How to Use the Product Substitution & Compliance Approval Form (Controlled Change)

Purpose and outcome (what it’s for)

This form controls product/system substitutions so the right thing gets built and you can prove it later. Use it when a subcontractor or supplier wants to swap what’s specified on the drawings/spec.

Good completion looks like: the proposed substitute is clearly described, the required performance is checked, Building Regulations/design impacts are considered, the right people sign off before ordering/installation, and all supporting evidence is filed.

Rule on site: No approval = no order = no install.

Who uses it (roles and responsibilities)

When to use it (timing and triggers)

• Use it as soon as the need is identified (lead time issues, discontinued products, design coordination clashes, value engineering, etc.).
• Always before: ordering, off-site manufacture, delivery booking, installation, or covering-up works.
• Use it for: any change to specified products/systems, including “same but different” (model change, thickness, fixing pattern, fire rating, membrane type, insulation grade, door set, glazing, M&E components, etc.).
• Don’t use it for: like-for-like replacements with identical model/spec and no compliance impact (still record the batch/traceability where needed).

Before you start (information and evidence you need)

Chase the basics first. Most substitutions fail because the evidence is missing or doesn’t match the exact build-up.

Minimum inputs

• Original requirement: the drawing/spec reference, detail reference, schedule item, or employer standard that the product comes from.
• Exact proposed product: manufacturer, model, size/finish, full system components (not just “equivalent”).
• Location and use: plot/level/room/area, and what the product is doing there (fire barrier, external weathering, acoustic separation, etc.).
• Installation method: fixings, adhesives, membranes, seals, fire stopping, interfaces with other trades.

Evidence pack (attach what applies)

• Datasheet and installation instructions (current revision).
• Declaration of Performance (DoP) and UKCA/CE info (as applicable).
• Test reports and/or 3rd-party certification relevant to the use (fire, acoustic, structural, thermal, weathering).
• System drawings/build-up details (showing the whole assembly, not just a single component).
• Compatibility confirmation for interfaces (e.g., membrane-to-tape, insulation-to-render system, fire stopping to substrate).
• Warranty statement and any conditions that affect the project.

HRB projects: confirm HRB status early. If it is an HRB, you also need the change classification (Recordable/Notifiable/Major) and any required BSR step before implementation.

How to complete it (step-by-step)

1. Raise the request (Section 1)
   • Fill in project details, location (plot/level/area), and a unique substitution reference.
   • Make sure the requester’s contact details are included so queries don’t stall the job.
2. Describe exactly what is changing (Section 2)
   • Write the specified product/system and the proposed substitute in full (manufacturer + model + spec).
   • State where the original is referenced (drawing/spec/rev). If you can’t point to the requirement, you can’t prove compliance.
   • In “what exactly is changing”, be specific: thickness, rating, component list, fixing centres, substrate prep, sealants, membranes, etc.
3. Give the real reason (Section 3)
   • Tick the reason and write a short site-friendly explanation (e.g., “12-week lead time would delay handover” or “original discontinued”).
   • If it’s cost saving, state whether it changes performance, warranty, maintenance, or appearance. If yes, expect deeper review.
4. Check performance requirements (Section 4)
   • Copy the required performance from the spec/design for that location (don’t guess).
   • For each line, state “Yes/No/NA” and add a short note pointing to the evidence (e.g., “Yes – Test report TR-104 rev B”).
   • If any item is “No” or “Unsure”, stop and escalate to design/technical review.
5. Assess Building Regulations and design impacts (Section 5)
   • Tick any Parts that might be affected. If you’re unsure, tick it and get it checked.
   • Think about knock-ons: fire stopping details, moisture layers, acoustic junctions, structural fixings, ventilation rates, insulation continuity, accessibility clearances.
   • Record what must be updated (drawings, details, schedules, calculations, O&M info).
6. HRB change control (Section 5A, if applicable)
   • Confirm HRB status. If HRB = Yes, classify the change: Recordable / Notifiable / Major.
   • Record the reason for the category in plain English.
   • If Notifiable/Major, record the BSR submission/reference and outcome. Do not implement until the required step is complete.
7. Attach the evidence list (Section 6)
   • List each document with filename/reference, date, and revision.
   • Make sure evidence matches the exact product and intended use (not a “similar product” brochure).
8. Record programme and cost impact (Section 7)
   • Note lead times and any abortive works risk (e.g., already installed substrates, prefabrication, deliveries booked).
   • If there’s a cost change, ensure it aligns with the contract/commercial route (don’t mix approval with valuation).
9. Get the right approvals (Section 8)
   • Tick who is required. As a minimum, include PM/Site and Design review for anything that touches compliance or interfaces.
   • Do not treat “Approved with Conditions” as a green light until conditions are met (e.g., “only if installed with X fixing” or “only for non-HRB areas”).
   • Set the latest date to order once approved to prevent last-minute site pressure.
10. Communicate and close out (Section 9)
    • Brief supervisors and label the old spec “DO NOT USE”.
    • Set a delivery check: confirm the label/model delivered matches the approved substitute.
    • After install, file photos, QA checks, certificates, delivery notes, and as-built updates.

Review and approval (what “good” looks like)

Approvers should check these points before signing:

• Clarity: Can someone independent identify exactly what will be installed and where?
• Performance: Does the evidence demonstrate it meets the specified requirements for that location?
• Whole system: Are interfaces and associated components included (fixings, membranes, fire stopping, sealants)?
• Compliance: Any Building Regs impacts identified and addressed (and HRB change control followed where applicable)?
• Deliverability: Can site install it correctly with the available skills, tolerances, and sequence?
• Conditions: If approved with conditions, are they clear, measurable, and communicated to site?

Escalation (when to stop and ask)

• Anything affecting fire performance (materials class, fire resistance, cavity barriers, fire doors, cladding, fire stopping).
• Anything affecting structure or primary fixings.
• Anything that changes a tested/certified system build-up (e.g., swapping one component inside a certified façade or partition system).
• Any substitution where evidence is missing, out of date, or not for the same use case.

Recordkeeping (storage, version control, retention)

File the approved form and evidence so it’s easy to find later (snagging, handover, warranty queries, audits, or Building Safety Act expectations).

Where to store

• Project document control system (preferred) under a folder like: Controlled Changes / Product Substitutions.
• If you don’t have a system: a shared drive with one agreed folder structure and a single “index” log.

How to name and link records

• Use the Substitution Ref in the filename (e.g., PS-012_ApprovedForm.pdf).
• Save evidence files with the same ref prefix (e.g., PS-012_Datasheet_revC.pdf).
• Link to related records: RFI, design change, drawing revision, site instruction, NCR, inspection/QA record.

Retention

Keep substitution approvals and evidence for the project record period your contract/client requires. For higher-risk work and safety-critical systems, keep it for the period you need to support handover, warranty, and any statutory obligations. If in doubt, keep it with the as-built/handover set.

How often it should be reviewed or updated

• Each substitution: review once more when the product is delivered (label/model check) and when installed (photo/QA evidence).
• If approvals are “with conditions”: update/append evidence once conditions are met (e.g., revised fixing detail issued).
• If the proposal changes: raise a new substitution reference or formally revise the request (don’t overwrite history).
• Regular site control: weekly look-ahead review of any pending substitutions to prevent last-minute pressure installs.

Common mistakes and how to avoid them

Worked scenario (what this looks like on a real job)

Situation: Drylining subcontractor can’t get the specified acoustic insulation due to a 10-week lead time. They propose an alternative brand available in 2 weeks.

• Step 1: Subcontractor raises the form with a substitution ref and states the exact plots/levels affected.
• Step 2: They list original vs proposed product with full model, thickness, density, and installation method.
• Step 3: In performance requirements, they copy the acoustic and fire requirements from the spec and attach the relevant test reports for the proposed product (and confirm it’s suitable in the same partition build-up).
• Step 4: Design Manager checks if the acoustic test evidence applies to the same wall type and identifies any drawing/spec update needed.
• Step 5: PM records programme benefit and confirms any cost impact route separately.
• Step 6: Site Manager briefs the team, sets a delivery check to confirm thickness/density on labels, and files install photos and QA checks at close-out.