Take photos and send written notice to the landlord immediately when you find mould or persistent damp. Describe where the problem is, when you discovered it, and ask for an inspection and repair. Do not stop paying the full rent on your own.
Do this in the first 24 hours
Document the problem before you clean, move or repair anything. Photos and written messages may become important if you and the landlord later disagree.
Follow this order:
- Take overview photos and close-ups of mould, water marks and condensation.
- Write down the date, the room, and how long the problem has been visible or smelled.
- Keep messages, advertisements, the tenancy agreement and move-in photos.
- Send an email or message to the landlord the same day.
- Ask for a response, an inspection and a plan to remove the cause.
- Limit further damage if it is safe, for example by drying up water after a leak.
A notice about a defect is called a complaint. Husleietvistutvalget (HTU) says that you must make a complaint within a reasonable time, usually within 14 days. The notice should be in writing, explain what is wrong, and say that you require repair. You must also be able to show that the notice was sent.
If the tenancy agreement is difficult to understand, you can compare it with SamfunnPrep’s tenancy agreement checklist.
Who is responsible for the mould?
The landlord is generally responsible for ensuring that the home does not have mould. The home must have sufficient ventilation and heat sources. At the same time, the cause can be complex.
HTU explains that mould often results from a combination of:
- faults or weaknesses in the building, such as a leak or poor ventilation
- how the home is used, for example too little airing
- furniture placed close against cold exterior walls
- local weather and climate conditions
This means that neither the tenant nor the landlord should determine the cause based only on a photo. The landlord should investigate where the moisture comes from. If there is disagreement, an expert can measure moisture and assess the cause and severity. Ask to receive the report in writing.
You can air out the home, use vents and keep normal heating without accepting blame. Do not paint over mould before the cause is found. Surface cleaning alone helps little if a leak or wet structure still exists.
What should you write to the landlord?
A short and specific complaint is better than a long verbal conversation. You can write:
I discovered mould and damp on the bedroom wall on 25 July. Photos are attached. I ask that the cause be investigated and the defect repaired within a reasonable time. Please confirm within three working days when the home will be inspected.
Attach photos and other evidence. Also write about smells, water or rooms that cannot be used. If you speak by phone, send a message afterwards summarising what you agreed.
The landlord must be given an opportunity to inspect and repair the defect within a reasonable time. How long is reasonable depends on how serious the problem is and what needs to be done. An active leak or a room that cannot be used requires faster action than minor damage without spreading.
Can you claim lower rent?
You may be entitled to a proportionate rent reduction if the landlord does not repair the defect within a reasonable time. You may also be entitled to compensation for a documented financial loss.
First give the landlord an opportunity to repair it. Collect receipts if the mould damages belongings or you have to pay necessary extra costs. Contents insurance for tenants may be relevant in the event of water damage, but coverage depends on your agreement.
Do not stop paying the entire rent without a specific assessment. If you withhold money to secure a claim, HTU says that the amount must be proportionate to the defect and the claim. You must notify the landlord in writing why you are withholding money and how much. HTU recommends putting the amount into a separate deposit account that both parties control together.
To terminate the agreement means to end it immediately. This can only be considered when the defect is substantial. Wrongful termination may make you liable for payment. Get legal guidance before you move out and claim that the agreement has been terminated.
What if the landlord does nothing?
Send a new written deadline and choose the right place for help. Attach the first complaint and ask for a date for inspection and repair.
You can then:
- contact the municipality’s environmental health department if conditions in the home may affect health and you cannot remedy them yourself
- ask a tenant organisation, lawyer or other legal aid service to assess the claim
- submit a complaint to Husleietvistutvalget if the conflict concerns the tenancy
Helsedirektoratet states that the municipality supervises the environment and health. The rules also cover conditions in rental homes that the tenant cannot influence personally. The name of the municipality’s department may be «miljørettet helsevern», «kommuneoverlege» or «miljø og helse».
HTU can handle disputes concerning, among other things, defects, rent reductions and compensation. SamfunnPrep has a separate guide to complaining to Husleietvistutvalget. Keep the agreement, photos, messages, reports and receipts before you complain.
Mould and health
Persistent damp and mould should be investigated and remedied. FHI’s 2025 evidence review shows that damp and mould may be linked to health risks, but the evidence is uncertain for several types of symptoms.
Contact your GP or emergency clinic for a medical assessment if you or your child develops symptoms that worry you. Say when the symptoms started and where in the home the mould is located. In case of acute serious breathing difficulties, call 113.
A doctor assesses health, while a building expert assesses the home. A medical certificate alone does not show who is responsible for the damp, and a moisture report does not make a medical diagnosis. Both can nevertheless be useful evidence if the case becomes serious.
How to prevent it without accepting all the blame
Normal airing and heating reduce moisture, but do not solve building faults. Keep vents open, use extraction in the bathroom and kitchen, and let air reach behind large furniture. Report leaks and mould that returns quickly.
When looking for a new home, check smells, ventilation, basement walls and marks around windows. You can use the guide to finding a rental home in Norway.
SamfunnPrep can help you understand the process and gather documents, but the cause, health and legal claims must be assessed specifically. If you are new to Norway, you can find more practical steps in the first-week checklist.
