E6 — ABI Subsidence Agreements Change of Insurer + Tree Root Third-Party Liability

The two voluntary ABI agreements that govern most domestic subsidence claims handling — including the 8-week / 1-year decision matrix.

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EXPERT Subsidence · Further Knowledge · E6 of 6

Important: voluntary status

Both ABI agreements are voluntary under Competition Law Compliance — adoption at each member's discretion. They are not statute. But they are widely followed.

1. Domestic Subsidence "Change of Insurer" Agreement

Introduced 1 January 2000. Applies when:

Date of Notification (from current insurer's policy inception)Outcome
≤ 8 weeksPrevious insurer handles entire claim
No contribution from current
> 8 weeks but < 1 yearInsurer notified handles
Cost split 50:50 between previous + current
Handling insurer keeps the other informed of material developments + reserve
Contributions paid within 21 days with full docs (apportioned VAT invoices)
No interim contributions < £5,000
≥ 1 yearCurrent insurer handles entire claim
No contribution from previous

2. Domestic Subsidence Tree Root Claims Agreement — Third-Party Liability

Introduced 1 October 1997. For subsidence damage caused wholly or partly by tree root encroachment from a domestic owner/tenant/occupier:

  1. Buildings/contents insurer of the damaged property handles + meets the claim per their own policy cover
  2. Insurer of the responsible domestic property is NOT pursued for recovery, regardless of attribution share
  3. Exception — if damage recurs because no reasonable preventative measures were taken by the liable party, the agreement does NOT apply to subsequent claims
  4. No bearing on uninsured loss claims pursued by the insured against the liable domestic party (e.g. for excess, distress, inconvenience)
⚠️ When to read the full wording

Both agreements are short and updated periodically. Always refer to the current ABI wording before relying on them in a dispute.

Decision flow for handlers

  1. Has there been a change of insurer? If no, skip Agreement 1.
  2. What's the date-of-notification interval from the new insurer's inception?
  3. Apply the matrix above for handling responsibility and contribution.
  4. Is there a domestic third-party tree implicated? If yes, Agreement 2 closes off recovery against that domestic insurer (subject to the four points above).
  5. Always check uninsured loss cover for the PH separately.

Source: Subsidence Handbook 4th Edition, Chapter 13 — ABI Subsidence Agreements.

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