Modernisation notice: your rights from the first letter
The notice starts a short deadline for objections, and it fixes how expensive the work may later become for you.
Checked by Radif Partners · Editorial policy · Method
Check the announced increase
Increase per month
€83.33
| Before the cap | €83.33 |
| Six-year cap | €3.00/m² |
| New rent | €703.33 |
Before modernising, a German landlord must announce the work in text form at least three months before it starts (Section 555c of the Civil Code, BGB): its nature and scope in outline, the expected start and duration, the expected rent increase and the expected future service charges. The tenant generally has to tolerate the work. Circumstances that would cause you hardship (Härte) must be reported in text form by the end of the month after the notice arrives (Section 555d(3)). By the same date you can terminate the lease with special notice. Once the work is done, the annual rent may rise by 8 % of the costs, minus the share for repairs and capped at €3 per m² over six years. Example: notice on 20 October 2026, work no earlier than 20 January 2027, hardship objection by 30 November 2026. The announced increase is €133.33 a month. If the landlord later bills €153.33, that is 15.0 % more, and the increase only falls due six months later, from 1 March 2028 instead of 1 September 2027.
What counts as modernisation
Section 555b BGB lists the building works that count as modernisation (Modernisierung): measures that permanently save final energy for the flat (energy-saving modernisation), installing or setting up a heating system within the meaning of the Building Modernisation Act (Gebäudemodernisierungsgesetz), measures that save non-renewable primary energy or protect the climate, cut water consumption, raise the practical value of the flat, provide a first fibre-optic connection, permanently improve general living conditions, works the landlord carries out because of circumstances beyond his control, and the creation of new living space. Plain repairs are not included: the landlord pays for maintenance (Erhaltung) himself, and its share is deducted from the modernisation costs.
What the notice must contain
Under Section 555c(1) BGB the notice must be given in text form at least three months before work starts. An unsigned letter or an e-mail is enough; a notice pinned up in the stairwell usually is not, because it is not delivered to you. The law requires:
- the nature and expected scope of the work in outline, so that you understand what will happen in your flat and to the building;
- the expected start date and duration;
- the amount of the expected rent increase, if the landlord intends to raise the rent under Section 559 or 559c, together with the expected future service charges.
The landlord should also tell you about the form of and deadline for a hardship objection (Section 555c(2)). That is not a condition of validity, but if it is missing you are not bound by that form and deadline. For energy-saving work he may refer to generally recognised standard values for the quality of building components. The notice can only be skipped altogether for works with a negligible effect on the flat and a negligible rent increase.
Your deadlines once the notice arrives
Receipt of the notice starts two short deadlines that end on the same day. In the example the notice arrives on 20 October 2026.
| What | Deadline | In the example | Basis |
|---|---|---|---|
| Earliest start of the work | three months after receipt | 20 January 2027 | Section 555c(1) |
| Hardship objection in text form | by the end of the following month | 30 November 2026 | Section 555d(3) |
| Special termination by the tenant | by the end of the following month | 30 November 2026 | Section 555e(1) |
| End of tenancy if notice is given on 25 November 2026 | close of the month after next | 31 January 2027 | Section 555e(1) |
The hardship objection
Under Section 555d BGB you must tolerate modernisation unless it would cause you, your family or a member of your household hardship that cannot be justified even after weighing the interests of the landlord, the other tenants and climate protection. The law gives no list of grounds; a serious illness or a disability that cannot be reconciled with the building work are typical examples. The future rent plays no part in whether you must tolerate the work; it is only examined when the increase comes.
Report hardship grounds in text form by the end of the month after the notice arrives. The deadline only starts if the notice complies with Section 555c. If you were prevented through no fault of your own, you can add grounds without delay; but grounds against the rent increase must reach the landlord before work begins. A tenant who first mentions financial hardship when the increase letter arrives is usually too late under Section 559(5) BGB. The exception: the actual increase exceeds the announced one by more than 10 %.
The special right to terminate
If you would rather not wait for the building work, Section 555e BGB lets you terminate with extraordinary notice until the end of the month after the announcement arrives. The tenancy then ends at the close of the month after next following your notice. No reason is needed, and the right applies even during an agreed minimum term. It does not apply to trivial works under Section 555c(4).
From notice to rent increase
Once the work is complete, the landlord may raise the annual rent by 8 % of the costs spent on your flat, minus what maintenance would have cost anyway and minus any grants. Under Section 559b BGB the increase must be declared in text form, with a calculation based on the actual costs and an explanation. The rent goes up from the start of the third month after the declaration arrives. That date moves six months later if the work was not properly announced or the actual increase exceeds the announced one by more than 10 %.
| announced | billed | |
|---|---|---|
| Costs for the flat | €24,000 | €27,000 |
| minus maintenance share | €4,000 | €4,000 |
| chargeable | €20,000 | €23,000 |
| 8 % a year | €1,600.00 | €1,840.00 |
| Increase per month | €133.33 | €153.33 |
| Cap of €3.00 per m² over six years | €210.00 | €210.00 |
| New net cold rent | €763.33 | €783.33 |
The billed increase is 15.0 % above the announced one, so more than 10 %. If the increase letter arrives on 10 June 2027, the new rent would normally be due from 1 September 2027; instead it is due from 1 March 2028. The cap of €3 per m² does not bite here, because the rent before the increase was above €7 per m² and the increase stays below the limit; for a rent under €7 per m² the cap would be €2 per m². The modernisation calculator reworks all of this with your own figures.
Two special cases in the notice
Simplified procedure. If the costs for the flat are no more than €10,000, Section 559c BGB lets the landlord deduct a flat 30 % for maintenance instead of working it out. The notice must say so, and it then need not state future service charges. With costs of €8,000 that gives €37.33 a month. In this procedure there is generally no hardship objection to the increase, and the landlord cannot claim another increase under Section 559 or 559e for five years.
New heating system with a grant. If the landlord installs a heating system that qualifies for public subsidies and takes up the funding, Section 559e BGB lets him pass on 10 % of the costs minus the grant, with a flat maintenance deduction of 15 %. The increase is capped at €0.50 per m² over six years. With costs of €30,000 and a grant of €9,000, the formula would allow €137.50 a month, but the cap only permits €35.00.
What to do with the notice
- Note the date it arrived and work out both deadlines: hardship objection and special termination, each by the end of the following month.
- Check that every required detail is there, especially the expected increase and the future service charges. If something is missing, the hardship deadline does not start and any later increase falls due six months later.
- Report hardship grounds, financial ones included, in text form before the deadline, as a precaution.
- Recalculate the announced increase with the small calculator above and compare it with the later increase letter.
With an index-linked rent modernisation increases are only allowed in narrow cases, and during a graduated rent not at all. If the building work impairs the flat, a rent reduction (Mietminderung) may come into play; for energy-saving modernisation under Section 555b no. 1, however, any impairment is disregarded for three months (Section 536(1a) BGB).