ECCEngineering and Construction Contract
The NEC4 contract for engineering and construction work with any level of Contractor design. It is the main contract these courses teach.
NEC4 Contract Preparation · Module 1 of 9
The NEC4 family: which contract for which relationship
After the River Aske floods 140 homes, Aldermere Water approves a GBP 11,200,000 relief scheme. Dana Whitfield, who will be its Project Manager, then maps who will contract with whom. Learn to pick the NEC4 contract for each line.
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 1Dana’s contract map, 29 January 2024
ClientAldermere Water
ECC
The worksECS, or ECSSSubcontracts
PSC
Design
ECSC
Boreholes
FC
Surveys and planting
TSC
Maintenance
DRSC
The Adjudicator
Each line is a contract with Aldermere Water. The subcontracts sit in the Contractor’s box because the Contractor signs them, not Aldermere Water.
Source: Aldermere contract map, 29 January 2024. NEC4 contract title pages.
Key terms
Eight NEC4 contracts you will meet in this module
Terms in this module
Tap a term with a dotted underline anywhere in the lesson to see its meaning.
ECSCEngineering and Construction Short Contract
A shorter NEC4 works contract for simple, low risk jobs. It has no main Options and pays through a Price List.
ECSEngineering and Construction Subcontract
The NEC4 subcontract for works under an NEC4 main contract. The Contractor also takes on the Project Manager's and Supervisor's roles towards the Subcontractor.
ECSSEngineering and Construction Short Subcontract
The short NEC4 works subcontract for simple, low risk work, under an ECC or an ECSC main contract.
PSCProfessional Service Contract
The NEC4 contract for appointing consultants such as designers or project managers. Its main Options are A, C and E.
TSCTerm Service Contract
The NEC4 contract for a service run over a set period, such as maintaining a road network for several years.
DBOCDesign Build and Operate Contract
The NEC4 contract where one contractor designs and builds an asset, then operates it for a service period.
FCFramework Contract
The NEC4 contract that appoints one or more suppliers for a term. Work is then ordered through work orders or time charge orders under other NEC4 contracts.
Source: NEC4 contract title pages and product pages. The course glossary.
The NEC4 family
Most purchases have a main contract, a short contract and a subcontract
Exhibit 2The NEC4 contracts by what is bought
| What is bought | Main contractThe Client buys | Short contractSimple, low risk work | SubcontractWork passed down |
|---|---|---|---|
| WorksBuild, with any level of design | ECC | ECSC | ECS, or ECSS |
| Professional servicesDesign and other consulting | PSC | PSSC | PSS |
| Term servicesUpkeep of an asset in use | TSC | TSSC | TSS |
| SupplyGoods, such as pumps | SC | SSC | No NEC4 form |
| Outside the gridExhibit 8 | DBOC · ALC · FC · DRSC | ||
Tap any name for its full title. Module 8 shows how to choose between the ECS and the ECSS.
Source: ECC and ECS title pages. NEC4 product pages.
The NEC4 family
Two Parties sign the ECC, and subcontracts pass work down
Exhibit 3The chain
Client · a PartyBuys the works
ECC
A main Option, A to F, sets how the Contractor is paid. It brings an Accepted Programme, an Early Warning Register and compensation events.
Project Manager · SupervisorNot Parties
Contractor · a PartyProvides the Works
ECS, or ECSS
The ECS mirrors the ECC, one level down.
- Still responsibleThe Contractor stays “responsible for Providing the Works as if it had not subcontracted” (26.1).
- Accepted firstSubcontractors need the Project Manager’s acceptance (26.2).
- DocumentsSent for acceptance, except for an NEC form amended only as the Z clauses require (26.3).
SubcontractorDoes part of the work
Source: ECC 11.2(13), 26.1, 26.2, 26.3, Schedule of Options. ECS 11.2(11), Schedule of Options.
The NEC4 family
NEC’s test for a short form is risk and complexity, not value
Exhibit 4Five jobs on NEC’s test
Easy to manageHard to manageHigher risk
ECC
GBP 300,000A job on a live railway
ECC
Lower riskGBP 8,600,000Aldermere’s works: ground, utilities, river
ECSC
GBP 48,000Quarrymoor’s three boreholes
GBP 3,000,000A simple job, design complete
ECC
GBP 240,000Footpaths phased around traffic
Signs of low risk: a finished design, known ground, few likely changes and no Others alongside.
| ECC | ECSC | |
|---|---|---|
| Project Manager and SupervisorIn the ECSC the Client manages and may delegate | Yes | No |
| Accepted ProgrammeECSC programme needs sit in the Scope | Yes | No |
| Early Warning Register | Yes | No |
| Main and secondary OptionsA Price List pays in the ECSC | Yes | No |
| Quotation sent with the notificationThe ECSC’s shorter procedure | No | Yes |
| Client’s liabilities are compensation eventsClause 60.1(14) in the ECC | Yes | No |
The ECSC’s programme requirements sit in its Scope. It pays through a Price List, and the Client carries the quantity risk on rated items. NEC’s July 2023 news adds that the weather compensation event differs.
Source: NEC ECSC product page. NEC comparison note, June 2023. NEC news, July 2023. ECC 60.1(14).
Quick check · The NEC4 family
Two questions on what you have just covered
Quick checkPick an answer to see if you are right and why
2 questions to answer
Source: ECC 26.1, 26.2, 26.3. NEC4 ECSC product page. NEC comparison note, June 2023.
Subcontractors
Three questions decide whether a firm is a Subcontractor
Exhibit 5The 11.2(19) test
- 1
Does it build or install any of the works?
If yes:A SubcontractorA piling firmIf no, go on to question 2. - 2
Does it design any of the works? Leave out “the design of Plant and Materials carried out by the supplier” (11.2(19)).
If yes:A SubcontractorA design consultantIf no, go on to question 3. - 3
Does it give a service in the Working Areas needed to Provide the Works? Leave out Equipment hire and people supplied and paid for their working time.
If yes:A SubcontractorSite securityIf no, go on to the outcome. - Not a SubcontractorA maker that only supplies Plant and Materials
One yes is enough, for a firm under contract to the Contractor.
Source: ECC 11.2(9), 11.2(14), 11.2(15), 11.2(19), 11.2(20), 26.2.
Subcontractors
Submit each Subcontractor for acceptance before appointing it
Exhibit 6A model submission
To: [name], Project Manager
From: the Contractor
Date: [date]
We submit [firm] as a proposed Subcontractor for [the work] (26.2).
Its subcontract is the NEC4 ECS, Option [letter], amended only as the additional conditions of contract require (26.3).
Amended further? Send the documents, without pricing information (26.3). Options C to F: send every subcontract’s pricing information (26.4).
Source: ECC 26.2, 26.3. ECC Options C to F, 26.4.
Services
Services follow the same pattern: a main form, a short form and a subcontract
Exhibit 7Which services contract fits?
Service 1 of 5
…
You placed…
PSC
- A project manager for a scheme with several stages, changes and interfaces.
PSSC
- A condition survey of 42 properties, charged by the time spent.
TSC
- Maintaining eleven pumping stations for five years, with one-off repairs as needed.
- Upkeep of a road network over a term, on a target with a price list.
TSSC
- A simple, low risk repair service, paid for priced items and rates.
The PSS and the TSS pass services work down. Module 9 picks the PSC and TSC main Options.
Source: ECC 21.1. NEC4 PSC, PSSC, TSC, TSSC and FMC product pages. NEC news, February 2024.
Other forms
Four forms and one Option join the parties in other ways
Exhibit 8Five other ways to join up the parties
DBOC · one contract
ClientOne contractor
- Design
- Build
- Operate for years
One contractor designs and builds the asset, then runs it.
Its main Options are A and C, each with a price list, and E, cost reimbursable. It runs what it built, so it answers for how the asset performs.
Dana rules it out, as Aldermere Water runs its own network.
ALC · one contract
ClientPartnerPartnerPartnerAlliance Board
The Client and several partners sign one contract.
It has no main Options. One pricing mechanism reimburses cost, with a performance regime on top. An Alliance Board takes decisions and hears disputes first.
Dana rules it out, as one main contractor can deliver the scheme.
X12 · shared objectives and targets
Own Contract
ClientDesigner
Own Contract
ClientContractor
Each firm keeps its own two-party contract, and X12 links them.
“An Own Contract is a contract between two Partners” (X12.1(3)). Payment for meeting a Key Performance Indicator target comes through each Own Contract (X12.4(1)).
The targets sit in the Schedule of Partners, which lists each Partner with its objectives and targets (X12.1(2)). X12 is not used with X20 (Schedule of Options).
FC · a set term
ClientSupplierSupplierSupplier
Work orderECC or ECSCTime charge orderPSSC
One or more suppliers for a set term, to work or supply when instructed.
Each order uses its own NEC4 contract. Work orders usually use the ECC or the ECSC, and time charge orders the PSSC.
Aldermere Water sets one up in 2025 for surveys, minor works and planting.
DRSC · one contract
ClientContractorAdjudicator
Both Parties appoint the Adjudicator under it.
It replaced NEC3’s Adjudicator’s Contract. Under W1 or W2 the Parties use the edition current at the starting date (W1.2(1), W2.2(3)).
A Dispute Avoidance Board under W3 is appointed the same way (W3.1(2)).
Source: ECC X12.1, X12.2, X12.4(1), W1.2(1), W2.2(3), W3.1(2), Schedule of Options. NEC news, April 2017.
Quick check · Subcontractors and other forms
Two questions on what you have just covered
Quick checkPick an answer to see if you are right and why
2 questions to answer
Source: ECC 11.2(19), 26.2, X12.1, X12.2, X12.4(1).
Your decisions
Three answers set the contracts around your own project
Exhibit 9Decide for your own project
Answer for a project of your own. Each answer shows why it fits, then what Aldermere Water chose.
0 of 3 decided
Your answers are kept while this page is open.
Which NEC4 contract will you use for the main works?
Judge it by risk and complexity, not by value.
Your answerECC
Full NEC management with a Project Manager, an Accepted Programme and six main Options. You commit to running its procedures and time limits for the whole job.
Your answerECSC
NEC offers the ECSC for simple, low risk work. It has no Project Manager and no main Options, so the Client runs it and pays through a Price List.
Your answerDBOC
One contractor designs, builds and then operates the asset, so it answers for how the asset performs. Most ECC questions in this builder will not apply.
Your answerALC
The Client and several partners sign one contract with shared targets and an Alliance Board. Most ECC questions in this builder will not apply.
At Aldermere
Aldermere Water chose: ECC: managed works with real risk
Aldermere Water chose the ECC because ground, utility and river risks needed its full early warning and compensation event procedures.
How will you buy design or other professional services?
Think about the size of the commission and how well you can define it.
Your answerPSC
The PSC suits a commission with stages, changes and interfaces to manage. You still choose how the consultant is paid, from Options A, C and E.
Your answerPSSC
NEC offers the PSSC for smaller commissions, paid by time charge or a price list. Its procedures are lighter than the PSC's.
Your answerNo consultant
No appointment to manage. Your own staff or the works Contractor carry the design, and the Scope must say which parts the Contractor designs (21.1).
At Aldermere
Aldermere Water chose: A PSC for a large or open brief
Aldermere Water appointed Harrowgill Consulting Engineers under a PSC in April 2024, because the brief ran from options to support during construction.
Who will look after the asset once it is in use?
Think about the years after handover, not just the defects date.
Your answerTSC
The TSC covers maintenance and repair of an operational asset over a fixed period, including one-off tasks. It offers main Options A, C and E.
Your answerTSSC
NEC offers the TSSC for simple, low risk maintenance. It pays for priced items and rates, with lighter procedures than the TSC.
Your answerExisting
No new procurement, but plan the handover. The works Scope should say what manuals, training and spares your people need before Completion.
Your answerIn the DBOC
Operation is part of the DBOC, so no separate maintenance contract is needed. Set the operating requirements in its Scope from the start.
At Aldermere
Aldermere Water chose: A term service contract (TSC)
Aldermere Water let a TSC to Selbrook Asset Services in June 2025 and will add the Mill Lane pumping station to it at take over.
Source: ECC title page, Schedule of Options. NEC4 product pages.
Your strategy
Module 1 fills in the first stage of your contract strategy
Exhibit 10Your contract strategy so far
- Module 1 · This moduleThe contract family0 of 3 decided
- Works contractNot decided yet
- Designer's contractNot decided yet
- MaintenanceNot decided yet
- Procurement strategyOpens in Module 2
- Main OptionOpens in Module 3
- Law and disputesOpens in Module 4
- Secondary OptionsOpens in Module 5
- Contract DataOpens in Module 6
- Scope and Site InformationOpens in Module 7
- Tenders and subcontractsOpens in Module 8
- The other contractsOpens in Module 9
DecidedNot decided yetOpens in a later moduleConflicts with another answer
Your answers are kept while this page is open.
Answers save in this browser. Each module adds a stage.
Source: ECC Schedule of Options.
On the project
Each line on Dana’s January 2024 map becomes a signed contract
Exhibit 11Aldermere Water’s contracts
ClientAldermere Water
PSCApril 2024
DesignHarrowgill Consulting Engineers LLP
ECSCJune 2024
BoreholesQuarrymoor Drilling Ltd
TSCJune 2025
MaintenanceSelbrook Asset Services Ltd
FCOctober 2025
Surveys, plantingThree framework suppliers
PSSCDecember 2025
SupervisorTom Barrow
ECCJanuary 2026
WorksThe winning tendererECS, or ECSSSubcontractors
DRSCBoth Parties
DisputesThe Adjudicator
Ruled outDBOCAldermere runs its own networkALCOne main contractor can deliver
Under W1 and W2 alike: “The Parties appoint the Adjudicator under the NEC Dispute Resolution Service Contract” (W1.2(1)), in the edition current at the starting date.
Source: Aldermere contract map, 29 January 2024. ECC W1.2(1), W2.2(3).
On the project
By August 2024 the designer is at work and the borehole logs are in
Exhibit 12January to August 2024
- 115 JanBudget approvedAldermere Water The board approves the scheme with a budget of GBP 11,200,000.
- 229 JanContract mapAldermere Water Dana Whitfield draws the contract map.
- 32 AprPSC signedHarrowgill PSC Aldermere Water signs a PSC with Harrowgill Consulting Engineers LLP for GBP 620,000.
- 410 JunECSC signedQuarrymoor ECSC Aldermere Water signs an ECSC with Quarrymoor Drilling Ltd for three boreholes on the culvert line, for GBP 48,000.
- 516 AugLogs issuedQuarrymoor ECSC Quarrymoor issues the factual logs of the three boreholes.
115 JanAldermere Water
…
With no Project Manager in the ECSC, Aldermere Water manages Quarrymoor itself. The logs later join the ECC’s Site Information.
Source: Aldermere Water, January to August 2024.
Quick check · On the project
Two questions on what you have just covered
Quick checkPick an answer to see if you are right and why
2 questions to answer
Source: NEC4 SC product page. ECC W1.2(1), W2.2(3).
Grey areas
Four questions practitioners ask when they draw the map
Exhibit 13Tap each question for a reasoned answer
The pump maker’s engineer commissions the pumps on Site. Is the maker now a Subcontractor?
It may be. Commissioning on Site can be a service in the Working Areas needed to Provide the Works. If in doubt, submit the maker for acceptance.
Clauses 11.2(19), 26.2
The Contractor hires a temporary works designer. Is it a Subcontractor?
Usually not. The design question is about the works, and temporary works are normally Equipment: items “the Scope does not require the Contractor to include in the works” (11.2(9)). If its staff give a service on Site, the third question may apply. The Project Manager can still ask for the design to be submitted for acceptance (23.1).
Clauses 11.2(9), 11.2(19), 23.1
A framework supplier plants the embankment beside the works Contractor. Is it a Subcontractor?
No. A Subcontractor is under contract to the Contractor, but this supplier’s contract is with Aldermere Water. Under the ECC it is one of the Others (11.2(12)). Module 9 shows how the two contracts meet.
Clauses 11.2(12), 11.2(19)
Should the Supervisor be appointed under a PSC or a PSSC?
The ECC does not say. Contract Data part one names the Supervisor, who is not a Party (11.2(13)). One inspector paid for time suits the PSSC. A team with its own procedures suits the PSC. Aldermere Water appoints Tom Barrow under a PSSC on 1 December 2025.
Clause 11.2(13)
Source: ECC 11.2(9), 11.2(12), 11.2(13), 11.2(19), 23.1, 26.2.
Going further
What changed from NEC3, and why term work needs a term form
Exhibit 14For the experienced reader
2017New forms
NEC4 brought the DBOC in 2017 and the ALC in 2018, and the PSC lost NEC3’s Option G, its term contract. Employer became Client, and Works Information became Scope.
X8 to X11X Options filled
NEC4 filled NEC3’s empty X8 to X11, and added X21 and X22.
2013Atkins Ltd v Secretary of State for Transport
Lump sum highway upkeep: the amended clause tested each pothole alone, so extra potholes were no compensation event.
DBOCOr two contracts
One DBOC firm answers for years of operation. An ECC then a TSC leaves the handover to the Client.
Source: ECC Schedule of Options. NEC3 ECC Schedule of Options. Atkins Ltd v Secretary of State for Transport (2013).
Watch out
Six mistakes to avoid
Exhibit 15Common mistakes
Test the ECSC first.
NEC ECSC product pageJudge risk and complexity instead.
NEC note, June 2023Test it against all three questions.
ECC 11.2(19)Its documents then need acceptance.
ECC 26.3Use a term form, like the TSC.
Atkins (2013)List their manuals, training and spares in the works Scope.
ECC 11.2(2)Source: ECC 11.2(2), 11.2(16), 11.2(19), 26.3. NEC4 ECSC product page. NEC comparison note, June 2023.
Summary
Every rule in this module, and where to find it
Exhibit 16The rules at a glance
| Topic | What NEC4 says |
|---|---|
| The ECC | A works contract with any level of design, on one main Option from A to F. Its Parties: the Client and the Contractor. Title page, Schedule of Options, 11.2(13) |
| The ECS | A works subcontract below an NEC4 main contract, on Options A to E. Its Parties: the Contractor and the Subcontractor. ECS 11.2(11) |
| Subcontracting | The Contractor stays responsible. The Project Manager accepts each Subcontractor before it is appointed. Clauses 26.1, 26.2 |
| Subcontract documents | Sent for acceptance, without pricing information. Not needed for an NEC contract amended only as the Z clauses require, or if the Project Manager agrees. Under Options C to F, the pricing information of every subcontract goes in as well, unless the Project Manager agrees otherwise. Clauses 26.3, 26.4 |
| Who is a Subcontractor | A firm under contract to the Contractor that builds or installs, designs, or gives a needed service in the Working Areas. Left out: a supplier’s design of its Plant and Materials, Equipment hire, and people supplied and paid for their working time. Clause 11.2(19) |
| Short forms | Simple, low risk work that is easy to manage, with no value limit. The ECC treats a Client’s liability as a compensation event, and the ECSC does not. NEC product pages, 60.1(14) |
| No consultant | The Scope must name any part the Contractor is to design. Clause 21.1 |
| X12 | Shared targets laid over two-party Own Contracts. Not used with X20. Clauses X12.1, X12.2 |
| The Adjudicator | Under W1 or W2, both Parties appoint it under the DRSC current at the starting date. Clauses W1.2(1), W2.2(3) |
Source: ECC 11.2(13), 11.2(19), 21.1, 26.1, 26.2, 26.3, 60.1(14), W1.2(1), W2.2(3), X12.1, X12.2. ECS 11.2(11).
Check your understanding
Five questions
Quiz
Source: see each answer.
Module 1 complete
You can now map the contracts a scheme needs
Your quiz scoreNot taken yet
You can now
- Name the NEC4 contracts, their short forms and subcontracts, and the relationship each one is for.
- Use NEC’s test of risk and complexity to choose between the ECC and the ECSC.
- Test whether a firm is a Subcontractor, and submit it for acceptance.
- Draw the map of contracts one scheme needs, from design to maintenance.
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, unless another NEC4 contract is named. 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 contracts, June 2017 with amendments January 2023.