Hiring a Loft Conversion Builder: Questions to Ask

Why the Right Questions Save You Thousands

A loft conversion is one of the few home improvements that gives you extra living space without touching the garden. It also happens to be one of the most disruptive, technical and expensive projects a typical household will ever take on. The builders who quote for it will all sound confident, and their prices may be surprisingly close. What separates a smooth six-week job from a nine-month nightmare usually comes down to details that were never discussed before the contract was signed.

Once you have handed over a deposit and scaffolding is up, your bargaining position shrinks dramatically. So treat the quotation stage as your best opportunity to be nosy. A good builder will welcome the questions below; the ones who dodge them are telling you something useful.

Insurance: Ask for the Certificates, Not Just a Reassurance

Every contractor should hold employer's liability insurance, which is a legal requirement in the UK and should be at least £5 million. Beyond that, look for public liability cover of £2 million or more, protecting you if someone is injured on your property or a neighbour's wall is damaged, and contract works insurance, which protects the structure itself while it is being altered. Many household policies will not cover a home mid-conversion.

• Ask for current certificates, dated within the last twelve months.
• Check the policyholder's name matches the company you are actually paying.
• If subcontractors will be used, ask whether they are covered under the main contractor's policy or hold their own.

If a builder cannot produce paperwork quickly, treat that as a serious warning rather than a clerical oversight.

Their Track Record in Loft Conversions Specifically

Extensions and loft conversions are different disciplines. Loft work involves roof structures, headroom calculations, fire separation and staircases squeezed into tight spaces, and it is worth asking how much of it they do.

• How many lofts have you completed in the past two years?
• Can I speak to three recent clients with a similar house to mine?
• Have you worked on my type of roof, whether that is a Victorian hipped roof, a trussed-rafter new-build or a terraced property?

Where possible, visit a finished project. Look at the joinery around the staircase, the finish on the sloping ceilings and the headroom on the landing. Ask the homeowner whether the builder turned up when they said they would and whether snagging was dealt with promptly.

Building Control, Structural Calculations and Party Walls

This is where questions get technical and where the costliest misunderstandings begin. Establish early who is instructing the structural engineer and who is paying for those calculations, because they are usually a separate cost from the build itself.

You also need to know which route to building regulations compliance is being used: your local authority building control team or an approved inspector. Either is acceptable, but someone must be responsible for issuing the completion certificate you will need when you come to sell.

If your home is terraced or semi-detached, the Party Wall etc. Act 1996 probably applies. Ask who will serve the notices, who appoints the surveyor and who pays the fees, which are normally yours as the building owner. Flats and maisonettes bring additional fire requirements, including protected escape routes and fire doors, so ask how these will be handled.

Finally, ask whether the work falls under permitted development rights or needs a full planning application, and whether a Lawful Development Certificate is worth applying for as future-proofing.

Money: Payment Schedules, Deposits and Variations

Never pay a large sum before meaningful work has begun. A reasonable deposit is up to 10 per cent, with the balance released against completed stages rather than calendar dates.

• Are payments tied to milestones, such as scaffold erected, roof structure in place, plastered, second fix complete?
• Is a retention of 2.5 to 5 per cent held back for an agreed period after completion?
• How are variations priced and approved, ideally in writing before the extra work starts?
• What happens if the builder becomes insolvent mid-project?

Pay by bank transfer so there is a clear record, and keep every invoice.

Contracts, Timelines and Site Practicalities

Insist on a written contract, ideally a standard form such as a JCT minor works agreement, with a schedule, drawings and specification attached. It should cover the start date, working hours, expected duration and the process for resolving disputes.

• Who is your day-to-day point of contact, and who will be on site?
• Where will materials and skips be stored, and will scaffolding affect neighbours?
• How will dust be contained, and which ceilings or floors are being removed?
• What guarantee is offered, and is it insurance-backed for ten years?

Ask all of this before signing, get the answers in writing, and you will start the project with clear expectations on both sides. That single habit prevents more loft conversion problems than any other.