What you can write off depends on the building, and the rent you can charge on the rules where it is. Both, on your own numbers.
Your flat both ways
Run your numbers in the buy-to-let calculator, with the building's share and your tax rate: this shows your flat both ways.
Check the rent
What to know
-
An existing flat: its building year decides
2 % a year for a building completed from 1925 to 2022, 2.5 % before 1925, of the building's share of the price and purchase costs (§ 7 Abs. 4 EStG). The land isn't written off, and in cities it's often a large part of the price.
Building and land. Split in the contract, checked by the tax office.
The purchase contract can split the price between the two; the tax office checks the split with the finance ministry's own tool. The larger the building's share, the more there is to write off.
-
A new build: faster, and dearer
More to write off sooner, but a new build usually costs more per m², so its yield is often lower. The rent brake doesn't cover it.
3 % a year, or 5 % of what's left. The declining balance, for a recent start.
5 % of what's left each year applies where construction began, or the purchase contract was signed, from 1 October 2023 to 30 September 2029, for a new build bought by the end of the year it's finished (§ 7 Abs. 5a EStG).
The special allowance. Up to 5 % more a year for four years.
For a new rental flat in a building to Effizienzhaus 40 with the QNG seal, costing at most €5,200 per m² without the land, and let as a home for ten years, or it's taken back (§ 7b EStG). It brings depreciation forward rather than adding to it.
-
Renovations: how much decides how they count
Repairs count against the rent in the year you pay them. Past certain lines, they're written off over the years instead.
Ordinary repairs. In the year you pay them, or spread.
Repainting, a new boiler, like for like: they count that year (§ 9 EStG). Large ones on a building used mostly for housing can be spread evenly over two to five years (§ 82b EStDV).
Within three years of buying. Past 15 %, written off instead.
Repairs and modernisation in the first three years whose cost, without VAT, passes 15 % of the building's cost are added to the building's cost and depreciated (§ 6 Abs. 1 Nr. 1a EStG). Yearly upkeep doesn't count towards the 15 %.
Adding or upgrading. Added to the building's cost.
An extension, or raising the flat well above its old standard, adds to the building's cost and is written off with it (§ 255 Abs. 2 HGB).
How yours count is a tax adviser's question: Klarbooks, our sister service, finds one who works in English.
-
The rent you can charge
In areas the state has named, a new tenancy's rent may be at most 10 % above the local comparative rent, which the local rent index (Mietspiegel) shows (§ 556d BGB). The states' lists run until the end of 2029 at the latest.
Check the rent ↑The exceptions. A new build, a full modernisation, a previous tenant's higher rent.
A flat first used and let after 1 October 2014, and the first let after a comprehensive modernisation, aren't covered (§ 556f BGB). A previous tenant's higher rent can be kept (§ 556e BGB). Relying on one, you tell the tenant in text form, an email will do, before they sign; told later, it counts only two years after (§ 556g(1a) BGB).
Later rises. Capped, or set in the lease.
Towards the local comparative rent, after 15 months unchanged: at most 20 % in three years, 15 % where the state has named the area for this cap (§ 558 BGB). A lease can instead set the rises in advance (Staffelmiete, § 557a BGB) or tie them to inflation (Indexmiete, § 557b BGB).
After a modernisation. 8 % of its cost a year.
On top of the rent: 8 % of what the modernisation cost, a year, and at most €3 per m² a month within six years, €2 where the rent was under €7 per m² (§ 559 BGB).
-
Weigh the flats you're looking at
What to look at in a viewing and which papers to ask for: finding and checking a property. A flat that's let comes with its lease: buying a flat that's already let.
Primary sources checked on 26 October 2026: the statutes and official pages linked above.