The associate rule isn't met – letting to/free use by associates

If the daughter lives free of charge in the apartment and doesn't cover all the property's operating costs, this will be a tax liable benefit for her.

For example, if the parents own an apartment that could've been let out for NOK 10,000 per month, and the daughter lives in the apartment without paying rent or covering the property's operating costs, she will be tax liable for a benefit worth NOK 10,000 per month.

The daughter must declare the benefit of NOK 10,000 per month in her tax return. The tax rate is 22 percent. Accordingly, tax on free housing will be assessed to the total of NOK 2,200 a month.

Since the apartment provides no income for the parents, they won't be entitled to a deduction for costs related to the property.