The Residential Tenancies Board is trying to close the loophole that allows landlords evict tenants during renovations.
In new guidelines published today, the RTB says maintenance or repairs aren't enough to make people leave.
Some landlords have been accused of using renovations as an excuse to bring in new tenants at higher rates.
"What we're trying to say is it's not really about an upgrade of the bathroom in a property", says RTB director Rosalind Carroll.
"It's more ... Has the property been extended? Did you add a bedroom?"