Exposé due diligence for expats buying property in Germany

You found an apartment or house in Berlin, Munich, or somewhere else in Germany. The photos look good, the broker says demand is strong, and the Exposé shows attractive numbers.

That’s usually the easy part.

What many expats underestimate is how easy German property economics are to misread. A deal that looks solid on paper can quietly become expensive once taxes, WEG costs, renovation risk, financing structure, or energy issues enter the picture.

Good due diligence is not about replacing your Makler, mortgage broker, or Steuerberater. It’s about checking the assumptions before you commit serious money.

Before signing anything, most buyers should verify a few core areas:

First, check whether the asking price actually fits the micro-location, condition, and realistic rental potential, not only the broker narrative.

Then look at the Kaufnebenkosten. Many expats focus only on the purchase price and forget that Grunderwerbsteuer, notary costs, Grundbuch fees, and broker commissions can easily add another 10–15%.

If it is an apartment (ETW), inspect the Hausgeld, reserve fund situation, and possible Sonderumlagen. Weak WEG finances often become painful later.

Rental assumptions also deserve stress-testing. Cold rent expectations, vacancy periods, local rent caps, and realistic re-letting scenarios can completely change the cashflow outcome. The analysis should also differ depending on whether you buy as an investor or for self-use.

Financing matters too. Residence permit type, available equity, and expected loan-to-value ratios can influence what banks are willing to finance, even though final approval always stays with your financing advisor.

Tax assumptions are another area many buyers oversimplify. AfA, Sonder-AfA, and KfW-related incentives may improve the economics, but they depend heavily on structure and eligibility.

And finally, there is the energy question. A modern kitchen means very little if the building carries long-term renovation risk because of poor energy efficiency.

This is exactly why many expats no longer rely only on spreadsheets or generic AI tools. German real estate has too many local rules, edge cases, and interconnected assumptions. WEG structures, Grunderwerbsteuer differences, AfA logic, and financing realities rarely fit neatly into a simple calculator.

Immowiser was built to bridge that gap. It stress-tests an Exposé in English or German and gives one structured, deterministic verdict with transparent assumptions, confidence scoring, and next-step guidance. The result is not legal or tax advice. It is a decision-support memo you can take into conversations with your Makler, mortgage broker, or Steuerberater with far more clarity.

Your advisors still own the final decisions:
Maklers handle search, viewings, and negotiations.
Mortgage brokers handle financing approval and loan structures.
Steuerberater handle tax filing and legal tax interpretation.

Immowiser simply helps buyers pressure-test the numbers before they commit.