Compare loft conversion quotes, line by line

A loft conversion involves the room and the route to it. Stairs may reshape the landing below. Structural changes affect ceilings and walls elsewhere, and fire-safety measures can extend through the house. A detailed bedroom quote can still omit those connecting tasks.

Give each trader the same design and intended use. Roof windows, dormers, an en-suite and storage areas are not interchangeable versions of one identical project. Identify what has been surveyed and which headroom, structural and service-route assumptions still need professional confirmation.

Do not treat a quotation as proof the layout is feasible or approvals are secured. Ask for a complete path from the existing landing to the finished space, including making good on lower floors. The comparison should help you ask better questions, not replace design or regulatory advice.

What a complete loft conversion quote should include

• Design and use — Identify room use, drawing revisions, storage and any en-suite. Separate a habitable-room conversion from simple loft boarding.
• Survey assumptions — Record dimensions and inspections already completed, plus headroom, structural and layout questions still awaiting technical assessment.
• Structural changes — Describe floor strengthening, steels, roof alterations, temporary support and making good where work affects the floors below.
• Roof alterations — Specify dormers, roof windows, coverings, flashings and gutters, including the junctions between new and retained parts.
• Staircase — Include manufacture, fitting, guarding, handrails and the new opening, along with alterations to surrounding walls and doors.
• Usable space — Agree measurements and how sloping ceilings affect layout, access and furniture positions rather than relying only on floor footprint.
• Fire-safety measures — Identify the agreed design and work required on lower floors or the escape route, with the appropriate professional responsible.
• Insulation and ventilation — Set out construction and moisture-control arrangements. Confirm how the build-up relates to the approved design and retained roof.
• Electrics — Include sockets, lights, alarms, controls, testing and any changes to the existing installation needed for the conversion.
• Heating and plumbing — Describe connections, controls and assessments of existing systems, including routes and reinstatement outside the loft.
• Finishes — Define plaster, doors, joinery, flooring and decorating. If there is an en-suite, supply a separate fitting and finish schedule.
• Protection and handover — Include scaffolding, temporary weather protection, occupied-house protection, disposal, snagging, inspections and completion documents.

What's often left out — and what it can cost

The loft reference below is an area-based guide, not a separate price for each component. Ask what floor quantity is used and whether it includes restricted-headroom areas. Different measurement methods can make even similar rates misleading.

There are no standalone loft benchmark rows for a staircase, dormer, individual steel or lower-floor fire-safety changes. Make these explicit work items and request written prices where they are excluded. Do not split the broad range into invented allowances.

An en-suite mentioned in a loft proposal still needs a specification for drainage, fittings and waterproofing. A general window benchmark is not automatically suitable for a roof window either. Check exact product and job matches rather than importing unrelated categories into the calculation.

An illustrative loft conversion comparison

Quote B’s staircase wording needs clarification even though its en-suite is included. Quote C needs a precise fire-safety boundary. Ask about the lower floors as well as the new room before deciding which proposal delivers your agreed design.

Questions to ask each trader

• Which design and survey information supports the price, and which assumptions need confirmation?
• What work is included below the loft, including stairs, doors, landing and ceiling repairs?
• How are scaffolding and weather protection arranged while the roof is open?
• Is the final total inclusive of VAT, and how are extras treated?
• What deposit is required, what does it fund and which completed stages trigger payments?
• Who manages design changes, approvals, inspections and completion documents?

Your loft conversion questions

Compare the complete route through your existing home to the finished loft. Resolve headroom, stairs and lower-floor work before signing, so the proposal reflects the project rather than just the new bedroom.