Novation and the Employer's Requirements
A Hong Kong developer procures a 22-storey Grade A office building through design-and-build. Your firm prepared the concept design under a separate appointment and was then novated to the main contractor. The Employer's Requirements state that the curtain wall must achieve U ≤ 1.8 W/m²K and airborne sound insulation DnT,w ≥ 35 dB. They also attach a typical floor plan showing a 1.5 m raised floor, while the narrative schedule states 600 mm. The contractor tendered a unitised system at U = 2.1 W/m²K and 32 dB, tested to a different standard, and priced the 600 mm raised floor. The contractor now asks your firm to confirm in writing that the substituted systems are 'equivalent and fit for purpose'. Separately, the developer asks the firm to confirm compliance with the Employer's Requirements at handover.
1. How should the conflict between the performance requirements and the drawings, and the raised-floor discrepancy, be resolved? Who bears the risk?
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Resolve it through the contract's priority of documents clause before considering fairness. Design-and-build forms almost always provide that the Employer's Requirements prevail over the contractor's proposals, and that within the Employer's Requirements the specification and schedules prevail over drawings unless the contrary is stated, with figured dimensions prevailing over scaled ones. On that basis:
Curtain wall: U ≤ 1.8 and DnT,w ≥ 35 dB are performance requirements. The contractor bears the risk of meeting them, and 2.1 W/m²K and 32 dB do not meet them. Tested to a different standard is not an answer unless the Employer's Requirements permit that standard or a demonstrated equivalence; a lower tested figure that does not satisfy the specified criterion is simply non-compliant.
Raised floor: here the documents genuinely conflict - 1.5 m on the plan, 600 mm in the schedule. The priority clause points to the schedule, but the plan is a dimensioned drawing and 1.5 m may be the design intent for a Grade A office. Look for any express statement of intent, the employer's brief, and whether the tender queries raised it. A contractor that priced 600 mm without querying a 900 mm discrepancy has taken a risk, but a court or arbitrator may treat an obvious internal inconsistency as a matter for clarification rather than a risk transferred wholesale.
The architect's role post-novation is to advise the contractor-client, not to arbitrate between the parties. Recommend an immediate written query to the employer seeking a formal instruction or variation, with the cost and programme consequences of each reading, and a documented decision. Do not let the contractor build 600 mm by default and litigate later.
2. The contractor asks for written confirmation that the substituted systems are 'equivalent and fit for purpose'. The developer separately asks for a compliance confirmation. What are the professional and contractual issues, and what should the firm do?
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Both requests place the firm in difficulty, and they pull in opposite directions.
After novation, the firm's client is the contractor. The firm can advise the contractor on design and compliance, but it should not issue a confirmation that the systems satisfy a requirement they plainly do not. A written statement of equivalence would be relied on by the contractor, and potentially by the employer - and if it is wrong it converts a contractor design risk into an architect liability. 'Fit for purpose' is a higher standard than reasonable skill and care; never give it casually, and check whether the novation agreement contains a fitness-for-purpose warranty, which is unusual but not unknown in design-and-build.
The developer's request is a conflict of interest issue. The firm may owe the employer duties under a collateral warranty or the novation agreement, but it cannot act as the employer's independent certifier while being the contractor's designer on the same scope. Check exactly what the novation agreement and any warranty provide: if the firm owes a duty of care to the employer, it must tell both parties that it has received the request, and decline to certify its own client's work. Suggest an independent certifier or the employer's own consultant.
Actions: respond in writing to the contractor, declining to confirm equivalence and advising a compliant design or a formal variation through the correct channel; advise the contractor of the cost consequence and of the risk under the design warranty; reply to the developer identifying the conflict and proposing an independent route; notify the professional indemnity insurer if a claim is foreseeable; and keep the novation file and the original concept design records separate, with confidentiality respected.
3. If the raised-floor discrepancy turns out to have a building-height consequence, what should the architect do, and what are the approval implications?
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Quantify the consequence first. An extra 900 mm over 22 floors adds roughly 19.8 m to the overall height if the floor-to-floor dimension is unchanged - which may breach the height restriction in the lease, the Outline Zoning Plan or the approved plans, and may affect the plot ratio and site coverage calculations if the raised floor is counted.
If the discrepancy cannot be absorbed, the options are to redesign, to seek a variation with a reduced floor-to-floor dimension, or to confirm 600 mm and accept a lower specification. Each has cost and programme implications that belong in a written instruction, not in a corridor conversation.
Statutorily, check what has already been submitted to the Buildings Department. If plans have been approved on the basis of a stated overall height and a stated raised floor, changing to 1.5 m requires amended plans and fresh approval and consent before the works proceed; building to a different height from the approved plans is unauthorised. If the lease or planning permission caps the height, exceeding it is a separate problem that may require a lease modification or planning application, with a much longer lead time than any site saving.
The architect should issue a formal design query, obtain the employer's written instruction, record the decision and its basis, update the risk register, and advise the contractor not to order raised-floor components or set out the floor-to-floor heights until the decision is confirmed. Also check whether the structural design, the lifts, the façade module and the staircase geometry all assumed the same dimension - a 900 mm change rarely travels alone.