Lethal Subcontract Traps Caught in a JCT Design & Build Schedule of Amendments

Signing a bespoke Schedule of Amendments without line-by-line verification can expose your business to severe commercial and financial liabilities. Below is an analysis of four high-risk amendments recently audited through my automated contract diagnostic tool, highlighting why they were flagged and the exact redlines required to protect your cash flow.

1. The 3-Day Delay Notice Condition Precedent (Clause 2.26 & 4.21)

• The Clause: The main contractor amended Clause 2.26.1 to require formal written notice within 3 business days of a delay event, backed by full critical path programme substantiation, as an absolute condition precedent to claiming time or loss and expense.
• The Plain-English Risk: If site access is blocked and you fail to submit a detailed critical path delay notice within 72 hours, your right to an Extension of Time (EOT) and direct cost recovery is legally extinguished.
• The Commercial Exposure: Your business absorbs the financial burden of plant hire, standing labour, and prolongation costs, while remaining fully exposed to delay deductions.
• The Redline Fix: Strike out the condition precedent wording and negotiate a realistic 10-to-14-business-day notification window from when you become reasonably aware of the delay event.

2. Uncapped Liquidated and Ascertained Damages (Clause 2.29)

• The Clause: An amendment requiring the trade subcontractor to pay £15,000 per week for project delays, with the express stipulation that liability remains completely uncapped.
• The Plain-English Risk: You are held liable for main-contract project delay damages at a rate that bears no proportion to your individual trade package value.
• The Commercial Exposure: Delay penalties can rapidly surpass your total subcontract sum, creating severe balance sheet distress.
• The Redline Fix: Revert to standard JCT direct loss provisions, or enforce an express financial cap on delay liabilities (e.g., capped at 10% of the Subcontract Sum).

3. Upstream Contingent Retention Release (Clause 4.18)

• The Clause: Retention release dates were modified so that the first 2.5% moiety is held until Practical Completion of the entire Main Contract, and the final 2.5% is held until all main contract defects and final accounts are settled.
• The Plain-English Risk: Your cash retention is tied to the performance and paperwork of other trade packages on site.
• The Commercial Exposure: Your hard-earned 5% cash retention can remain locked away for years after your own trade package is fully completed and handed over.
• The Redline Fix: Ensure retention release dates are strictly anchored to the Practical Completion and defects liability period of your Subcontract Works, not the upstream main contract.

4. Fitness for Purpose Design Guarantees (Clause 2.19)

• The Clause: The standard obligation of “reasonable skill and care” in Contractor’s Designed Portion (CDP) works was deleted and replaced with an absolute warranty that the works will be “fit for intended purpose”.
• The Plain-English Risk: You are legally guaranteeing the outcome and performance of the completed design, rather than agreeing to design with standard professional diligence.
• The Commercial Exposure: Standard UK Professional Indemnity (PI) insurance policies exclude fitness for purpose warranties, leaving your business personally liable for structural rectification costs.
• The Redline Fix: Re-insert standard JCT wording limiting design liability strictly to the exercise of reasonable skill and care expected of an experienced professional consultant.