptions: which areas and conditions are you pricing on?
3. Contingencies: how do you handle discoveries (damp, utilities, load-bearing wall)? Written amendment or end-of-project adjustment?
4. Timeline: possible start date, indicative duration, dependency on other trades?
5. Insurance: liability / 10-year warranty: can you provide certificates? Check validity and that covered work matches the job (paint-only warranty won't cover a load-bearing opening).
6. Certifications: for some work (insulation, boiler…), is RGE certification relevant for grants?
7. Payment: deposit, schedule, price revision terms? A deposit over 30% before start should raise questions.
8. Deliverables: itemized quote, schedule, who coordinates if several trades?

Also ask whether they work from a shared plan: many prefer written dimensions over a vague sketch.

How Kodarch can help

Before the meeting, draw the room in 2D, note openings and try a layout variant if needed. The budget calculator gives an indicative budget range to frame the conversation: not a binding quote. Then send a share link to your contractor: same dimensions, fewer back-and-forths. To get started: Kodarch for homeowners.

Common mistakes to avoid

• Approving a lump sum without line-item detail: impossible to negotiate or compare later.
• Signing a quote without an end date or indicative delay penalties.
• Accepting mid-project changes with no written record (a text message is enough; verbal agreement isn't).
• Underestimating condominium timelines (general meeting approval, work hours, common-area protection).
• Choosing only on lowest price without checking insurance and exclusions.

Frequently asked questions

Do I need a professional plan before the first quote?

No. A simple dimensioned plan is often enough for a first estimate. The contractor will refine on site.

How many quotes should I request?

In practice, 2 to 3 quotes on the same basis (same plan, same questions) is a good ballpark to compare without burning out.

Does the calculator replace a quote?

No. It helps frame a budget. Only a company quote is an offer.

What if quotes still differ a lot?

Go back to scope: list included/excluded item by item, then send the same brief to each. In the kitchen example above, that's exactly what brought a €1,700 gap down to under €300. For the full method, see our guide Comparing 3 quotes line by line with a printable comparison table.

In summary

Preparing your project well is less about « knowing building codes » than making the project readable: what you check at home, what you ask your contractor, and a shared plan so everyone prices the same thing. For dimensions: Measure your room (8 )dimensions. On the contractor side, our mirror guide on handling clients without a brief covers how to qualify and lock scope before pricing.