# DESIGN AND BUILD CONSTRUCTION CONTRACT
## Important warning
This fictional contract is an illustrative worked example for an extension to a home in England and Wales. It is not a survey, planning permission, building-regulations approval, party-wall notice, structural design or legal advice. The parties must check title, planning, building control, the Party Wall etc. Act 1996, the Building Regulations 2010, the Construction (Design and Management) Regulations 2015, health and safety, asbestos, insurance, consumer rights, VAT, tax, payment law and any mortgage conditions. The contractor must not hide defects or treat a certificate as a waiver of statutory rights. Names, plans, dates and amounts are fictional.
Date: 2 February 2027
Employer: Olivia Hart and Daniel Hart of 24 Willow Rise, Warwick CV34 6QJ.
Contractor: Stonebridge Build Limited, company number 08427195, of 5 Foundry Lane, Coventry CV1 4GH.
## 1. Project and documents
The Contractor will design and construct a single-storey rear extension, utility-room alteration and drainage works at 24 Willow Rise (Works) in accordance with this Contract, drawing set SB-WR-01 to SB-WR-12 dated 20 January 2027, the Employer's requirements in Schedule 1 and the accepted quotation SB-274 dated 24 January 2027. If documents conflict, the order of precedence is this Contract, the Employer's written clarification, the drawings, the specification and the quotation. A change must be recorded as a written Variation.
The Contract Price is £186,000 including VAT at 20%. The net price before VAT is £155,000 and VAT is £31,000; £155,000 + £31,000 = £186,000. The price includes labour, materials, design, plant, waste, testing, ordinary protection, Contractor overhead and profit, and the provisional sums expressly stated in Schedule 2, subject to adjustment under this Contract. The Contractor confirms that it inspected the site on 12 January 2027 and allowed for ordinary access and ground conditions visible at that inspection.
## 2. Programme and possession
The Contractor will begin on 15 March 2027, achieve practical completion by 30 September 2027 and remove its plant by 7 October 2027. The programme includes 25 working days for design coordination and approvals. The Contractor must provide a two-week look-ahead every Friday, keep the site secure and protect occupied parts of the home. The Employers will provide access between 8.00 am and 5.30 pm Monday to Friday and 8.30 am to 1.00 pm Saturday, subject to reasonable notice.
The completion date is extended only for a proven delay caused by an Employer instruction, an authority delay not caused by the Contractor, exceptionally adverse weather recorded in the site diary, or an event beyond reasonable control. The Contractor must notify the likely delay within five working days, identify mitigation and give a revised programme. It must not claim an extension for its own shortage of labour, late procurement or poor coordination.
## 3. Design, approvals and compliance
The Contractor is responsible for its design and must appoint competent designers, provide calculations and coordinate structural steel, insulation, drainage, ventilation, electrical and fire-safety details. Before starting the relevant work it must obtain Employer approval of design information, but that approval does not transfer design responsibility. The Contractor must submit applications and notices to the appointed building-control body and comply with its requirements. The Employer remains responsible for planning permission and party-wall agreements unless Schedule 1 says otherwise; the Contractor must not start work requiring an approval that has not been obtained.
The Contractor is principal contractor and principal designer for CDM purposes to the extent applicable. It must prepare the construction phase plan, welfare arrangements, risk assessments, method statements, competence records and health-and-safety file. It must identify asbestos risk, stop work if suspect material is found and notify the Employer. It must comply with environmental, waste-transfer and working-hour requirements and must not burn or bury waste on site.
## 4. Quality and materials
The Works must be carried out with reasonable care and skill, in accordance with the Contract, manufacturer instructions and good construction practice. Materials must be new, fit for purpose, of the specified grade and accompanied by certificates where required. The Contractor must provide samples of facing brick, roof tile, windows, doors, kitchen fittings and floor finishes before ordering. Substitution requires prior written consent and must be no lower in performance or appearance.
The Employer may inspect and test work, but inspection does not relieve the Contractor of responsibility. The Contractor must promptly uncover and reinstate work reasonably suspected to be defective. If a defect is found, it must repair or replace it at its cost within a reasonable time. A concealed defect discovered after practical completion remains the Contractor's responsibility, subject to limitation law and the express defects period.
## 5. Price and payment
The Employers will pay the Contract Price in the following VAT-inclusive stages against a valid invoice and photographic progress record: deposit on signing £18,600; foundations and drainage complete £27,900; structural shell and roof weather-tight £46,500; first-fix services and windows complete £37,200; plastering, joinery and external works substantially complete £37,200; and practical completion and handover £18,600. These amounts total £186,000: 18,600 + 27,900 + 46,500 + 37,200 + 37,200 + 18,600 = £186,000.
The Employer must pay an undisputed invoice within 14 days. The Contractor must state the payment due date, basis and final date for payment and may not suspend work without the notice required by the Housing Grants, Construction and Regeneration Act 1996 where that Act applies. The Employer may withhold a genuinely disputed amount only by giving a timely notice stating the sum and grounds. No invoice is acceptance of defective work.
## 6. Variations and provisional sums
Only the Employers or their named contract administrator may instruct a Variation. The Contractor must price a proposed Variation within five working days, stating labour, materials, VAT and programme effect. It must not carry out additional work merely on an informal conversation unless emergency work is needed to protect people or property. A signed variation record is binding on scope and price, subject to discovering concealed conditions.
The Contract includes two provisional sums: £4,800 for upgraded kitchen appliances and £6,000 for unforeseen drainage diversion, both VAT-inclusive. If the actual cost of the appliance package is £5,400, the adjustment is £600. If the drainage diversion costs £4,500, the adjustment is a £1,500 credit. The adjusted Contract Price would therefore be £186,000 + £600 - £1,500 = £185,100, before any other signed Variation. The Contractor must provide invoices and must not add profit twice.
## 7. Site, insurance and responsibility
The Contractor is responsible for its employees, subcontractors, plant, materials and security until practical completion. It must maintain employers' liability insurance as required by law, public liability of at least £5,000,000, contract-works insurance for reinstatement value, and professional indemnity of at least £1,000,000 for design. It must provide certificates before starting and notify the Employers of cancellation or material change.
The Contractor must protect the existing house, keep access routes reasonably clean, control dust and noise, maintain temporary weatherproofing and repair damage it causes. The Employers remain responsible for their contents and must not instruct unsafe work. Neither party is liable for loss that cannot lawfully be excluded; subject to that, neither party is liable for indirect loss, but this does not exclude the reasonable cost of remedying defective Works or liability for fraud, death or personal injury caused by negligence.
## 8. Practical completion and defects
When the Works are complete, safe, weather-tight and capable of beneficial occupation, the Contractor may request inspection. The Employers will provide a snagging list within seven days. Practical completion is not achieved until agreed essential defects are corrected, rubbish is removed, test certificates and warranties are delivered, the building-control completion certificate or equivalent evidence is provided, and the health-and-safety file is handed over. Minor snagging that does not prevent use may be listed with a completion date.
The defects period is 12 months from practical completion. The Contractor must attend an urgent defect affecting safety or water ingress within 24 hours and other notified defects within five working days, then complete reasonable remedial work promptly. The Employers may obtain emergency protection if the Contractor does not respond and recover reasonable evidenced cost, after giving notice where practicable. A manufacturer warranty does not replace the Contractor's contractual responsibility.
## 9. Suspension and termination
Either party may terminate for a material unremedied breach after 14 days' notice. The Employers may terminate immediately for abandonment, insolvency, serious safety breach or deliberate concealment of a defect. The Contractor may suspend for non-payment only after the required statutory and contractual notices. On termination, the Contractor must secure the site, give the Employers design documents and certificates, assign transferable supply warranties, remove its plant and account for materials paid for.
The Employers will pay the value of properly performed work, less reasonable completion and defect costs, and the Contractor must refund any overpayment. Termination does not affect accrued rights, confidentiality, warranties or dispute provisions.
## 10. Records, notices and disputes
The Contractor must keep a daily site diary, labour and delivery records, waste notes, inspection requests, test results, photographs and invoices for six years. Notices must be in writing by hand or first-class post to the addresses above, or by email to an email address notified in writing for notices; a termination notice must be sent by both email and post. A dispute must first be discussed by the parties within five working days, then referred to a jointly appointed adjudicator where the statutory right exists, without preventing urgent court relief or a claim for defects.
## 11. Governing law
This Contract and any non-contractual dispute are governed by the law of England and Wales. The courts of England and Wales have exclusive jurisdiction, subject to any statutory adjudication or other mandatory process.
## Schedule 1 — Employer's requirements
The extension is approximately 6.2 metres by 4.1 metres, with insulated cavity walls, a warm flat roof, three aluminium doors, two rooflights, a utility sink, compliant electrics, mechanical extraction and connection to the existing drainage run. The Contractor must provide product certificates, electrical certification, gas and plumbing certificates where applicable, building-control records, warranties, as-built drawings and a maintenance guide. Working hours must respect neighbours and the Employers' occupation.
## Schedule 2 — payment and provisional-sum record
Base Contract Price including VAT: £186,000. Deposit £18,600, foundations £27,900, shell £46,500, first fix £37,200, finishes £37,200 and completion £18,600. Provisional sums: appliances £4,800 and drainage £6,000. Any adjustment must be evidenced by supplier invoice and written Variation. A numerical total in a progress certificate cannot waive a defect or change the agreed scope.
## Signatures
Signed for Stonebridge Build Limited: ____________________ Name: Daniel Price, Director Date: ____________________
Signed by Olivia Hart: ____________________ Date: ____________________
Signed by Daniel Hart: ____________________ Date: ____________________