Selling an apartment building co-ownership share: rent income, management and partition risk

Selling a co-ownership share in a rented Austrian apartment building is not the same as selling a specific flat or floor. The buyer acquires an ideal share in the entire property. The buyer will therefore review rent income, use arrangements, management, encumbrances and the possibility that another co-owner may later seek to end the co-ownership.

The sale needs a precise allocation: what exactly is transferred, how are income and expenses allocated, who may make management decisions and what happens if a co-owner later seeks partition? Sections 829 to 835 ABGB provide the legal framework.

An ideal share is not the same as a specific sale subject

In ordinary co-ownership each co-owner holds an ideal fraction of the entire property. The share therefore does not automatically identify a particular flat, tenancy or garden. Long-standing use may matter in negotiations. It does not replace a review of the land register and the agreements between the co-owners.

The purchase contract should describe the transferred share by reference to the land register. The data room should also contain use agreements, allocation plans, ancillary areas and rules on costs. A marketing description such as first-floor flat can otherwise create an expectation that is not reflected in the legal subject matter.

The apartment building sale topic page provides the broader contract context. A later creation of condominium ownership is a different transaction from the sale of an ideal share.

Disclose rent income, expenses and the share accounting

A buyer of a co-ownership share will want to know which income is actually attributable to the share. An annual figure in a sales presentation is not enough. Lease agreements, amendments, the rent roll, payment records, deposits, service charges, arrears and open proceedings should be reconciled.

The allocation may follow an agreement between the co-owners or an established management practice. These are not automatically equally reliable. The seller should disclose whether rent is paid into a joint account, who prepares statements and how vacancies, repairs and later adjustments are handled.

The rent roll and tenancy topic page explains the supporting records. For a share sale it is also necessary to state whether the buyer participates directly in the accounting from the cut-off date or whether a separate internal statement continues.

Set out management and use arrangements between co-owners

Sections 833 to 835 ABGB distinguish between different types of management and disposition. The sale process should therefore show which measures were jointly approved and which decisions were made by individual co-owners. Otherwise the buyer may acquire not only a share but also an unresolved decision-making structure.

Important records include bank mandates, management agreements, resolutions on renovation, insurance, maintenance and communications with tenants. Mixed use also requires a description of access, commercial premises, courtyards, roof areas and shared installations. House rules do not answer every question about cost allocation.

The property management topic page is useful for the management perspective. It does not replace a review of ordinary co-ownership, because ordinary co-ownership does not automatically have a condominium organisation.

Check the land register, encumbrances and authority to dispose

The seller should obtain a current land register extract before marketing the share. Review the ownership fraction, mortgages, easements, prohibitions on sale or encumbrance, priority notices and other annotations. The buyer will also need to know whether an encumbrance affects the whole property or only a share.

Obligations can also exist outside the land register. Examples include renovation agreements, loans, guarantees, ongoing litigation and commitments to tenants. These points do not necessarily prevent a transaction. Their legal and economic scope must be disclosed in a way the buyer can assess.

The specialist portal liegenschaftskaufvertrag.at provides further guidance on purchase contract review. For an apartment building share the rent income, management duties and co-owner decisions must be added to that review.

Partition under section 830 ABGB is a separate sale risk

Section 830 ABGB generally gives each participant a claim to end the co-ownership. The claim is contractual in nature and normally does not require a special explanation based on the claimant's personal interests. A buyer therefore acquires not only current income but also exposure to a later partition claim by another co-owner.

In 5 Ob 129/25v of 12 March 2026 the Supreme Court confirmed that line. The opposing party must assert and prove obstacles such as an untimely partition or a disadvantage to the other participants. Such an obstacle generally has to be temporary and capable of falling away or being remedied soon. A permanent disadvantage that necessarily accompanies the end of co-ownership does not automatically prevent partition.

The partition risk cannot be removed by an imprecise clause. Assess whether a physical division is realistic, whether a civil partition may result, whether encumbrances reduce value and whether the co-owners have a workable negotiation path. These questions belong in the seller information and in the discussion of price and security.

Match representations and security to the actual risk

The purchase contract should describe the land register share, known use arrangements and the allocation of rent income. Information on tenancies, arrears, deposits, management records, proceedings and encumbrances should be linked to supporting documents. Sellers should only represent facts that their records can support.

Depending on the issue, suitable solutions may include disclosure, a limited representation, delivery of missing records, an indemnity, escrow or a retention from the price. The appropriate solution depends on whether the issue concerns the sale subject, income, management or a later dispute between co-owners.

The cut-off date and handover must state who collects rent, pays expenses, supplies records and cooperates in proceedings from which date. The handover and cut-off topic page explains this interface. An ideal share also needs a list of rights and duties that cannot be tied to one flat.

Seller checklist for an apartment building co-ownership share

Before marketing, compare the land register share with the actual use. Then assemble the use agreement, rent roll, lease agreements, payment records, deposits, service charges, arrears, resolutions, management agreement, insurance and open proceedings in one organised file.

Every recurring income needs a clear rule: who receives it, who pays the related expense and how is the cut-off statement prepared? Every open legal issue needs a status and a responsible person. This allows the buyer to value the share without filling document gaps with assumptions.

The apartment building risk check can help organise the document status and time pressure before a consultation. It does not replace a purchase contract review or an assessment of the specific partition risk.

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