TEMPORARY WORKS CONSULTING & DESIGN LTD

Temporary works responsibilities & risk

NEC Contract Master · 9 September 2026

Temporary works: responsibilities and risk mitigation

General learning, with Great Britain construction examples. No executed project contract has been supplied. NEC3 and NEC4 must be checked separately, including their publication dates, incorporated amendments, Options, Z clauses and document precedence. References below verify published guidance or identified amendment wording; they do not verify your project obligations. Practical controls are original recommendations to allocate and agree in the project documents.

ECC — main works contract

Contract chain: Client/Employer ↔ Contractor; Project Manager administers the contract within the authority actually given.

NEC3 / NEC4 check: NEC3 ECC: identify the publication/revision and Works Information. NEC4 ECC: June 2017 baseline; check January 2019, October 2020, January 2023 and any later incorporated amendments; use Scope.

Reference position: Published references: ECC clauses 21.1, 21.2, 23.1 and 14.1. The 2018 article explains NEC3/NEC4; the undated acceptance FAQ uses NEC3 terminology. Verify each against the signed contract.
TW01 · Design of equipment in the ECC
TW02 · Design acceptance — NEC FAQ
TW04 · NEC4 Engineering and Construction Contract

Responsibilities, risk and mitigation — ECC — main works contract
Role / process	Position to establish	Risk	Practical mitigation	Direct references
Contractor — design allocation	For works design, examine the parts allocated by Works Information/Scope (21.1). Establish separately whether the support is Equipment.	A missing drawing is mistaken for an automatic employer/client design obligation.	Prepare an item-by-item design boundary: purpose, loads, permanent-works interfaces, designer, checker and removal conditions.	TW01 · Design of equipment in the ECC
Contractor / Project Manager — design submission	Works-design particulars required by the contract follow 21.2; Equipment submissions follow 23.1. Acceptance does not transfer design responsibility (14.1).	Every temporary support is assumed to have the same acceptance hold point.	List required submissions, review periods and agreed release conditions. Keep engineering approval, contractual acceptance and site permission to load separate.	TW01 · Design of equipment in the ECC TW02 · Design acceptance — NEC FAQ
Authorised contract administrator — change	A TWC’s engineering concern is not by itself proof of contractual instruction or compensation-event entitlement.	Safety action, a method change and a client change are merged into one claim.	Make the area safe; log the event and original obligation, confirm authority, and check the actual early-warning and compensation-event routes separately.	TW01 · Design of equipment in the ECC TW18 · Temporary works FAQs TW16 · CDM 2015 — Regulation 19: Stability of structures

Original example: Hypothetical: a revised transformer route needs a stronger working platform. Compare the original route, plant reactions and Scope with the revision before deciding whose risk it is. Immediate restrictions on platform use are a separate safety decision.

Documents that resolve the position: Executed ECC; both parties’ Scope/Works Information; the item’s classification; design/submission provisions; instruction/delegation records; Accepted Programme; notification provisions and relevant Options.

ECS — works subcontract

Contract chain: Contractor ↔ Subcontractor. Verify the contractual recipient under the subcontract; the main-contract Project Manager is not automatically the subcontract administrator.

NEC3 / NEC4 check: NEC3 ECS uses the actual Subcontract Works Information. NEC4 ECS uses Subcontract Scope. Verify the publication and amendments of both main contract and subcontract independently.

Reference position: NEC’s ECS catalogue confirms any level of design and Options A–E. The operative design, Equipment, acceptance and notice clauses must be checked in the executed ECS; ECC numbering is not treated as proof.
TW05 · NEC4 Engineering and Construction Subcontract
TW03 · Submission of deliverables under the PSC

The precise contractual provision has not been verified; the following is a provisional analysis pending the relevant wording.

Responsibilities, risk and mitigation — ECS — works subcontract
Role / process	Position to establish	Risk	Practical mitigation	Direct references
Contractor / Subcontractor — package boundaries	Identify which temporary works, interfaces and design deliverables the subcontract actually includes.	Main-contract duties are assumed to have passed down automatically.	Use a subcontract responsibility schedule: who supplies ground data, designs the platform, designs the lift and checks adjacent structures. Identify any retained Contractor duty.	TW05 · NEC4 Engineering and Construction Subcontract
Subcontractor — notices and submissions	Use the ECS communication route and the periods in that subcontract.	A notice sent only to the main-contract Project Manager fails to reach the required recipient.	Maintain separate main-contract and subcontract registers. Allow time for the Contractor’s review and onward submission; record each actual service and receipt.	TW03 · Submission of deliverables under the PSC TW05 · NEC4 Engineering and Construction Subcontract
Contractor — retained interface management	Align the package with other subcontractors, the site sequence and applicable safety arrangements.	The design is sound in isolation but incompatible with another package.	Review cross-package loads and handovers before release. Acceptance, checking and subcontracting are recorded as distinct actions; do not infer a complete liability transfer.	TW22 · Principal contractors: roles and responsibilities TW05 · NEC4 Engineering and Construction Subcontract

Original example: Hypothetical: a scaffold subcontract excludes foundations while a civils package excludes scaffold support. Resolve the gap in written allocations before erection; compare changes against each signed subcontract.

Documents that resolve the position: Executed ECS and main contract; subcontract information/Scope; exclusions; flow-down schedule; design standard; notice route; agreed check/review periods; site coordination plan.

PSC / NEC4 PSS — professional services

Contract chain: Client/Employer ↔ Consultant under PSC, or the parties identified in the NEC4 PSS. A temporary works designer, checker, TWC and site inspector are separate appointments or separately defined services.

NEC3 / NEC4 check: Both NEC3 PSC and NEC4 PSC use Scope. NEC3 PSC administration must be checked in its own wording; NEC4 introduces the named Service Manager role. A published NEC4 PSS is distinct from a NEC3 PSC adapted for subcontract use.

Reference position: NEC4 PSC clause 20.1 is identified in NEC’s 2020 guidance. NEC3 submission arrangements are explained in the 2016 deliverables article. Verify the exact skill-and-care, design-liability, acceptance and instruction wording in the signed appointment.
TW03 · Submission of deliverables under the PSC
TW06 · NEC4 Professional Service Contract
TW07 · NEC4 Professional Service Subcontract
TW24 · How to ensure that bid-winning supply chains actually get used

The precise contractual provision has not been verified; the following is a provisional analysis pending the relevant wording.

Responsibilities, risk and mitigation — PSC / NEC4 PSS — professional services
Role / process	Position to establish	Risk	Practical mitigation	Direct references
Consultant — defined professional service	Start with the commissioned deliverables and express responsibilities in Scope.	A design-only fee is treated as covering coordination, site supervision and every later modification.	List calculations, drawings, check certificates, design-risk information, visits, assumptions, exclusions and who commissions changes. Confirm the governing design standard and liability terms.	TW03 · Submission of deliverables under the PSC TW24 · How to ensure that bid-winning supply chains actually get used
Appointing party / Consultant — information and review	State what information the designer needs and how deliverables are submitted and reviewed.	Late steel reactions or ground data arrive after the promised design date.	Create an information schedule and submission matrix with revision, owner, needed-by date and response route; record effects on resources and programme.	TW03 · Submission of deliverables under the PSC
Designer / checker / TWC — distinct services	CDM designer duties arise from design activity; coordination does not automatically sit with the design engineer.	A check certificate is treated as a site inspection or permission to load.	Issue separate signed appointments and check scopes. Identify the site person who verifies installation, records inspections and authorises use under the agreed procedure.	TW18 · Temporary works FAQs TW20 · Designers: roles and responsibilities

Original example: Hypothetical: David is appointed to design generator-hall propping from supplied reactions. A request to verify every installed prop and act as TWC needs its own scope/authority assessment; it is not automatically included or automatically a payable change.

Documents that resolve the position: Signed PSC/PSS and Scope; amendments; skill-and-care/performance duties; insurance wording and exclusions; deliverable and information schedules; site-services appointment; instructions and notice provisions.

TSC / NEC4 TSS — term services

Contract chain: Client/Employer ↔ Contractor for an ongoing service, with the Service Manager; identify the separate chain if an NEC4 TSS is used.

NEC3 / NEC4 check: NEC3 TSC uses Service Information; NEC4 TSC uses Scope. Check the form’s plan and task mechanisms; do not assume the ECC Accepted Programme and Completion mechanisms apply unchanged.

Reference position: NEC’s NEC4 TSC description confirms maintenance/repair services and tasks. Its Option list does not include standard X15. Operative Equipment-design, acceptance and task provisions have not been verified for a supplied contract.
TW08 · NEC4 Term Service Contract
TW09 · Which NEC4 contract?

The precise contractual provision has not been verified; the following is a provisional analysis pending the relevant wording.

Responsibilities, risk and mitigation — TSC / NEC4 TSS — term services
Role / process	Position to establish	Risk	Practical mitigation	Direct references
Contractor — service and temporary support	Determine whether the service includes access, emergency support, design, inspections and removal.	Recurring service obligations are confused with additional task work.	Define service boundaries, response cover and task-specific deliverables. Price and plan specialist temporary works explicitly where required.	TW08 · NEC4 Term Service Contract
Service Manager / asset operator — authority	Distinguish contract instructions from operational outages, access permissions and electrical isolations.	A site operator’s access decision is treated as a contractual instruction.	Maintain an authority and outage matrix, record access commitments and identify the authorised contract communication for each change.	TW08 · NEC4 Term Service Contract
Contractor / designer — design risk	An ECC design-liability Option must not be assumed to apply to TSC design.	A design promise exceeds the designer’s appointment or insurance.	Review the actual design standard and insurance with the adviser and broker; specify compatible temporary support, inspection and release duties in the service documents.	TW08 · NEC4 Term Service Contract TW20 · Designers: roles and responsibilities

Original example: Hypothetical: substation maintenance needs temporary cable-trench support during an outage. Confirm the service/task boundary, network permissions, design loads and safe reinstatement before assessing additional time or cost.

Documents that resolve the position: Signed TSC/TSS; Service Information/Scope; applicable task documents; plan and task programme; Affected Property and access arrangements; design/insurance amendments; service authority and notice routes.

ECSC / ECSS — short works forms

Contract chain: Client ↔ Contractor under ECSC; Contractor ↔ Subcontractor under ECSS. Read the named roles in the actual edition.

NEC3 / NEC4 check: NEC3 short forms and pre-amendment NEC4 short forms must not be credited with the January 2023 optional protection automatically. NEC4 June 2017 amended January 2023 adds clause 83.4 and linked Data selections.

Reference position: Official January 2023 amendment wording verified: ECSC pp. 26–27 and ECSS pp. 29–30, including clause 83.4. Its use depends on the incorporated amendment and relevant Contract/Subcontract Data entry.
TW09 · Which NEC4 contract?
TW10 · NEC4 January 2023 Contract Amends
TW11 · NEC4 2023 amendments now available

Responsibilities, risk and mitigation — ECSC / ECSS — short works forms
Role / process	Position to establish	Risk	Practical mitigation	Direct references
Contracting parties — suitability and allocation	Short forms are intended for lower-risk, simpler work; temporary does not mean low risk.	Complex support is procured under an under-specified short agreement.	Assess consequences of failure, interfaces and management needs. Define the complete design–install–inspect–remove package or choose a more suitable form before award.	TW09 · Which NEC4 contract?
Designer’s contracting party — design standard	The 2023 clause 83.4 can apply a professional skill-and-care standard when the relevant Data says so, with linked insurance.	Everyone assumes a standard X15 selection or a retrospective liability reduction.	Check the signed Yes/No selection, amendment, insurance amount and period. Record the agreed design duty and any bespoke change.	TW10 · NEC4 January 2023 Contract Amends
Named contract recipient — administration	Verify the short form’s own notice, instruction and payment provisions.	Long-form ECC processes are copied into a short contract.	Use a short-form-specific notice route and an agreed installation/release record; verify every required period before entering a due date.	TW09 · Which NEC4 contract? TW11 · NEC4 2023 amendments now available

Original example: Hypothetical: a small-value propping job supports an occupied building. Its fee alone does not demonstrate suitability for a short form. Resolve the design standard and installation/inspection responsibilities before starting.

Documents that resolve the position: Actual ECSC/ECSS edition; January 2023 incorporation evidence; clause 83.4 Data choice; insurance; Scope; named recipients; exact notice and safety-release provisions.

PSSC / TSSC — short services

Contract chain: Identify the Consultant or service Contractor, the appointing party and the named communication recipient in the actual short form.

NEC3 / NEC4 check: Check NEC3/NEC4 separately. PSSC is a professional service appointment; TSSC is a term service appointment. They are not interchangeable and do not acquire all long-form PSC/TSC mechanisms.

Reference position: The NEC4 selection guide and PSSC catalogue establish intended use. No operative PSSC/TSSC design, liability, task or notice clause is verified here.
TW09 · Which NEC4 contract?
TW12 · NEC4 Professional Service Short Contract
TW26 · NEC3 Term Service Short Contract

The precise contractual provision has not been verified; the following is a provisional analysis pending the relevant wording.

Responsibilities, risk and mitigation — PSSC / TSSC — short services
Role / process	Position to establish	Risk	Practical mitigation	Direct references
Appointing party / provider — service boundary	Distinguish a design/checking commission from physical maintenance or installation.	A short scope leaves site attendance and residual-risk information unallocated.	Specify outputs, site involvement, necessary information, checking, exclusions and change instructions in plain terms.	TW12 · NEC4 Professional Service Short Contract TW20 · Designers: roles and responsibilities
Appointing party — proportionate form choice	Lower administration burden does not establish low engineering consequence.	Safety-critical work is treated as routine because it is quick or inexpensive.	Review complexity, occupied areas, energy interfaces and failure consequences before selecting or retaining the short form.	TW09 · Which NEC4 contract?
Provider — administration and evidence	Read this form’s own Scope or Service Information, pricing documents and conditions.	Long-form entitlements, review periods or Options are assumed.	Record the agreed service, actual information dates and instructed changes; use the specific short-form communication and payment process.	TW12 · NEC4 Professional Service Short Contract TW26 · NEC3 Term Service Short Contract

Original example: Hypothetical: a brief crane-pad check is commissioned under PSSC while the site expects continuing inspection after heavy rain. Allocate that monitoring service expressly and check whether the chosen appointment remains suitable.

Documents that resolve the position: Signed PSSC/TSSC, edition and amendments; service description; price list; information assumptions; site attendance and monitoring scope; design standard; liability and insurance; exact notice clauses.

SC / SSC — supply contracts

Contract chain: Purchaser ↔ Supplier. Confirm the actual goods and associated services and the precise delivery/installation boundary.

NEC3 / NEC4 check: Read NEC3 SC/SSC and NEC4 SC/SSC independently. Preserve the actual Goods Information / Scope terminology. NEC4 SC is a priced goods contract; SSC is a simpler goods form. Neither is the ECC works contract merely because the goods are used in construction.

Reference position: Official NEC4 SC/SSC descriptions verified. Exact design, delivery, title, risk, testing and notice provisions require the supplied purchase contract and any incorporated delivery terms.
TW13 · NEC4 Supply Contract
TW14 · NEC4 Supply Short Contract
TW25 · NEC3 Supply Contract

The precise contractual provision has not been verified; the following is a provisional analysis pending the relevant wording.

Responsibilities, risk and mitigation — SC / SSC — supply contracts
Role / process	Position to establish	Risk	Practical mitigation	Direct references
Purchaser / Supplier — design and delivery boundary	Identify who supplies product data and any site-specific design or associated service.	Supply of props, mats or a transformer is mistaken for design of the complete temporary arrangement.	Agree loads, reactions, centre of gravity, lifting points, component limits and the person who designs support, offloading and erection.	TW13 · NEC4 Supply Contract TW20 · Designers: roles and responsibilities
Purchaser / receiving contractor — site interface	Confirm who provides access, crane support, working platforms and temporary restraints.	The delivery arrives before the site is structurally ready.	Set a documented readiness review using supplier data, checked site design, access survey and the asset operator’s permissions.	TW13 · NEC4 Supply Contract TW16 · CDM 2015 — Regulation 19: Stability of structures
Both parties — commercial risk boundary	Check incorporated delivery terms rather than inferring risk transfer from physical arrival.	Damage, waiting time or re-delivery is allocated without checking the agreement.	Record delivery condition, responsibilities, readiness dates and storage/inspection evidence. Verify the actual event and notification route before asserting entitlement.	TW13 · NEC4 Supply Contract TW14 · NEC4 Supply Short Contract

Original example: Hypothetical: transformer dimensions change before delivery. Establish whether the Supplier changed the goods, the Purchaser changed the requirement or the original site support was inadequate; each explanation needs different evidence.

Documents that resolve the position: SC/SSC and amendments; Goods Information/Scope as named in the actual form; drawings/data revision; associated services; incorporated delivery terms; design/testing duties; title/risk and insurance provisions; receiving works contract and notice process.

Safety duties and project appointments

Legal requirement: CDM 2015 regulation 19 requires suitable structural stability and temporary supports that withstand foreseeable loads and are used for their designed purpose. Stop or restrict unsafe work through the site’s safety arrangements while the commercial position is investigated. TW16 · CDM 2015 — Regulation 19: Stability of structures

The following matrix separates legal duties, published guidance and proposed management controls. A person can hold more than one role, but each appointment, competence and authority still needs to be recorded.

Who acts, what they control and when
Role	Duty / basis	Practical action and evidence	When	Direct references
Client / Employer	Legal dutyholder and contracting party must be identified separately. Provide the agreed project information and arrange appropriate roles.	Name the CDM appointments and each contractual design package; fund enough time for information, design and checking.	Before procurement and whenever appointments or interfaces change.	TW17 · Managing health and safety in construction — L153 TW21 · Principal designers: roles and responsibilities
Permanent and temporary works designers	CDM 2015 regulation 9 applies to design activity, including temporary works. Address foreseeable design risks so far as reasonably practicable and communicate remaining risks.	Record stage loads, assumptions, support reactions and design changes; coordinate where one design relies on another.	With each design issue and before a changed arrangement is used.	TW17 · Managing health and safety in construction — L153 TW20 · Designers: roles and responsibilities
Principal designer under CDM	Regulation 11 concerns pre-construction health-and-safety coordination, including continuing design during construction.	Maintain a design-interface review and pass relevant risk information between designers and the principal contractor.	During design planning and whenever new design or interface risks arise.	TW17 · Managing health and safety in construction — L153 TW21 · Principal designers: roles and responsibilities
Principal contractor / installing contractor	Regulation 13 gives the principal contractor construction-phase management and coordination duties. Regulation 19 addresses structural stability and support loading.	Plan the installation/removal sequence, brief the workforce, verify the actual installation, restrict use and arrange required inspections.	Before installation and first use; throughout use, alteration and removal.	TW17 · Managing health and safety in construction — L153 TW16 · CDM 2015 — Regulation 19: Stability of structures TW22 · Principal contractors: roles and responsibilities
Designated Individual / TWC / TWS	Procedural responsibilities arise from the adopted procedure and actual appointment. HSE distinguishes coordination from the design commission.	Record authority, competence, deputies, item register, design briefs, check status, inspections and permission-to-load/use/remove arrangements.	Appoint before the activity; review on personnel, design, sequence or site changes.	TW18 · Temporary works FAQs TW19 · BS 5975-1:2024 — Temporary works: management procedures
Design checker / site inspector	A design check, construction inspection and contractual acceptance answer different questions. The required scope and independence must be established.	Specify each review’s limits and deliverables. Close check comments and installation discrepancies before the agreed release; retain signed evidence.	At the required design and construction hold points.	TW19 · BS 5975-1:2024 — Temporary works: management procedures TW23 · Structural stability during alteration, demolition and dismantling
Project Manager / Service Manager / authorised recipient	Contract authority depends on the applicable NEC form and delegation. A technical acceptance or TWC direction is not evidence of every commercial authority.	Maintain a written delegation and communication matrix; record instructions, submissions and notices in their correct routes.	Verify before relying on an instruction or sending a contractual notice.	TW02 · Design acceptance — NEC FAQ TW08 · NEC4 Term Service Contract TW03 · Submission of deliverables under the PSC

Standard edition: BSI identifies BS 5975-1:2024 as the current management-procedure part. Check the edition incorporated into the contract and the procedure actually adopted. No proprietary clauses or check-category rules are reproduced here. TW19 · BS 5975-1:2024 — Temporary works: management procedures

Who carries the cost risk?

The ECC main Option changes the payment and cost-risk model. Design allocation still needs its own check. The published baseline below is NEC4 ECC. Verify the applicable NEC3 text separately; other families have different Options. TW04 · NEC4 Engineering and Construction Contract

ECC payment model and temporary-works risk control
Main Option	Published payment model	Original practical recommendation
ECC Option A	Priced contract with activity schedule.	Price foreseeable temporary works within the agreed work; identify design and access assumptions. An overrun alone does not establish an adjustment.
ECC Option B	Priced contract with bill of quantities.	Check measurement and pricing rules for temporary works, including whether they are separately itemised. Quantity risk and design responsibility are different questions.
ECC Options C / D	Target contract with activity schedule / bill of quantities.	Maintain the accepted baseline, eligible cost records and target-change evidence. Cost sharing does not remove notice, safety or design duties.
ECC Option E	Cost-reimbursable contract.	Check the applicable Defined Cost, Fee and disallowed-cost provisions. Record authorisation and causation; expenditure is not automatically recoverable.
ECC Option F	Management contract.	Make subcontract and retained design interfaces explicit. Review package procurement, reimbursement provisions and site coordination together.

Design liability: NEC4 ECC June 2017 Option X15.1, where included, addresses liability for design-related Defects using a professional skill-and-care test. Check its actual wording, amendments and interaction with performance requirements. Do not assume NEC3 X15 has identical wording, that Equipment is covered in the same way, or that insurance covers every promised result. TW15 · Understanding defects under NEC

Short-form distinction: NEC4 ECSC/ECSS clause 83.4 was added by the January 2023 amendments, with an express Data choice and insurance provisions. Verify inclusion and selection. TW10 · NEC4 January 2023 Contract Amends

Term-service distinction: The NEC4 TSC standard Option list does not include X15. Any design limitation must be established from the actual TSC and amendments. TW08 · NEC4 Term Service Contract

Make risk reduction observable

These are original practical recommendations, not additional terms automatically imposed by NEC. Assign a named owner, agree the required record and use the actual contractual or safety deadline.

Risk, owner, evidence and action point
Risk	Owner to agree	Control / evidence	When
Unallocated temporary stability	Contract lead + designers	An item schedule identifying purpose, design owner, checker, installation owner, monitoring and removal criteria.	Before tender/appointment; revisit when Scope or method changes.
Incomplete design inputs	Information owner + designer	Signed design brief; current loads/reactions, ground data, utilities, permanent-works limits and agreed assumptions.	Before design release; reopen if inputs change.
Unsafe use or alteration	Installing contractor + appointed coordinator	Inspection/release record; load limits; restrictions; change control and escalation. A commercial dispute never releases a safety hold point.	Before loading or alteration, and at the applicable inspection triggers.
Late approvals or information	Contract manager + planner	Submission and information schedule linked to programme logic, review durations, access and outage windows.	Set before work; update on each event and programme revision.
Uninsured design promise	Contracting party + insurance broker + legal adviser	Compare the complete design obligation, X15 where available/selected, warranties, indemnities, caps and insurance exclusions. Record any gap.	Before signing and on material scope/terms changes.
Loss of a contractual right	Authorised sender + commercial lead	Separate early warning and event/notice assessment; verified trigger, period, service route, deadline, recipient and receipt evidence.	Immediately on discovery; use the actual contract deadline.
Disputed cost or delay	Commercial lead + planner + site team	Contemporaneous event record, instruction, design revision, resources, programme impact and alternative-cause assessment.	Start at the event; keep records while the effects develop.

Counterargument check: Before asserting a change, test original scope obligation, defective design, contractor method change, instructed change, inaccurate information, restricted access and late information. State which documents support and weaken each explanation.

Specialised forms: NEC4 ALC, DBOC and facilities-management forms, Framework Contract call-offs and bespoke appointments need their own intake. Do not extend this matrix to them without the actual form. TW09 · Which NEC4 contract?

References and verification limits

Checked 9 September 2026. Free public guidance/catalogues are linked; operative NEC contracts and BS standards require appropriate licensed access. Only the identified official amendment provisions were read as contract wording. No supplied executed contract has been analysed.

TW01 · Design of equipment in the ECC

Richard Patterson and Rob Horne / NEC · 16 May 2018 · Published guidance

NEC3/NEC4 ECC; sections “Who designs what?”, “What designs have to be submitted for acceptance?” and “What if the project manager does not accept a design?”. Public explanation of clauses 21.1, 21.2 and 23.1.

Limit: Predates later NEC4 amendments. The article’s separate stop-work clause reference is not adopted here. Check the signed form and amendments.

TW02 · Design acceptance — NEC FAQ

NEC · Undated; checked 9 September 2026 · Published guidance

ECC example uses NEC3 terminology, Works Information: clauses 21.2 and 14.1; submissions and continuing design responsibility.

Limit: Publication edition/revision not stated. An FAQ does not verify a project’s executed wording.

TW03 · Submission of deliverables under the PSC

Richard Patterson / NEC · 19 August 2016 · Published guidance

NEC3 ECC, ECS and PSC design interfaces; sections on defining deliverables, submission times and response times in PSC Scope.

Limit: NEC3 guidance, before NEC4. Do not transfer its clause numbers or suggested clauses to NEC4 PSC.

TW04 · NEC4 Engineering and Construction Contract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description and Main Option Clauses: ECC design flexibility and Options A–F.

Limit: Public catalogue read; paid operative contract not accessed. Main Option does not by itself allocate every design duty.

TW05 · NEC4 Engineering and Construction Subcontract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description: works subcontract, design flexibility, Options A–E; secondary Options include X15 and X18.

Limit: Public catalogue read. Actual Subcontract Scope, amendments and notice provisions require the signed ECS.

TW06 · NEC4 Professional Service Contract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description, Consultant’s main responsibilities and Options A, C and E.

Limit: Catalogue only; it does not establish the services or design standard in David’s appointment.

TW07 · NEC4 Professional Service Subcontract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description: professional services subcontract to a consultant or contractor; Options A, C and E may differ from the main contract.

Limit: Catalogue only. Do not describe a bespoke NEC3 PSC subcontract as the published NEC4 PSS.

TW08 · NEC4 Term Service Contract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description, main Options A/C/E and secondary Option list. X15 is not a standard TSC secondary Option.

Limit: Public catalogue only. Operative Equipment, plan, Task Order and notice clauses require the actual form. Check NEC3 separately.

TW09 · Which NEC4 contract?

NEC · Undated; checked 9 September 2026 · Published guidance

Works, professional/term/facilities services and supply; short forms are intended for lower risk and complexity.

Limit: Selection overview, not a clause source or a project suitability assessment.

TW10 · NEC4 January 2023 Contract Amends

NEC · January 2023 · Official amendment wording

PDF pp. 26–27: ECSC Contract Data and clause 83.4; pp. 29–30: ECSS Subcontract Data and clause 83.4. Optional design standard and linked insurance.

Limit: Applies only when this amendment and the relevant Data selection form part of the contract. No retrospective incorporation assumed.

TW11 · NEC4 2023 amendments now available

NEC · 9 February 2023 · Published guidance

Section on limiting contractor design liability in ECSC and ECSS.

Limit: Summary of amendments, not evidence of their selection in any existing agreement.

TW12 · NEC4 Professional Service Short Contract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description and Contract Forms: professional service, Scope and price list.

Limit: Catalogue only; do not import long-form PSC processes or assume complexity is low because the fee is small.

TW13 · NEC4 Supply Contract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description and core clauses: goods, associated services, delivery and priced contract; Incoterms may be incorporated.

Limit: Catalogue only. It does not allocate offloading, cranage, ground support or temporary stability on a particular purchase.

TW14 · NEC4 Supply Short Contract

NEC · June 2017 suite; revised January 2023 catalogue · Publisher reference

Description: simpler, lower-risk goods, single or batch orders.

Limit: Catalogue only. Do not treat supply of proprietary components as a complete site-specific temporary works design.

TW15 · Understanding defects under NEC

NEC · 2 February 2018 · Published guidance

Opening section discusses NEC4 ECC June 2017, Option X15.1 and design-related Defects.

Limit: Predates later amendments. Used only for the X15 design-standard explanation, not for an unreviewed case-law proposition.

TW16 · CDM 2015 — Regulation 19: Stability of structures

UK legislation / The National Archives · SI 2015/51; current text checked 9 September 2026 · Legal requirement

Regulation 19(1)–(3): stability, foreseeable loading of supports and safe use.

Limit: Great Britain construction context; establish territorial application. Northern Ireland and overseas duties require separate verification.

TW17 · Managing health and safety in construction — L153

Health and Safety Executive · 2015 · Legislation reproduced with HSE guidance

p. 26: regulation 9 and guidance paragraph 72; pp. 30–31: regulation 11; pp. 36–37: regulation 13; p. 51: regulation 19.

Limit: Original 2015 text and guidance; current HSE dutyholder pages cross-checked. Guidance is distinct from the reproduced regulations.

TW18 · Temporary works FAQs

Health and Safety Executive · Live page checked 9 September 2026 · Published regulator guidance

Answers on coordinating temporary works and the designer/TWC distinction.

Limit: Some legacy standard references remain on HSE pages. Use BSI’s current catalogue to identify the 2024 parts; do not treat a TWC title as statutory appointment language.

TW19 · BS 5975-1:2024 — Temporary works: management procedures

British Standards Institution · 31 December 2024 · Standard / published guidance

Current catalogue: management procedures; together with Part 2 replaces BS 5975:2019.

Limit: Paid standard; catalogue/overview checked, full clauses not read. No BS clause numbers or mandatory check categories asserted. Confirm the edition incorporated into the project.

TW20 · Designers: roles and responsibilities

Health and Safety Executive · Live page checked 9 September 2026 · Published regulator guidance

Design-risk reduction and information exchange, including temporary works design activity.

Limit: General GB guidance; appointment scope and contractual liability remain separate.

TW21 · Principal designers: roles and responsibilities

Health and Safety Executive · Live page checked 9 September 2026 · Published regulator guidance

Planning, managing, monitoring and coordinating pre-construction health and safety.

Limit: CDM principal designer is a distinct role; an NEC title does not establish the appointment.

TW22 · Principal contractors: roles and responsibilities

Health and Safety Executive · Live page checked 9 September 2026 · Published regulator guidance

Construction-phase coordination, contractor cooperation and safe planning.

Limit: GB duties; distinguish the statutory role from the NEC Contractor and the TWC.

TW23 · Structural stability during alteration, demolition and dismantling

Health and Safety Executive · Live page checked 9 September 2026 · Published regulator guidance

Competent assessment; bracing/propping design, installation, checks, inspection, maintenance and removal.

Limit: General safety guidance, not a project design or a determination of who pays.

TW24 · How to ensure that bid-winning supply chains actually get used

Richard Patterson and Barry Trebes / NEC · 21 January 2020 · Published guidance

Opening explanation of NEC4 ECC and PSC clause 20.1 and the need to put requirements in Scope.

Limit: Predates 2023. Suggested amendments in the article are not incorporated or reproduced here.

TW25 · NEC3 Supply Contract

NEC · NEC3 catalogue; exact executed edition to be identified · Publisher reference

Description and contents: NEC3 procurement of goods and related services, including design.

Limit: Catalogue only; identify the actual Goods Information, pricing documents and publication/revision in the signed agreement.

TW26 · NEC3 Term Service Short Contract

NEC · NEC3 catalogue; exact executed edition to be identified · Publisher reference

Description and Contract Forms: Price List, Service Information and Task Order.

Limit: Catalogue only; no operative duty, deadline or entitlement established for a supplied contract.