Winning UHNW Family Law Property Division Lawyers know that excluded property claims are tricky. But things can get even more complicated in a market where real estate or stocks or other assets have declined in value. MacLean Law dealt with one of the first cases where this complex analysis was applied and won millions for their client in a very short relationship. If you think this may apply to you in a big stakes case, you need to call us first before your ex-spouse does.
FIFO or Pro Rata? How British Columbia Courts Now Divide Intermingled Property After Mills v. O’Connor Tel: 604 602 9000
A New Era for Property Division in British Columbia
Our passionate articled student Armaghan Aliabad knows we help UHNW family law clients win the biggest cases.. For many separating spouses, the family home is both the most valuable asset and the most difficult to divide. Matters become even more complicated when one spouse owned the property before the relationship or contributed inherited funds or gifts that qualify as excluded property under British Columbia’s Family Law Act. During a relationship, however, excluded property rarely remains untouched. Mortgages are paid with family income, homes are refinanced, renovations are completed, and property values rise and fall. These events create what courts refer to as “intermingled” property, making it difficult to determine whose money remains in the asset. Following the British Columbia Court of Appeal’s decision in Mills v. O’Connor, 2025 BCCA 34, courts are increasingly moving away from the traditional FIFO (First-In, First-Out) approach in favour of the ex post facto pro rata method. A recent decision of the British Columbia Supreme Court, S.C.B. v A.M.R., 2026 BCSC 1214, demonstrates exactly how this new approach works in practice. Notably, MacLean Law obtained a winning share of family property in the blockbuster short marriage $ 6million plus property award case based n part on the new approach.
UHNW Family Law Property Division Lawyers -Understanding First-In, First-Out FIFO Tel: 604 602 9000
Historically, one approach to tracing excluded property was the First-In, First-Out (FIFO) method. Under this approach, the earliest contribution to an asset, typically a spouse’s excluded property, is treated as the first contribution to be recovered. If a spouse brought significant equity into a home before the relationship, FIFO generally allowed that excluded interest to be repaid before any remaining equity was divided between the parties.
While straightforward, FIFO can produce harsh results where the property has been refinanced or where the available equity is no longer sufficient to repay every contribution. In those situations, the spouse with the excluded property often receives the full value of that interest, while the reduction in equity is effectively borne entirely by the family property portion. This outcome can substantially reduce the amount ultimately shared between the spouses.
UHNW Family Law Property Division Lawyers- The Ex Post Facto Pro Rata Approach Tel: 604 602 9000
The Court of Appeal in Mills preferred a different method: the ex post facto pro rata approach. Rather than assuming that excluded property survives intact, this method examines all of the contributions made to the asset over time and determines each contributor’s proportionate interest. Those percentages are then applied to the remaining proceeds after the property is sold and debts are discharged.
The reasoning is simple. Once excluded property and family property become mixed together, there is usually no evidence demonstrating whether later withdrawals, refinancing, or reductions in value affected one category of property more than the other. Rather than relying on an arbitrary assumption that excluded property remained untouched, the pro rata approach allocates both gains and losses proportionately. According to the Court of Appeal, this better reflects the principles of fairness found in the Family Law Act.
UHNW Family Law Property Division Lawyers – How the Court Applied These Principles Tel: 604 602 9000
In this case, the respondent entered the relationship already owning the family home and therefore claimed a significant excluded property interest. During the relationship, however, the parties refinanced the property several times, used family income to make mortgage payments, completed renovations, and increased the home’s overall value. The claimant also contributed $40,500 of gifted funds toward the mortgage, which the court accepted as her own excluded property contribution. By the time the parties separated, the remaining equity in the property was insufficient to fully reimburse every excluded and family contribution if the FIFO approach were adopted.
The respondent argued that because he owned the home before the relationship, his excluded property should be repaid in priority using FIFO. The claimant argued that the principles established in Mills required the court to use the ex post facto pro rata approach instead.
Why FIFO Was Rejected Tel: 604 602 9000
The BC Supreme Court concluded that FIFO should not be applied. Although the property itself had never been sold during the relationship, its equity had changed dramatically through refinancing, mortgage payments, renovations, market appreciation, and additional contributions from both parties. The judge held that once those interests became intermingled, it was impossible to determine whether reductions in available equity should be attributed to excluded property, family property, or both.
Following Mills, the court found that giving excluded property automatic priority would simply assume, without evidence, that every reduction in equity came from the family property portion. That assumption was arbitrary. Instead, the reduction in value should be shared proportionately among all contributors.
UHNW Family Law Property Division Lawyers- The Formula Adopted by the Court Tel: 604 602 9000
Rather than simply declaring that the pro rata method applied, the court established a practical formula for dividing the proceeds of sale. First, the gross sale price would be reduced by the outstanding mortgage and the costs of sale, leaving the divisible proceeds. Next, the court would identify each party’s excluded property contributions together with the increase in the home’s value during the relationship. Those amounts would then be used to calculate each party’s proportion of the total contributions. Finally, those percentages would be applied to the divisible proceeds, with the remaining balance divided equally as family property.
The judgment even provides a worked numerical example illustrating how these calculations would operate once the home is sold, making it one of the clearest judicial explanations of the ex post facto pro rata method to date.
[92] For example, if the family home sells for slightly below the list price, $1,700,000, the realtor fees, etc., are $60,000 and the mortgage to be retired is $512,000, the calculation is as follows:
- a) The gross sale price $1,700,000.
- b) The Divisible Proceeds are $1,700,000-$60,000-$512,000=$1,128,000.
- c) The contributions are:
- A.M.R.’s pre-relationship excluded property of $717,389.16.
- S.C.B.’s excluded property contribution of $40,500.
iii. The market increase contribution is $1,700,000 – $900,000 (price of home when married) = $800,000.
- d) The total contributions are $1,557,894.16.
- e) The A.M.R. ratio is 46%.
- f) The S.C.B. ratio is 2.6%.
- g) A.M.R. is allocated $518,880 for his excluded property interest.
- h) S.C.B. is allocated $29,324.20 for her excluded property interest.
- i) $579,795.20 is allocated equally, $289,897.90 to S.C.B. and the same amount to A.M.R.
UHNW Family Law Property Division Lawyers-What This Means for Separating FLA Couples Tel: 604 602 9000
This decision is important because it demonstrates that tracing excluded property is no longer simply a question of determining who contributed first. Where excluded property has become intermingled with family property and there is insufficient equity to satisfy every contribution, British Columbia courts are increasingly favouring proportionate allocation over FIFO. The case also serves as a reminder that the spouse claiming excluded property bears the burden of proving and tracing that interest, and that careful financial records remain essential throughout a relationship.
As refinancing, home equity lines of credit, renovations, and inherited funds become increasingly common, disputes over excluded property are likely to continue. This decision provides valuable guidance for lawyers and separating spouses alike, illustrating how the courts will strive to balance the principle that individuals should retain their excluded property with the equally important principle that spouses should share the wealth accumulated during their relationship in a fair and rational manner.
