"Landlords must respond to a tenant's request to make a change within 21 days," the service says.
The law change will "ensure that tenants can add minor fittings such as brackets to secure furniture and appliances against earthquake risk, baby proof the property, install visual fire alarms and doorbells, and hang pictures," the service says.
But in an online landlord chat group, investors complained that they wanted more information and asked about how significant other changes to their properties could be.
Minor changes are defined in the new act as those which present no more than a low risk of material damage to the premises and would allow the premises to be returned easily to the same condition. The changes can't pose a risk to health or safety.
The new act also ensures tenants return the place back to what it was before the changes they paid for.
"If a minor change is made in accordance with a request under section 42A, the tenant must, on or before the expiry of the tenancy, return the premises to a condition that is substantially the same as the condition that the premises were in before the minor change was made," the Act says.
The Real Estate Institute has released a more refined list of examples of minor changes.
In an information sheet published last August, REINZ summarised major changes and included financial penalties available for law breaches. Depending on the circumstances, REINZ says minor changes could include:
• Installing minor accessibility changes that improve safety for disabled people such as visual alerts for fire, security alarms and doorbells, where this has low impacts and will be reversed at the conclusion of the tenancy;
• Securing furniture or appliances to protect against earthquake risk or to make a property child safe;
• Installing dishwashers and washing machines;
• Installing a baby gate;
• Affixing child safety latches to cupboards;
• Installing shelving;
• Installing television aerials;
• Installing gardens when these can be returned to the original state once the tenancy ends;
• Installing curtains and window coverings;
• Installing internal locks if they are compliant with fire safety laws;
• Installing picture hooks.
Gary Lin, the Auckland landlord with properties valued at $13m, said he generally had no issue with tenants being able to seek these changes.
The list of what constituted minor changes was not unreasonable, he said.
"If the tenant is willing to pay for these upgrades, fantastic go for it. Picture hooks yes can be a problem if they overdo it and leave small holes on walls, but I'm not OCD on that and don't care," Lin said.
One tenant asked for a green wall to be white and offered to paint it, so Lin said he had bought the 10L of paint and told the tenant "go for it".
"Usually good tenants who want to make changes actually improve the property," Lin said.
However other landlords have expressed fear and concern, saying what someone thinks of as minor, another person could see as major.
"No end of dramas coming to this industry soon," said one investor on social media.
"The simple answer is up your rents and move on, 'cos whatever way you slice it's gonna cost a lot more to be a landlord. Sooner or later, many of us will feel the wrath of the lastest RTA meddlings."