Stage 4: Procurement & Contracts

Choosing your build route

The single biggest decision in procurement is how you will deliver the build. There are three main routes, each with a different balance of cost, risk, and management burden. Read our Build Routes guide for a full comparison, but in brief:

• Main contractor: You appoint one company responsible for the entire build. They manage all trades and materials. Higher cost (typically 15-20% markup over direct labour) but lower risk and much less of your time. Best for those with full-time jobs or limited construction experience.
• Self-build package company: A company supplies the structural system (typically timber frame) and manages its erection. You manage all subsequent trades. Good middle ground - structural risk is controlled, and the programme is more predictable.
• Direct labour: You manage all trades yourself, buying materials directly and coordinating the programme. Can save 20-30% on cost, but requires significant management time, good organisational skills, and the ability to resolve problems on site. Not recommended for first-time self-builders unless you have construction industry experience.

Getting competitive quotes

Get a minimum of three quotes for the main contract or package. This sounds obvious but many self-builders accept the first quote they receive, particularly if they have a good relationship with the contractor. A competitive process almost always saves money and usually surfaces important questions about the specification.

To get comparable quotes, all tenderers must price from the same document - ideally a bill of quantities prepared by a quantity surveyor, or at minimum a detailed schedule of works and specification prepared by your architect. Quotes based on verbal descriptions or rough drawings are not comparable and lead to disputes later.

Checking contractors

Before appointing any contractor, check:

• Insurance: Public liability (minimum £2m), employer's liability (legally required if they employ people), and ideally contract works (all-risks) insurance. Ask for certificates, not just a verbal assurance.
• References: Ask for at least two references from similar projects completed in the last two years. Call them, and ask if you can visit a completed project.
• Financial stability: A basic Companies House check will tell you if the company has any county court judgements or is in financial difficulty. A contractor going into administration mid-project is one of the most disruptive things that can happen on a self-build.
• Experience: Self-build is different from commercial work. Ask specifically how many self-builds the contractor has completed and whether they are familiar with your proposed structural system.

The build contract

Never rely on a verbal agreement or a simple quote letter as your contract. A proper build contract defines: the scope of works, the contract sum, the programme, the payment schedule, how variations are handled, what happens in the event of delay, and how disputes are resolved.

The JCT Homeowner Contract is the standard form for self-build and home improvement projects in England, Wales, and Northern Ireland. It is simple, widely understood, and protects both parties. It costs around £30 from the JCT directly. Scottish self-builders should use the SBCC Minor Works Contract.

Make sure the contract clearly states:

• A detailed description of the works (reference to drawings and specification)
• The contract sum and what is included and excluded
• The programme - start date, key milestones, and completion date
• A payment schedule tied to stage completion
• The process for agreeing variations (changes to the scope of works)
• Liquidated damages for delay (a fixed daily or weekly sum the contractor pays if they overrun)
• A retention mechanism (typically 5% held back until defects are resolved)

CIL self-build exemption

Community Infrastructure Levy (CIL) is a charge local authorities can impose on new development to fund local infrastructure. For a new house, it can amount to tens of thousands of pounds. Self-builders are exempt from CIL, but only if they apply for the exemption before starting work.

This is critical: if you break ground before registering for CIL exemption, you lose the exemption permanently. The application is straightforward and free - there is no excuse for missing it. Read our full CIL Exemption guide.

Note: CIL does not apply in Scotland. Section 75 planning obligations may apply instead.

Party Wall Act

If your build involves a new wall on or near a boundary, excavation near a neighbouring building, or work to an existing shared wall, the Party Wall etc. Act 1996 may apply. You must serve formal notice on affected neighbours at least two months before work starts.

If neighbours agree in writing, no surveyor is needed. If they dissent or do not respond, a party wall award must be agreed between surveyors before work can proceed. This takes time and costs money - do not leave it until the last minute. Read our Party Wall Act guide for the full process.

Finalising your mortgage

Submit your full self-build mortgage application once you have planning permission, Building Regulations approval, and a signed build contract. Lenders require all three. Allow four to six weeks for a formal mortgage offer.

Do not start work before the formal mortgage offer is in place. Lenders will not release stage funds on work already started without an offer.

Building Control notification

You must notify Building Control at least two days before starting work. If you are using the Full Plans route, your plans will already have been approved and you simply notify of commencement. If your lender requires stage inspections to be coordinated with Building Control sign-offs, agree this process with your inspector before work starts - it will make your stage drawdowns much smoother.