But there are some strategies to make the process smoother.
The sale process can be very unsettling for a tenant and most property managers have seen their fair share of tenancy disasters arising from unthinking or unfeeling sellers and sales agents, eager to promote a sale.
Some things we hear about include: turning up with a buyer unannounced at 5.30pm on a Sunday, threatening to evict the tenant who refuses access - yes, that happens quite a lot - buyers turning up on their own to look through without the owner or agent present, owners taking heaps of interior photos for advertising, including pictures of the tenant's possessions, and general disregard for the tenants' rights.
Any unpleasantness or confrontation can be avoided by including the tenant in the process.
Agree on set viewing times and/or open homes. Agree that no unannounced viewings will take place. Maybe reduce rent during the process and treat the tenant as a real person, not an obstacle.
One popular idea is to offer the tenant a cash incentive to stay and be co-operative.
When the sale happens, a nice little cheque is handed over.
We have seen sums from $500 and upwards pass from owner to tenant, so that can be a very useful idea.
Some tenants react well and some not so well.
They will either go out of their way to be tidy and co-operative, so a new landlord will want them to stay and not put the rent up, or they will be very negative with comments such as: "The rats are a real nuisance" or "The house leaks like a sieve in winter so we would want compensation for the damage to our clothes" and my favourite "You know the place is haunted after that murder here four years ago?"
A frequent reaction by tenants, when an owner decides to sell, is to relocate and give notice immediately, leaving the owner with no rent and a possible long wait for a sale.
Sometimes owners say: "But I can't have the place vacant, I need the rent to pay my mortgage."
That is not the tenants' problem, of course, so some simple and sensible arrangements can make the whole process smooth and stress-free.
- Richard Evans is executive director of Leading Property Managers of New Zealand Ltd and member of the Real Estate Institute of New Zealand property management group