In the world of construction contracts, clarity, coordination, and control are everything. Nowhere is this more true than under the JCT Design and Build Contract, one of the most widely used standard forms in the UK.
At the heart of every JCT D&B contract lie three essential documents,each one powerful on its own, but only truly effective when working in harmony. These are:
- The Contract Sum Analysis (CSA)
- The Employer’s Requirements (ERs)
- The Contractor’s Proposals (CPs)
Together, they form what I call the Holy Trinity of JCT documentation.
Let’s break them down. What they are, why they matter, and how to keep them aligned.
But before we do, At Metroun, we help you get the basics right – drafting, reviewing, and aligning JCT contract documents so your project starts on solid ground.
1. Employer’s Requirements (ERs): The Vision
The Employer’s Requirements lay out what the employer expects from the contractor. Think of this document as the client’s brief. It defines the scope, performance criteria, design intent, and project constraints.
Key elements of a strong ER include:
- Scope of works and performance outputs
- Site and logistical constraints
- Key programme dates
- Quality standards and regulations to be met
Good ERs provide clarity, consistency, and a benchmark against which tenders can be evaluated. Weak ERs, or worse, vague ones, leave room for misinterpretation and dispute.
And in Design and Build contracts, performance-based ERs are particularly important. They allow the contractor flexibility in design while holding them to measurable outcomes.
2. Contractor’s Proposals (CPs): The Offer
The Contractor’s Proposals are the contractor’s official response to the ERs. They show how the contractor intends to meet the employer’s requirements, from design approach to construction methodology, and everything in between.
CPs typically include:
- Drawings and design narrative
- Proposed programme and sequencing
- Method statements
- Assumptions, exclusions, and clarifications
The CPs form a contractual commitment, not just a set of ideas. If the contractor’s interpretation of the ERs differs, those differences should be clearly recorded and agreed before contract execution.
3. Contract Sum Analysis (CSA): The Financial Backbone
The CSA is the contractor’s detailed breakdown of the agreed contract sum. It transforms a single figure into a structured, line-by-line summary of costs across work elements or packages.
Its main purpose? To support valuations and payments. Every interim application, every cash flow forecast, every cost report relies on this document.
But it’s not just a commercial tool, it’s also a risk management document. A well-structured CSA:
- Provides transparency for project stakeholders
- Forms a basis for assessing variations
- Helps track actual vs. forecasted expenditure
However, the CSA is not a scope-defining document. If the contractor fails to price an item in the CSA but it’s required in the ERs or CPs, it still must be delivered. This is a common misconception—and a common source of disputes.
The Importance of Alignment
Each of these documents plays a different role:
- The ERs define “the what”
- The CPs define “the how”
- The CSA defines the “how much”
When they align, you get a clear, coordinated contract—one where expectations, delivery methods, and budgets are all on the same page.
But when they don’t? You open the door to:
- Misunderstood scope
- Disputes over quality or compliance
- Disagreements over payment entitlement
That’s why early coordination and careful cross-checking are essential—before contract signature.
Conclusion
The Holy Trinity of JCT contracts—CSA, ERs, and CPs—are more than just administrative requirements. They are the foundation on which your entire project rests.
Treat them with the attention they deserve.
Review them in parallel.
Keep them aligned.
Because when they work together, projects run smoother. When they don’t, someone ends up footing the bill.
