Short answer

If you and your sibling co-own a house in California and you cannot agree on keeping or dividing it, you can ask a California superior court to force a partition. A court can order the property divided (partition in kind) or, more commonly for houses, ordered sold and the net sale proceeds divided among the owners. To start, you normally file a complaint for partition in the superior court where the property sits. The process can be complex, so prepare for court steps, potential delays, and costs. See the California Code of Civil Procedure chapter on partition for the governing rules: Code of Civil Procedure, Partition.

Detailed answer — what to expect and the steps to force a partition sale

1. Confirm who actually owns the property

Look at the recorded deed. Common forms of ownership are joint tenancy, tenancy in common, and ownership by an estate or trust. If title shows you and your sibling as tenants in common (most common after an inheritance), each co-owner has a divisible share that can be partitioned. If title shows joint tenancy with right of survivorship, ownership may have changed automatically at your father’s death. If the property is still in your father’s name, check whether probate has been opened and whether the court or personal representative has distributed the property. You generally cannot force partition against property that is not yet owned by the heirs.

2. Try to resolve the matter without court

Courts prefer owners try negotiation first. Options include:

• One owner buys out the other’s share at an agreed price.
• Sell on the open market by mutual agreement and split proceeds.
• Use mediation to reach a compromise on sale, timing, or buyout terms.

These routes save fees, time, and uncertainty.

3. File a partition action in superior court if negotiation fails

When negotiation fails, the typical next step is a complaint for partition in the superior court for the county where the property is located. Basic elements:

• The complaint names all parties with an ownership or recorded interest (co‑owners, mortgage holders, lienholders, and anyone with a recorded claim).
• The complaint includes a legal description of the property (from the deed) and asks the court to divide or sell the property and distribute proceeds.
• All parties must be served with the complaint and given notice.

4. Court decision: partition in kind or sale

The court will consider whether partition in kind (dividing the land) is practical and equitable. For a single-family house on one lot, physical division usually is impractical. In practice, the court often orders a sale and directs how to handle the sale procedure and distribution of proceeds.

5. Sale process, referee or commissioner, and distribution

If the court orders sale, it often appoints a referee or a court officer to carry out the sale. The referee arranges listing and sale, handles bids, and transfers the property. Out of the sale proceeds the referee will typically pay:

• Mortgage and other superior liens.
• Costs of sale, unpaid property taxes, necessary repairs and maintenance attributable to preparing the property for sale.
• Costs of the partition action (court costs, referee fees) and sometimes attorney fees if the court awards them later.

After those payments, the referee distributes the remainder to co‑owners according to their ownership shares, adjusted by court-ordered credits or offsets (for example, if one co-owner paid most mortgage payments or made valuable improvements).

6. Timing and costs

Partition actions can take several months to over a year depending on complexity, whether title issues exist, and court schedules. Expect filing fees, service costs, referee or broker fees, escrow expenses, and likely attorney fees if you hire counsel. The court can consider awarding fees in certain circumstances but does not automatically cover everyone’s attorney costs.

7. Common complications

• If the property is in probate or held by a trustee, the personal representative or trustee may have duties or authority that affect timing or the ability to partition.
• Recorded liens or mortgages must be paid or handled in the sale.
• Claims that one co-owner caused waste or prevented sale may affect equitable distributions.
• If one co-owner is entitled to a statutory or homestead exemption, that may affect net proceeds.

8. Documents and evidence to gather

Before you file, collect:

• Recorded deed(s) and legal description.
• Death certificate and any relevant probate documents.
• Mortgage statements, tax bills, home insurance, HOA documents (if applicable).
• Receipts for payments you or your sibling made that you may ask the court to credit you for (mortgage, repairs, property taxes).

9. Where to file and basic forms

File the partition complaint in the superior court for the county where the property sits. Each county court has local rules and filing procedures. If you plan to represent yourself, contact the court’s clerk or self-help center for guidance on filing forms and service requirements. For statutes that govern partition in California, see the Code of Civil Procedure, Partition chapter: https://leginfo.legislature.ca.gov/faces/codes_displayText.xhtml?lawCode=CCP&division=3.&title=&part=3.&chapter=2.

Helpful hints

• Start by confirming title: a certified copy of the deed from the county recorder will show current ownership and any liens.
• Open communication: a neutral mediator can save time and money and preserve family relationships.
• Get a preliminary title report before negotiating a buyout or sale; it shows liens you must address.
• If you need proceeds quickly, consider offering the sibling a buyout financed by a bank or a private loan to avoid court costs.
• Keep clear records of money you spend on the property (mortgage, taxes, insurance, repairs); courts may credit those sums to you.
• Ask the court clerk or a self-help center for local filing steps if you intend to proceed without a lawyer.
• Get a short consultation with a California real property attorney to review your options and likely costs. Even one hour can clarify strategy.