Construction Period

Why it matters for underwriting

The construction period defines the time-on-risk for a CAR/EAR policy, which is normally written for a fixed term rather than an annual cycle, so its length directly shapes the exposure the insurer carries. A longer period increases the cumulative probability of a weather event, fire or collapse occurring at some point during the works, and it extends the window during which cash-flow pressure, subcontractor turnover or seasonal effects can degrade site discipline. Underwriters also use the declared period to check that the sum insured, escalation assumptions and reinsurance placement match the actual duration of exposure rather than an optimistic construction schedule.

Capturing the attribute and evidence

Proposal forms ask for the planned start and completion dates, split where relevant into the construction phase, testing/commissioning and any contractually agreed maintenance period. Underwriters verify the declared timeline against the project programme or Gantt chart, the construction contract’s milestone dates, and the validity period stated on the building permit, since permits often expire before informally extended schedules.

Effect on coverage, premium and conditions

Premium is typically quoted for the declared period and prorated or surcharged for extensions, since risk accumulates with time rather than being a flat annual charge. Insurers commonly attach an automatic extension clause allowing a limited grace period at an agreed additional premium, while material overruns beyond that grace period require an underwriting review and can trigger renegotiated conditions or, in extreme delay scenarios, declinature of further cover.

Mitigation measures

Project owners and contractors mitigate construction-period risk by building realistic weather and supply-chain contingency into the programme, notifying insurers early of anticipated delays so an extension can be underwritten proactively, and phasing high-risk activities such as roofing or waterproofing to avoid exposure during peak storm or flood seasons.