Buying an Apartment Building in Switzerland: A Due Diligence Checklist

Buying an apartment building in Switzerland involves more than comparing a price with annual rent. You also take on maintenance decisions, financial uncertainty and day-to-day responsibilities. This practical checklist explains how to review documents, identify unanswered questions and build a sound basis for a decision before making a binding commitment.

1. Define what the investment should achieve

Are you looking for regular income, an asset to hold within the family or a property with development possibilities? These objectives call for different buildings and different financial buffers. A fully let property may suit a different strategy from one requiring extensive work. Before making an offer, write down which responsibilities you intend to handle yourself and which require professional support.

Decide how much money should remain available after completion. The highest purchase price you can finance is not necessarily the right budget. If all available funds go into the acquisition, an unexpected repair and a change of tenant can already create pressure. Keep acquisition funds, transaction costs and future liquidity reserves separate in your planning.

2. Request an organised set of documents

Ask for a clearly structured data room or folder. Record the date of each document and identify missing items. An old condition survey or an unconfirmed rental schedule should not silently become the current basis for your decision. A simple register with columns for the document, its date, the outstanding question and the responsible person makes follow-up easier.

• A current land register extract and relevant supporting documents for recorded rights and encumbrances.
• The rent roll, leases, amendments and documented information about vacancies and payment arrears.
• Several years of property accounts, the management agreement and key maintenance and insurance documents.
• Approved plans, floor-area information, known alterations and available technical reports.
• Records of completed replacements, forthcoming work and any cost estimates or contractor quotations.

3. Reconcile the rent roll with supporting records

A spreadsheet showing annual rents is a useful starting point, but it does not establish sustainable income. Compare the figures for each unit with the lease and recorded payments. Keep rent excluding ancillary charges separate from advance payments for those charges and from other receipts. Investigate differences: is a unit vacant, is there a temporary discount, or has an agreed change not yet taken effect?

Check whether garages, parking spaces and storage rooms are shown separately. In your own assessment, current contractual rents, actual cash receipts and hoped-for additional income should remain three distinct figures. Do not treat an expected rent increase as secured revenue. Have its legal and commercial feasibility assessed separately rather than building the financing around it.

4. Read the land register alongside the PLR cadastre

The land register records matters including ownership, easements and mortgage rights, as explained by the Canton of Zurich. Separately, swisstopo describes the cadastre of public-law restrictions on landownership, known as the PLR cadastre or ÖREB-Kataster in German, as a source for the main public-law restrictions affecting land. The two sources answer different questions; neither replaces the other.

Have unclear entries and their supporting documents explained. Establish, for example, the legal basis for access and what further checks a proposed change of use requires. An empty area on a plan is not evidence of an approved development opportunity. If the purchase price only makes sense with an extension, investigate feasibility with the municipality and the relevant specialists before committing.

5. Turn the condition review into an investment plan

A freshly painted staircase says little about pipework, the roof or building services. Arrange a technical inspection and ask for observations, assumptions and documented defects to be distinguished. The report should identify priorities and further investigations, not merely list possible problems. Areas that could not be accessed should remain explicitly recorded as unchecked.

Translate the findings into a phased capital plan: what requires immediate attention, what may be needed over the next few years and what is still uncertain? Consider connected work together so that an isolated short-term measure does not make a later overall solution unnecessarily expensive. Our guide to energy-efficient renovation in Switzerland explores the coordination of the building envelope, technical systems and planning. Cost ranges remain estimates until sufficiently detailed quotations are available.

6. Unpack the headline yield

Gross rental yield compares annual rent excluding ancillary charges with the purchase price. It is an initial comparison measure, not spendable income. UBS also distinguishes between several return measures in its introductory guide. When comparing figures, therefore, establish exactly which costs and capital amounts each calculation includes.

Consider this deliberately simplified, hypothetical example. A building costs CHF 3,000,000 and generates CHF 120,000 in annual rent excluding ancillary charges, before owner expenses. Its gross yield is 4 per cent. Deduct illustrative annual owner expenses of CHF 25,000 and a CHF 6,000 planning allowance for lost rent: CHF 89,000 remains, or approximately 2.97 per cent of the purchase price. Financing, tax, transaction costs and major replacements are not yet included. These assumptions are neither market benchmarks nor a recommendation for a particular reserve.

Next, prepare a separate cash schedule showing when interest, agreed loan repayments and actual building work will require payment. A planning allowance is not the same thing as an invoice already paid. If money is set aside and later spent, avoid deducting the same expenditure twice in the overall calculation. Alongside the base case, examine a scenario with a longer reletting period and higher costs.

7. Prepare financing and management together

Discuss financing with the lender early and provide the property-specific records. Do not automatically apply owner-occupied mortgage assumptions to a rental investment. What matters is the valuation, equity contribution and conditions the lender confirms for this building and your circumstances. Our comparison of SARON and fixed-rate mortgages provides additional background when considering interest-rate periods.

At the same time, decide who will be available after completion, approve repairs and review the accounts. A property management proposal is easier to assess when the included services, additional fees and responsibilities are explicit. Plan the handover of documents, keys, meter readings and unresolved matters. An attractive building needs an effective operating arrangement, not just a signed purchase contract.

8. Make uncertainty visible before deciding

Summarise the result on one page under three headings: verified facts, supported assumptions and unresolved risks. For each important gap, identify the next action and the professional responsible. Missing rental records, inaccessible parts of the building or an untested extension proposal are not minor details if the calculation depends on them.

OWNY.CH’s assessment is straightforward: good due diligence is not about accumulating the largest possible folder. It should establish whether this particular building fits your objectives, financial resources and willingness to take responsibility. Where a central question remains unanswered, an additional check is more useful than an apparently precise yield calculated from uncertain inputs.

Frequently asked questions

What does due diligence mean for an apartment building?

It is a structured review before purchase covering legal records, leases, building condition, income, expenses and management. The scope and professional involvement should reflect the property and the risks identified.

Are the rent roll and sales brochure enough?

No. They are starting points. Important statements should be reconciled with leases, accounts, legal records and a technical inspection. Missing evidence should remain explicitly recorded as an unresolved question.

What is a good yield for a Swiss apartment building?

There is no universally suitable percentage. Location, condition, risk, capital expenditure and financing differ. Compare consistently defined measures and supplement them with a cash-flow plan.