Five factors affecting rebuild cost accuracy this year

In 2026, rebuild cost accuracy is under pressure from five key areas: labour capacity, regulatory standards, material price variation, property complexity and the age of the valuation. It is no longer enough for a sum insured to look plausible. It also needs to be supported by evidence that reflects current reinstatement conditions.

“Rebuild cost accuracy is about more than the price of materials,” said Gautham Rajendar, Technical Lead at RebuildCostASSESSMENT.com. “It’s a combination of data quality, regulation, and construction dynamics — all moving at once.”

For insurance purposes, the building sum insured should reflect the full cost of reinstating the property, not its market value. That figure should account for items such as materials, labour, professional fees, demolition and debris removal, and any applicable non-recoverable VAT.

Five factors are especially important when reviewing rebuild cost accuracy this year:

1. Labour Market Conditions

Labour remains a major source of rebuild cost variability. Official labour-market and skills evidence continues to point to recruitment and retention pressures across construction. Regional differences in labour availability can also affect contractor pricing and reinstatement timelines, which is why local cost data matters when setting buildings sums insured.

What to check: Have local contractor availability, wage pressure or regional labour constraints changed since the last rebuild cost assessment?2. Regulatory Compliance

The Building Safety Act, along with updated fire safety and energy regulations, can add time and cost to certain reinstatement projects. Higher-risk building rules, fire-safety duties and energy-efficiency standards may all need to be reflected in a current rebuild cost assessment, particularly where an older valuation predates recent regulatory change.

What to check: Could higher-risk building rules, fire-safety duties, energy-efficiency standards or other regulatory changes affect the current reinstatement cost?3. Supply

Chain and Material Costs 

Material-price inflation has eased from the sharpest post-pandemic peaks, but category-level movement still matters. The latest Department for Business and Trade materials data showed the ‘All Work’ materials price index up 2.1% in February 2026 compared with February 2025, with some products rising faster and others falling. A rebuild cost assessment should therefore look beyond headline inflation and consider the materials actually required for the property.

What to check: Review whether the property relies on materials or components that have moved differently from headline construction inflation.

4. Property Complexity

Commercial and mixed-use buildings can be especially exposed. Reinstatement may involve plant, mechanical and electrical services, fire-protection systems, tenant improvements, specialist fit-outs, lifts, access constraints and compliance upgrades. If these features are not captured, a simplified estimate can materially understate the true rebuild cost.

What to check: Is a desktop assessment sufficient, or does the property’s complexity call for a more detailed site-based review?

5. Frequency of Review

Even the most accurate valuation loses relevance over time. Inflation adjustments help, but if the base figure is outdated, errors can compound. As a general guide, a full Rebuild Cost Assessment should be reviewed every three years, with costs updated each year for inflation. More frequent reassessment may be needed where the property has been altered, refurbished, extended, changed in use, or affected by unusual local cost pressures.

Practical takeaway: Check the date and basis of the last RCA, rather than relying on indexation alone.

Why indexation alone is not enough for rebuild cost

For brokers, valuation accuracy is now an important part of the advice and evidence trail. A current RCA can help support renewal discussions, demonstrate how the building's sum insured was reached, and reduce reliance on historic figures or indexation alone.

For property owners, the practical question is simple: has anything changed since the last assessment? Extensions, refurbishments, energy-efficiency upgrades, new plant, changes of use, major repairs, or reliance on index-linking alone can all move the current reinstatement cost away from the figure on the policy.

“The market is asking for better evidence behind sums insured,” Gautham added. “A professional RCA gives brokers, owners and insurers a clearer basis for discussing whether cover reflects current reinstatement conditions.”

Rebuild cost accuracy is becoming a more visible measure of insurance quality. Understanding these five influences gives brokers and property owners a clearer basis for reviewing sums insured, questioning outdated figures and keeping cover aligned with current reinstatement conditions.