In 2026, developer liability does not end at completion — it often starts there.
Many London developers still model risk as if completion marks a clean commercial exit.
Under the Building Safety Act regime, that assumption is increasingly wrong.
Post-completion liability is expanding in scope, duration and visibility — and much of it is not being priced correctly.
The combined effect of the Building Safety Regulator (BSR), the Single Construction Regulator (SCR),
and extended limitation periods means that developers remain exposed long after practical completion,
even where assets have been sold or occupied.
This exposure is now most visible at
Gateway 3 and occupation,
where unresolved risk is crystallised into regulatory record — not forgotten.
1. Why completion no longer caps developer risk
Historically, developers relied on three assumptions:
- Risk transfers to contractors and designers at completion.
- Defects liability periods are short and manageable.
- Insurance responds if something goes wrong.
In 2026 London HRBs, all three assumptions are weakening.
Regulatory enforcement, clearer dutyholder attribution and longer look-back periods
mean that liability increasingly follows who commissioned and controlled the project.
Where Gateway commitments were made by or on behalf of the developer,
those commitments remain relevant long after handover, as explored in
Completion Certificates and Gateway 3: Where London Projects Are Failing.
2. The liability categories developers are underpricing
Regulatory breach exposure
Regulatory non-compliance is not a traditional “defect”.
It can trigger enforcement, remediation and reputational damage regardless of fault allocation.
This exposure is amplified where the Golden Thread is weak,
linking directly to
operational readiness and Golden Thread usability.
Product and system liability
Developers are increasingly exposed where products or systems were approved,
value-engineered or substituted during delivery.
Liability does not disappear with novation or sale.
This connects directly to
how the SCR reshapes product liability,
where responsibility follows approval and control.
Fire and façade exposure
Façade systems remain one of the largest unpriced risks on London HRBs.
Where the installed system cannot be unequivocally proven to match the approved design,
developers retain exposure even after disposal.
This is explored in depth in
Façade Strategy, Fire Performance and Liability Exposure in London HRBs.
Legacy structure uncertainty
Refurbishment and change-of-use schemes frequently carry residual structural uncertainty.
If investigation was limited or assumptions undocumented,
that uncertainty often resurfaces post-completion.
This links directly to
structural investigation expectations for legacy concrete frames.
3. Why insurance is not solving the problem
Many developers assume insurance will absorb post-completion risk.
In practice, insurers are narrowing cover, increasing exclusions and pricing conservatively.
As explained in
Insurance, Indemnity and Uninsurable Risk on London HRBs in 2026,
poorly controlled regulatory and product risks are increasingly uninsurable.
Where risk cannot be insured, it sits with the party best able to influence outcomes —
often the developer.
4. Gateway 3 as a permanent liability record
Gateway 3 approval (or refusal) creates a durable regulatory record.
Conditions, caveats and unresolved issues do not disappear after occupation.
This is particularly relevant where early or phased occupation was pursued.
As detailed in
Early Occupation Risk: When the BSR Will Refuse Partial Approval,
residual risk accepted at occupation can re-emerge later.
5. What developers should be pricing instead
Developers who are recalibrating successfully are now pricing:
- Enhanced investigation and verification during delivery.
- Stronger construction control and change governance.
- Golden Thread systems designed for long-term operation.
- Residual regulatory and remediation contingencies.
These measures reduce long-tail exposure and improve insurability —
but only if embedded early, not retrofitted at completion.
Key takeaway
In 2026 London HRBs, developer liability is no longer capped by completion or disposal.
Regulatory traceability, product scrutiny and evidence-led enforcement
mean that underpriced post-completion risk can reappear years later.
Developers who treat Gateway compliance, control and verification as commercial risk management —
not regulatory overhead — are the ones pricing reality correctly.
image: constructionmagazine.uk
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Expert Verification & Authorship:
Mihai Chelmus
Founder, London Construction Magazine | Construction Testing & Investigation Specialist |
