WALEED TARIQNEC4 ECC Practitioner Course · Module 1: How the ECC fits together
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NEC4 ECC Practitioner Course · Module 1 of 14

How the ECC fits together

Leila Moss, commercial manager at Merrow Vale Civils, opens the Aldermere contract on its , 5 January 2026. Four deadlines fall due within five weeks. Where does each rule sit, and who acts on it?

19 stepsAbout 20 minutes

Independent course material. It is not published or endorsed by NEC. Short quotes from NEC4 (© NEC 2017) and the FIDIC Red Book (© FIDIC 2017) are used for review and comment. Read the full clauses in your own copy of the contract.

Exhibit 1The first five weeks

Four deadlines counted from two dates

First 1 week from the starting date
Mon 19 Jan
First early warning meeting2 weeks from the starting date
Mon 26 Jan
First programme4 weeks from the Contract Date
Mon 2 Feb
First assessment date4 weeks from the starting date
Mon 9 Feb
Three of the four clocks run from the , not the Contract Date.

Source: ECC 15.2, 31.1, 50.1. Aldermere Contract Data.

Key terms

Eight terms you will use on every ECC

Terms in this module

Tap a term with a dotted underline anywhere in the lesson to see its meaning.

Contract Date

The day the contract was made. Several tests look back to it, such as what an experienced contractor could have foreseen about physical conditions.

ECC 11.2(4)

starting date

The date in the Contract Data from which many first steps are counted, such as the first Early Warning Register and the first assessment date.

ECC Contract Data part one

Contract Data

The project details that complete an ECC. Part one holds the Client's entries and part two the Contractor's. Terms in italics take their values from it.

ECC Contract Data

Scope

Information that describes the works or limits how the Contractor may do them. It sits in documents the Contract Data lists or in an instruction. NEC3 called it Works Information.

ECC 11.2(16)

Parties

The two sides bound by the ECC: the Client and the Contractor. Roles such as the Project Manager are not Parties.

ECC 11.2(13)

Provide the Works

The Contractor's core duty: to do all the work needed to finish the works as the contract requires, plus the incidental work and services the contract calls for.

ECC 11.2(15)

identified and defined terms

Identified terms are printed in italics and get their values from the Contract Data. Defined terms have capital initials and meanings set in the conditions, mostly in clause 11.2.

ECC 11.1

Key Date

A date by which part of the work must meet a stated Condition, set in the Contract Data. Missing it can make the Contractor pay the Client's extra costs.

ECC 11.2(11)

Source: ECC 11.1, 11.2(4), 11.2(11), 11.2(13), 11.2(15), 11.2(16). Contract Data part one.

The documents

The Contract Data says which clauses and documents form the contract

Exhibit 2Aldermere's contract
Aldermere Water, the Client
Merrow Vale, the ContractorContract Data part two
  • 11%
Conditions of contract
  1. Core clauses, sections 1 to 9
  4. delay damages
  5. retention

No , so no extra conditions

What to build, and any limits on how. It is “in the documents which the Contract Data states it is in” (11.2(16)) or in an instruction.

The Client's description of the : three borehole logs. Used to judge physical conditions (60.2).

No ranking between them. Notify a clash (17.1).

  1. 1GeneralClauses 10 to 19
  2. 2The Contractor’s main responsibilitiesClauses 20 to 29
  3. 3TimeClauses 30 to 36
  4. 4Quality managementClauses 40 to 46
  5. 5PaymentClauses 50 to 53
  6. 6Compensation eventsClauses 60 to 66
  7. 7TitleClauses 70 to 74
  8. 8Liabilities and insuranceClauses 80 to 86
  9. 9TerminationClauses 90 to 93

The first digit of a clause number gives its section, so clause 17.1 sits in section 1. This module works mostly in the two shaded sections.

Source: ECC 11.2(16), 11.2(17), 11.2(18), 17.1, 60.2. Contract Data parts one and two. Core clause sections 1 to 9.

The documents

Notify a clash in the documents at once

Exhibit 3Model notice
What to writeNotice of an ambiguity or inconsistency

To: Dana Whitfield, Project Manager

We notify an (clause 17.1).

Drawing [number] shows [what].

Specification [clause] requires [what].

We found it on [date]. Please state how to resolve it.

In the Toolkit: Letter 07, ECC Notice Letters

Send it separately through the portal (13.7).

Download

Source: ECC 13.7, 17.1, 17.2, 60.1(1), 63.10.

The Options

Every ECC picks one main Option and one dispute resolution Option

Exhibit 4Aldermere's two choices
Contractor carries the cost riskClient carries most of it

Priced

A

Activity schedule

B

Bill of quantities

A pays per completed activity. B pays bill rates for quantities done.

Target

C

Activity scheduleAldermere

D

Bill of quantities

Paid plus . Any saving or overrun against the is shared.

Cost reimbursable

E

No target to share

Paid Defined Cost plus the Fee.

F

Management contract. The Contractor subcontracts most of the work. X16 is not used with it.

Option clauses fit into the core numbering. Module 10 covers Option C.

AdjudicationDispute Avoidance Board
The 1996 Act appliesThe Act is a United Kingdom lawW2No OptionW3 is not used here
The Act does not applySuch as AldermereW1AldermereW3

W1 and W2 use an , and W3 a . The 1996 Act is the Housing Grants, Construction and Regeneration Act. Aldermere is outside the United Kingdom and Aldermere Water chose adjudication, so W1. Module 13 covers all three.

Source: ECC Options A to F, with Option A 11.2(29) and Option B 11.2(30). X16. Options W1, W2 and W3.

Quick check · Documents and Options

Three questions on what you have just covered

Quick checkPick an answer to see if you are right and why
1Option C clause 20.4 (forecasts of Defined Cost) and core clause 20.1 both apply at Aldermere. Does 20.4 replace 20.1?
Only where the two clauses conflict with each other
Yes. An Option clause overrides the core clause it sits beside
No. Clause 20.4 is read with clause 20.1 and adds to it
2Merrow Vale's Wendlemoor Brook scheme in England has a Contract Date of 8 June 2026. The 1996 Act applies there. Which dispute resolution Option fits it?
W2, the adjudication Option for the Act
W1, the same Option as the Aldermere contract
W3, if the Client would prefer a board
3Dana resolves an inconsistency in Aldermere Water's Scope by instructing the dearer reading. How is the compensation event priced?
On whichever of the two readings is the cheaper for Aldermere Water
As if the Prices were for the reading that favours Merrow Vale
As if the Prices were already for the reading Dana chose

3 questions to answer

Source: ECC 17.1, 20.1, 63.10. ECC Option C 20.4. ECC Options W1, W2 and W3.

The people

Dana and Tom act for Aldermere Water, but neither is a Party

Exhibit 5Who is who
Client · a Aldermere Water
The contract
Contractor · a PartyMerrow Vale Civils Ltd

(20.1)

Project Manager · not a PartyDana Whitfield
instructs and certifies payment
Supervisor · not a PartyTom Barrow
watches tests and notifies Defects
Instructions

Such as changing the Scope or a Key Date (14.3).

Replies

She replies within the , and gives reasons if she does not accept (13.3, 13.4).

Payment

Assesses what is due at each , then certifies within a week (50.1, 51.1).

Tests

May watch any Merrow Vale test (41.3).

Defects

Until the , notifies and may order a search (43.1, 43.2).

The

Tom issues it at the defects date if no notified Defect is left. Otherwise, when all are corrected or the last ends, whichever is first (44.3).

Source: ECC 11.2(13), 13.3, 13.4, 14.3, 20.1, 41.3, 43.1, 43.2, 44.3, 50.1, 51.1.

The people

What a firm does decides whether it is a Subcontractor

Exhibit 6Subcontractor or not?
Firm 1 of 6

…

Whoever does the work, Merrow Vale stays “responsible for Providing the Works as if it had not subcontracted” (26.1). Dana accepts each Subcontractor before it is appointed (26.2).

Source: ECC 11.2(12), 11.2(19), 26.1, 26.2.

The people

Clause 10 binds the Project Manager and the Supervisor too

Exhibit 7Clause 10 in two sentences

Bound by clause 10

  • Aldermere WaterClient
  • Merrow ValeContractor
  • Dana WhitfieldProject Manager
  • Tom BarrowSupervisor
10.1Act as the contract states

So its time limits, such as the , bind Dana and Tom too.

10.2Mutual trust and co-operation

All four “act in a spirit of mutual trust and co-operation” (10.2). It shows in shared tasks such as (Module 4).

Down the supply chain

Cobalt's

Its clause 10.2 has the same duty. Unamended, so not submitted for acceptance (26.3).

Other subcontracts

Dana may refuse their documents if the duty is missing (26.3).

Source: ECC 10.1, 10.2, 13.3, 26.3. ECS 10.2.

Quick check · The people

Two questions on what you have just covered

Quick checkPick an answer to see if you are right and why
1Aldermere's first assessment date is 9 February 2026. Who certifies the payment, and by when?
Tom Barrow, by 16 February 2026
Dana Whitfield, by 2 March 2026
Dana Whitfield, by 16 February 2026
Aldermere Water, on 9 February 2026
2Suppose a pump that Cobalt Pumps installs does not meet the Scope. Who answers to Aldermere Water for it?
Merrow Vale, as if it had done the work itself
Cobalt Pumps, because it did the work
Dana Whitfield, because she accepted Cobalt's appointment

2 questions to answer

Source: ECC 14.1, 26.1, 50.1, 51.1, 51.2.

Clauses 11 to 14

Italics point to the Contract Data, and capitals point to a definition

Exhibit 8One date, two meanings
completion dateIn italics
Look inContract Data part one
At Aldermere30 April 2027The date as written
Completion DateCapital initials
Look inIts definition in clause 11.2(3)
At Aldermere30 April 2027Until it changes. From 5 May 2026, after compensation event CE007, it is 7 May 2027.

In the printed conditions, “terms identified in the Contract Data are in italics” (11.1). Capital initials mark a term the conditions define, mostly in clause 11.2.

How do key date and Key Date differ?

The key date is the date written in the Contract Data. The is that date until it is changed under the contract. At Aldermere, Key Date 1 is 30 September 2026.

Clause 11.2(11)

When is Completion?

When Merrow Vale has done all the work the Scope says is due by the . It must also have corrected any notified that would stop the Client using the works, or stop doing their work. If the Scope is silent, it is when Merrow Vale has done all the work needed for both.

Clause 11.2(2)

Source: ECC 11.1, 11.2(2), 11.2(3), 11.2(11), 66.2.

Clauses 11 to 14

A change the conditions do not provide for needs a signed agreement

Exhibit 9Sort the five changes
Change 1 of 5

…

Clause 12 also makes singular words cover the plural, and plural words the singular (12.1). The law named in the Contract Data governs the contract (12.2).

Source: ECC 12.1, 12.2, 12.3, 12.4, 14.3, 60.1(1), 60.1(4), 66.2.

Clauses 11 to 14

Acceptance by Dana or Tom moves no risk to Aldermere Water

Exhibit 10At Aldermere
Merrow ValeDana or TomMerrow Vale keeps
Merrow ValeProposes Cobalt as a Subcontractor
23 January 2026Dana accepts Cobalt
Merrow Vale keepsResponsibility for Cobalt's work
Merrow ValeSubmits its wet well design
31 March 2026Dana accepts the design
Merrow Vale keepsLiability for the design
Merrow ValeRepeats the culvert joint test
5 June 2026Tom watches it pass
Merrow Vale keepsResponsibility for any found later

What acceptance never changes

“the Contractor’s responsibility to Provide the Works or liability for its design” (14.1)

Source: ECC 14.1, 21.2, 26.2, 41.3, 43.2.

Clauses 11 to 14

Merrow Vale obeys only Dana, Tom or a notified delegate

Exhibit 11Is it an instruction?

“The Contractor obeys an instruction which is in accordance with the contract” (27.3)

  1. 1

    Is it from Dana, Tom or a notified ?

    Clauses 14.2, 27.3
    If no:
    Not an instructionCheck with Dana first
    If yes, go on to question 2.
  2. 2

    Does the contract allow this instruction?

    Clause 27.3
    If no:
    Not an instruction to obeySuch as Tom changing the Scope. Only Dana may (14.3).
    If yes, go on to the outcome.
  3. Obey itA Scope change is usually a compensation event

Dana or Tom may cancel a delegation, and may still take a delegated action (14.2). Aldermere Water may replace either after notifying Merrow Vale of the new name (14.4).

Source: ECC 12.3, 14.2, 14.3, 14.4, 27.3, 60.1(1).

Quick check · Clauses 11 to 14

Two questions on what you have just covered

Quick checkPick an answer to see if you are right and why
1Suppose Merrow Vale finishes all the work the Scope requires by the Completion Date. A notified Defect in the pump controls would stop Aldermere Water using the works. Is that Completion?
Yes. Only the work that the Scope lists is counted
No. That notified Defect must be corrected first
Yes, once Tom has certified that Completion is reached
2An Aldermere Water site engineer tells Merrow Vale to change the pipe route. Dana has notified no delegation. What should Merrow Vale do?
Follow it, because it came from the Client's own staff
Treat it as an instruction from the Project Manager
Ask Dana, and wait for her or a notified delegate

2 questions to answer

Source: ECC 11.2(2), 14.2, 27.3, 30.2.

On the project

On the Contract Date Leila diarises four deadlines

Exhibit 12Work out the first deadlines
Mon 5 Jan 2026
Mon 12 Jan 2026
First Dana issues it within a week of the starting date (15.2)
Mon 19 Jan
First early warning meetingDana calls it, within two weeks of the starting date (15.2)
Mon 26 Jan
First programmeMerrow Vale submits it within four weeks of the Contract Date (31.1)
Mon 2 Feb
First assessment dateDana sets it, at most four weeks after the starting date (50.1)
Mon 9 Feb

At Aldermere the and the starting date are both 12 January 2026. Change either date to see which deadlines move.

Source: ECC 15.2, 31.1, 50.1. Aldermere Contract Data.

Watch out

Six mistakes to avoid

Exhibit 13Common mistakes
Scope
Pricing from a document the Contract Data does not list

Only listed documents and instructions hold Scope.

ECC 11.2(16)
Clashes
Assuming the specification outranks the drawings

Nothing ranks them. Notify the clash.

ECC 17.1
Dates
Working to the tender completion date

Use the Completion Date as it stands.

ECC 11.2(3)
Instructions
Obeying someone Dana has not notified as a delegate

Check they are a notified delegate.

ECC 14.2, 27.3
Changes
Agreeing a change in a meeting or an email

It needs both Parties' signatures.

ECC 12.3
Design
Treating design acceptance as a transfer of risk

The design liability stays with Merrow Vale.

ECC 14.1

Source: ECC 11.2(3), 11.2(16), 12.3, 14.1, 14.2, 17.1, 27.3.

Summary

Every rule in this module, and where the contract keeps it

Exhibit 14The rules at a glance
TopicWhat the contract says
The documentsPart one names the conditions and lists the documents holding the Scope and Site Information.Clauses 11.2(16), 11.2(18)
ClashesNo ranking. Notify it at once, and the Project Manager states how to resolve it.Clause 17.1
A Scope change to resolve a clashIts Prices and dates are assessed on the reading that favours the Party that did not write the Scope.Clause 63.10
An illegal or impossible requirementNotify it. The Project Manager then instructs a change to the Scope.Clause 17.2
The PartiesOnly the Client and the Contractor, not the Project Manager or the Supervisor.Clause 11.2(13)
SubcontractingThe Contractor stays responsible, and each Subcontractor is accepted first.Clauses 26.1, 26.2
How everyone actsAs the contract states, with mutual trust and co-operation.Clauses 10.1, 10.2
Italics and capitalsItalics: a Contract Data entry. Capitals: a defined term.Clause 11.1
Reading and lawA singular word includes the plural. The law of the contract governs it.Clauses 12.1, 12.2
Changes not provided forBoth Parties agree it, confirm it in writing and sign it.Clause 12.3
AcceptanceIt never changes the Contractor's responsibility or its design liability.Clause 14.1
InstructionsFrom the Project Manager, the Supervisor or a notified delegate.Clauses 14.2, 27.3
  1. 1GeneralClauses 10 to 19
  2. 2The Contractor’s main responsibilitiesClauses 20 to 29
  3. 3TimeClauses 30 to 36
  4. 4Quality managementClauses 40 to 46
  5. 5PaymentClauses 50 to 53
  6. 6Compensation eventsClauses 60 to 66
  7. 7TitleClauses 70 to 74
  8. 8Liabilities and insuranceClauses 80 to 86
  9. 9TerminationClauses 90 to 93

The first digit of a clause number gives its section. Option clauses use the same numbers, so Option C clause 26.4 sits in section 2. The shaded sections hold most of this module's clauses.

Source: ECC 10.1, 10.2, 11.1, 11.2(13), 11.2(16), 11.2(18), 12.1, 12.2, 12.3, 14.1, 14.2, 17.1, 17.2, 26.1, 26.2, 27.3, 63.10.

Check your understanding

Five questions

Quiz
…

Source: see each answer.

Module 1 complete

You can now find your way round an ECC

Your quiz scoreNot taken yet

You can now

  • Name the parts of an ECC and where each rule sits.
  • Say what the Parties, the Project Manager and the Supervisor do.
  • Find an entry or a definition from italics and capitals.
  • Tell a change the contract allows from one that needs signatures.
  • Notify a clash and say how its change is assessed.

Independent course material. It is not published or endorsed by NEC. Clause references are to the NEC4 Engineering and Construction Contract, June 2017 with amendments January 2023. The project and the people are invented. Short quotes from NEC4 (© NEC 2017) and the FIDIC Red Book (© FIDIC 2017) are used for review and comment. Read the full clauses in your own copy of the contract.

Source: NEC4 Engineering and Construction Contract, June 2017 with amendments January 2023.