How to compare garage conversion quotes

Why is the cheapest quote not always the cheapest project?

Garage conversion quotes often look comparable because they use the same headline words: insulation, plastering, electrics and decoration. The detail underneath can be very different. One price may include the design, approvals, waste removal, flooring and final certificates; another may assume you will organise or pay for them separately. A low total is only meaningful when the scope is the same.

Your goal is not to find the longest document. It is to make the important assumptions visible so you can compare like with like and identify what could become a variation later.

What should every quote describe?

Start with the physical work. The quote should identify the garage type, approximate dimensions, intended room and any external changes. It should explain the floor build-up, damp treatment, wall and roof insulation, windows, doors, heating, electrics, ventilation, plastering, flooring and decoration. If there is a bathroom or utility area, drainage routes and sanitaryware should be described rather than hidden inside “plumbing allowance”.

• Included work: the tasks, materials and finish standard being priced.
• Excluded work: items you may need to arrange, such as specialist surveys, planning applications, landscaping or fitted furniture.
• Allowances: provisional amounts that may change when a product or condition is confirmed.
• Assumptions: statements about access, existing structure, drainage, parking and working hours.
• Completion evidence: who handles inspections, certificates, electrical testing and warranties.

How do you compare two different specifications?

Create a simple comparison table with one row for each major element. Put the contractor's price in one column and mark each item as included, excluded, provisional or unclear. Pay particular attention to the garage door opening, floor level, structural work, consumer unit, heating connection, ventilation, decoration and waste. These are common places for a “similar” quote to stop being similar.

Then compare the programme and payment terms. A fair quote should show a start assumption, estimated duration, payment stages and how changes are agreed. Be cautious about a large upfront payment with no clear materials, mobilisation or protection of your money. Ask what happens if the start date moves or an inspection identifies additional work.

What questions should you ask before accepting?

1. Who has inspected the garage, and what could not be confirmed before opening up?
2. Which planning and building-control route is assumed?
3. Who pays application fees and books inspections?
4. What does the price include for insulation, floor level, windows and ventilation?
5. How are variations priced and approved?
6. What insurance, warranty and complaint route applies to the work?
7. What documents will I receive at completion?

What does a good quote feel like?

A good quote makes you more confident because it explains the work, not because it uses impressive language. It should match your brief, acknowledge the unknowns and tell you who is responsible for each approval and decision. Compare the people and process as well as the number: relevant conversion experience, clear communication and a willingness to discuss exclusions are useful signals.

Check that the quote is for your garage rather than a generic template. The wording should reflect the actual floor level, garage door, access route and room use. If every contractor has made the same mistake, correct the brief before comparing the revised prices. It is also reasonable to ask for a contactable reference for a recently completed conversion, evidence of relevant insurance and the name of the person managing the work day to day.

Before signing, send the same questions to each contractor and give them a chance to correct misunderstandings. Keep the final specification, drawings, quote, exclusions, payment schedule and warranty together. That pack becomes the reference point if the scope changes.