Short answer. It depends which is worth more. If the cost of the improvement plus the resulting increase in value exceeds the value of the land at the time of the improvement, the whole property goes to the partnership; otherwise you keep it. Either way the other side is reimbursed.
What the law says
When the cost of the improvement made by the conjugal partnership and any resulting increase in value are more than the value of the property at the time of the improvement, the entire property of one of the spouses shall belong to the conjugal partnership, subject to reimbursement of the value of the property of the owner-spouse at the time of the improvement; otherwise, said property shall be retained in ownership by the owner-spouse, likewise subject to reimbursement of the cost of the improvement.
Family Code, Article 120 — Improvements on Exclusive Property (Reverse Accession). Read the full provision →
The building follows the land, until it outgrows it
The ordinary rule of accession is that whatever is built on land belongs to the owner of the land. This article reverses it in one situation, which is why it is sometimes called reverse accession. Where the partnership's contribution is worth more than the land it was spent on, the tail is no longer wagging the dog and the whole property — land and house together — goes to the partnership. Where it is not, the land keeps its owner and takes the house with it. Nothing is ever split into a house owned by one side and a lot owned by the other.
The comparison and the date it is fixed
Two figures are set against each other. On one side, the cost of the improvement and any resulting increase in value — the article counts both, so an expenditure that raised the property's worth by more than it cost is credited with the difference. On the other, the value of the property at the time of the improvement, not today's value and not what the owner paid for it years earlier. That date is the fulcrum of the whole calculation. A lot that has appreciated sharply since the house was built is still measured as it stood when the building went up.
Ownership vests only on reimbursement
Whichever way the comparison falls, the winner owes the loser. The partnership that takes the property reimburses the value of the land at the time of the improvement; the owner-spouse who keeps it reimburses the cost of the improvement. The article then adds the timing that catches people out: ownership of the entire property shall be vested upon the reimbursement, which shall be made at the time of the liquidation of the conjugal partnership. So the question does not resolve during a functioning marriage. It is answered when the partnership is wound up, and not before.
Value it while the evidence exists
Because the numbers are pinned to a past date, the record made at the time is worth more than any later opinion. Keep the construction contract and its cost breakdown, the receipts for materials and labour, the building permit, and any appraisal or tax declaration reflecting the lot's value before the work began. Keep also the proof that the land was yours before the marriage. Where none of that survives, the comparison becomes an argument between competing valuations of a property as it stood many years ago, which is the expensive way to answer this question.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Josefa Bautista Ferrer vs. Sps. Manuel M. Ferrer & Virginia Ferrer, et al, G.R. No. 166496, November 29, 2006 — read the decision on LawPhil →
- Francisco Muñoz, Jr. vs. Erlinda Ramirez, et al, G.R. No. 156125, August 25, 2010 — read the decision on LawPhil →