Specification Change Control from Tender to Completion

What is the difference between a revision, an instruction and a variation?

A revision changes a document, an instruction directs the contractor, and a variation changes the contractual works and usually the sum or time. A specification change often involves all three, and each needs its own record.

Three words are often used as if they meant the same thing. Keeping them apart avoids confusion on site and in the contract.

A specification revision is the document-control record. It tells the next reader what changed. An instruction is the contractual communication that makes the change effective. A variation is the commercial consequence. If a team tracks only one of these, the other two drift: the clause is revised but the contractor never received an instruction, or an instruction is issued with no revision to the specification.

This matters for the specification because an informal change to a clause, agreed in a meeting or by email, may be argued later as a variation or as a mistake in the contractor's price. A written chain from the request to the revised clause, the instruction and the valuation closes that argument.

How should tender queries and addenda be handled?

Log every query, answer in writing, issue changes to all tenderers as a numbered addendum, and revise the specification in step so the contract set matches what was priced.

Before the contract is let, the specification changes through tender queries and the addenda that answer them. The process is simple, but the details matter, because every tenderer must price the same document. A query answered only to the tenderer who asked produces tenders on different bases.

Keep the query log

Record every query and every answer, including those that do not change the documents. Patterns show where the specification is unclear. A cluster of queries on one clause points to missing information, and fixing the clause protects the next project. The log also protects the design team when a contractor later says it asked and nobody replied.

Addenda that change the specification

An addendum should say precisely what has changed. Quote the clause number, show the old and new text, and identify any consequential change on the drawings or schedules. Do not issue an addendum that adds a requirement without checking whether it contradicts another clause. This is the moment when many contradictions are introduced, because the change is made in a hurry and checked against nothing. The defects at contract issue guide shows how often it happens.

Open items at tender

Open TBCs and provisional items at tender cannot be closed by addendum without consequences for price and programme. If a decision is unresolved, say so, say who owns it and when it will be settled. The TBCs at tender guide sets out how to treat them.

How are specification changes handled after the contract is let?

Route every change through the same steps: receive, classify, assess, decide, instruct, revise and record. Define 'or equivalent' in measurable terms, and treat a substitution as a change to be assessed.

After the contract is let, change comes through instructions, requests for information, submittals and client decisions. The specification is the reference for judging each one, which is why its wording on submissions and approvals needs to work before it is needed.

Product substitutions and "or equivalent"

"Or equivalent" is the most common source of unplanned change. If it is not defined, it invites substitutions based on price. Define equivalence in the specification as a list of measurable requirements: the same performance values, the same classification or test evidence, the same warranty, compatibility with adjoining products and the same programme. Name the evidence the contractor must submit with the request and the time allowed for review. State who approves, and say that approval does not relieve the contractor of its obligations.

Treat the substitution as a change request. The reviewer checks it against the requirements, records the decision and issues a revised clause or an instruction if the product changes. Where the product is part of a system with test evidence, a substitution that breaks the tested configuration is not equivalent, however similar the data sheet looks. On a higher-risk building, check the substitution against the approved application as well; the Gateway 2 specification guide shows how substitutions map to the Building Safety Regulator's change tiers.

Approvals and design responsibility

Reviewing a submission is not the same as taking on the design. Keep comments to compliance with the stated requirements, and avoid directing how the contractor should design its portion. The CDP specification guide covers this in more detail.

How do you keep drawings, schedules and the specification in sync when things change?

Give each repeated value one authoritative home, route every change through one register, and issue the revised documents together so the set shows the same position.

Most specification contradictions after contract come from a change that reached one document and not the others. The cure is not more checking at the end. It is an agreed home for each value and a single route for change.

One register, one revision identifier

Use one change register for the project. Each entry lists the documents affected and the revision identifier of each. Issue a package of revised documents together, not one at a time. If the specification, schedules and drawings carry different revision labels, add a note that cross-refers them so a reader can tell which combination is current.

Decide which document holds the value

For each repeated value, choose the authoritative document. For a door fire rating this may be the door schedule, with the drawings and specification referring to it. When it changes, only the schedule is edited and the references stay valid. This is the same principle as the comparison checks in the beginners' guide, applied to change.

• ✓Every change has an entry in the register with a reason and approver.
• ✓Every affected document shows the same revision of the change.
• ✓Superseded versions are kept and marked.
• ✓Issue packages list what has changed since the previous issue.
• ✓Contractor submittals are checked against the current revision.
• ✓Open items from earlier issues are closed or carried forward.

What does change control add on higher-risk buildings, and what is needed at handover?

On higher-risk buildings, changes to the approved documents are regulated and logged, and the log supports the completion application. At handover, the final specification, the change register, test evidence and as-built product information complete the record.

On higher-risk buildings in England, change control is regulated. The documents approved at Gateway 2 become the agreed documents, and changes to them must be managed under the change control plan and recorded in the change control log kept by the principal contractor. The Building Safety Regulator's guidance distinguishes recordable, notifiable and major changes; see the Gateway 2 specification guide and the Gateway 2 submissions guide.

The specification supports the record in three ways. It sets the evidence expected for each element, so the as-built file can be checked against it. It provides the baseline that each change is measured from. And, when kept as a versioned document, it satisfies the golden thread requirement that earlier versions are not lost. See the golden thread guide.

For projects outside the higher-risk regime the same discipline still applies. Clients increasingly ask for as-built information in a structured form, and the Building Regulations require fire safety information to be given to the responsible person at completion in the cases the regulations set out. Check the current requirements for the project. A project that has kept its change register has most of that information to hand.

Questions technical directors ask about specification change control

What is the difference between a revision and a variation?

A revision is a change to a document, recorded in its revision history. A variation is a contractual change to the works, such as an alteration to design, quality or quantity, which usually follows an instruction and affects the contract sum or time. A specification revision can reflect a variation, but a revision does not by itself create one.

How should tender queries and addenda be handled?

Log every query with a reference, answer it in writing, and issue answers that change the documents to all tenderers as a numbered addendum, with revised pages or clauses identified. The specification is revised at the same time so the issued tender set remains consistent. Make the cut-off date for queries and the effect of addenda on the tender date clear in the tender instructions.

What does 'or equivalent' mean in a specification?

It means the contractor may propose an alternative to the named product, provided it meets the stated requirements. The specification should define equivalence in measurable terms, state what evidence the contractor must submit and name who approves. Without that, 'or equivalent' becomes a negotiation after the contract is let.

Who approves a product substitution?

The contract and the specification should say. Usually the contractor submits, the designer reviews against the stated requirements and the contract administrator responds. On higher-risk buildings in England, substitutions may also be recordable, notifiable or major changes under the Building Safety Regulator's guidance.

How do you keep drawings, schedules and the specification in sync during change?

Decide which document holds each value, route every change through one register and check the full set before reissue. A change recorded only in the specification, or only on a drawing, creates the contradictions that appear in most issued documents.

What records are needed at completion?

The final specification as built, the log of changes and substitutions with approvals, submittals and test evidence, and the product and maintenance information for the building's operator. On a higher-risk building, the updated agreed documents and the change control log also support the completion application and the golden thread.

Where Avoice fits

Change control is a record-keeping and comparison task: one route in, one register, and a check that the whole set agrees. That is the work software does well once the practice has set the rules.

Avoice's Construction Admin module covers submittals, RFIs, instructions and specification change tracking, so a request, the decision, the instruction and the revised clause sit in one record. When a clause changes, the pre-issue Technical Review compares the revised specification with the schedules and drawings, which is where changes that reached only one document show up.

On higher-risk buildings, the Compliance module's Project Record logs documents and decisions with their date and author, and the golden thread view and export draw on that record. Practice rules can define what equivalence evidence a substitution request must carry.

Software can log, compare and flag. The decision to approve a substitution or issue an instruction remains with the people who hold that authority under the contract.