Value engineering, an unsealed drawing and a conflict of interest

Technical assessment first

The submission fails on three independent grounds, and the client should see all three:

1. Compliance. The recalculated 9.6 W/m² exceeds the code limit of 9.5 W/m². A code limit is a cap, not a target; the original 8.8 W/m² carried a deliberate margin for installation tolerances and later fit-out changes. Exceeding it is a non-compliance, not a design preference.
2. Visual performance. UGR 22 exceeds the specified UGR < 19 in the cellular offices. The specification was not arbitrary - UGR limits exist because glare in screen-based workplaces is a recognised problem, and 22 in a small cellular office will be noticeable to occupants.
3. Quality and durability. Lower efficacy means higher running energy for the life of the fit-out, which offsets part of the capital saving; CRI 80 versus 90 changes colour rendering; dimming to 10% removes low-level dimming used for the daylight control strategy; the two-year warranty versus five transfers risk to the client; and the absence of ENEC or equivalent third-party certification removes independent evidence of safety and performance.

Process

• Reply to the project manager in writing, copying the client's authorised representative, with a short technical evaluation note. An email from the PM is not a formal instruction to vary the design.
• Request the evidence: LM-79 photometric files, LM-80 and TM-21 data for the LED source, driver datasheet including dimming protocol, CB or ENEC certificates, warranty terms, and the UGR and LPD recalculations from the proposed product's own data.
• Re-run the calculation with the submitted product rather than accepting the contractor's figures.
• If the client still wishes to proceed, treat it as a formal variation instructed by the client, record in writing that the design intent and code compliance are not met, and confirm who is accepting that risk.

Do not approve a non-compliant substitution under programme pressure. That pressure is precisely the circumstance the professional obligation exists for.

Identify the threat

This is a self-review and conflict-of-interest problem. Your firm designed the controls, specified the luminaires and may now be paid by the installing contractor to commission the same system. There is a direct incentive to accept the substitution, to sign off work that is not complete, and to be less than rigorous about defects - because the contractor paying you wants a clean handover and the programme is already under pressure. Even with complete integrity, the appearance of the arrangement undermines the client's confidence in the design advice.

Options

1. Decline the commissioning appointment where the same firm is the designer and the client's adviser. This is the cleanest outcome.
2. Proceed with informed consent and separation. Disclose the arrangement in writing to the client's authorised representative before accepting, obtain written consent, use a different team for commissioning from the design team, and put an independence and reporting protocol in place so that commissioning results are reported to the client, not filtered through the contractor.
3. Third-party certification. If the client needs an independent commissioning certificate, that should come from someone with no contractual relationship with the installing contractor.

What to say

Raise it early, in writing, to both the client and the contractor. State the conflict plainly, state how it will be managed, and let the client decide whether to consent. Silence is the failure mode: an undisclosed arrangement discovered later damages the firm far more than a declined appointment. The professional obligation is to disclose and manage, not to avoid every situation that might be uncomfortable.

Refuse the seal, offer the review

The seal identifies the designer who prepared and takes responsibility for a design. It cannot be lent. Placing your seal on drawings prepared by the contractor to communicate the contractor's alternative would misrepresent who prepared the design, would attach your professional responsibility to content you did not produce or verify, and in most jurisdictions would be a breach of the registration rules - and potentially an offence - regardless of the commercial pressure behind it.

What you can do

1. Review and mark up. Review the contractor's drawings as shop drawings or as a technical submission, and return them marked 'reviewed - not approved for construction', with a clear statement of what was and was not checked. A review comment is not a design endorsement.
2. Keep the design documents yours. If the design genuinely changes, you revise and issue your own drawings, and you seal those - after you have satisfied yourself that the change complies.
3. Separate the document sets. Contractor-produced installation drawings can carry the contractor's own title block and be reviewed by you. The design intent drawings, specifications and calculations carry yours.
4. Record it. Confirm the position in a short letter to the contractor and the client, explaining why the seal cannot be lent and what review service you are providing instead. This also protects the client, who may not realise that a sealed contractor drawing would appear to have designer endorsement behind it.

The request is common in programme pressure and is rarely malicious - contractors often see the designer's title block as a shortcut to acceptance. The answer is still no, delivered quickly and with an alternative, so the programme is not held up by the refusal itself.