In X v Y [2025] EWFC 144 (B), District Judge Stone delivered a forensic and educational judgment on a topic that regularly vexes family lawyers: can a final financial remedy order be reopened or varied simply because the property market dips?

Spoiler alert: the answer is no—at least not on the facts of this case.

Background: A House, a Fixed Sum, and a Change of Heart

The parties had agreed (and the court ordered) that the former matrimonial home in Cornwall would be sold, with the wife (Mrs Y) receiving £410,000 and the husband (Mr X) receiving the balance, after deducting various sale-related costs and a minor costs award.

At the time of the final hearing in December 2023, the property was valued at £800,000 based on a joint expert report. Both parties expected it might sell for more, but the court stuck with the expert figure. Notably, both had opted for fixed sums rather than percentage-based awards—Mr X specifically proposing to take the risk (or gain) if the property sold for less (or more).

When the market softened and the best offer received was £795,000, Mr X brought an application to set aside or vary the order, arguing that the change in property value was a material development rendering the order inequitable. He framed the claim under the Thwaite jurisdiction.

The Legal Framework: Barder and Thwaite

  • Barder v Caluori [1988] AC 20 sets a high bar: to set aside a financial order due to a supervening event, the event must be unforeseen, exceptional, and undermine the basis of the order. It must occur shortly after the order and not prejudice third parties.
  • Thwaite v Thwaite [1982] Fam 1 is a narrower route, applicable only where the order remains executory (i.e. not fully implemented) and it would be inequitable to enforce it due to a significant change of circumstances. Crucially, if parties’ claims have already been dismissed, the court cannot substitute a new order, only refuse enforcement.

Here, Mr X had opted for Thwaite, recognising Barder was doomed to fail.

The Decision: Variation Refused, Order Upheld

DJ Stone dismissed the application. He found:

  • The property’s small reduction in value was not a sufficiently significant change. Mr X stood to lose a maximum of £13,000, and in some scenarios might even benefit due to elapsed mortgage penalties.
  • Mr X had proposed this very model of fixed-sum order—he took the upside risk, and must also accept the downside.
  • There was no suggestion of wrongdoing or delay by Mrs Y.
  • There was no expert evidence that the property’s value had truly dropped—just a single estate agent letter referencing a hesitant buyer.

Most importantly, the judge noted that even if he found the order inequitable, the court lacked jurisdiction to replace it because both parties’ financial claims had been dismissed outright in the original order. The application had nowhere to go.

Key Points for Family Lawyers

  1. Be careful with fixed-sum orders based on property values. If the market shifts, there's no guarantee the court will reopen the deal—particularly where a percentage-based award might have self-adjusted.
  2. Barder remains a high bar—it requires a genuinely unforeseen, devastating event.
  3. Thwaite is alive but limited: It applies only to executory orders and mainly allows courts to refuse enforcement—not rewrite orders—unless claims remain live.
  4. Dismissing claims outright? Double-check that the structure of your order doesn’t box your client out of relief if the sale goes awry.
  5. Market changes are not enough on their own—courts expect parties to accept ordinary risks.

Conclusion

This judgment is a useful clarification of the narrow—and narrowing—routes by which parties can revisit final orders. Mr X gambled on the market and lost slightly, but the court refused to let him reshuffle the deck. For family lawyers, the message is clear: structure settlement orders carefully, and don’t assume market movements will justify a second bite at the cherry.