Multiple advisers told TMM Online that bank panel valuers are struggling to cope with the weight of demand in the market, with valuations taking up to two weeks to come in.
The problem has affected first home buyers, which require a registered valuation if they have less than a 20% deposit.
Most big lenders require an RV to approve a home loan.
The delays are creating difficulties for clients at auctions, with buyers unable to compete if they don't have an RV.
Registered valuations can cost about $1,000, meaning some clients have forked out a significant fee for a valuation but have been unable to get one in time.
"The turnaround times aren't there at the moment," said adviceHQ's David Green. "It's putting time and cost on to first home buyers, who are usually the ones requiring registered valuations.
"So if they see a house they like, and ask for a registered valuation, it could take a week or two. If the auction is brought forward, you don't have a registered valuation, so you can't offer, and you've spent $1,000 for nothing. It's causing a lot of pain for purchasers and vendors.
"The demand is overwhelming and placing a lot of strain on the system, whether it's valuations, banks, or builders, at the moment, it's overwhelming for everyone," Green added.
Sarah Bloxham of Lets Talk Mortgages said valuation turnarounds went from "one extreme to the other" in this market.
Bloxham said one client was forced to wait three weeks for their valuation, delaying a private sale.
She added the fees for quicker service were "really taking it out of first home buyers' pockets".
"I advise all clients to have a pot of around $5,000 for costs towards their home for the valuation, the build report and solicitor," Bloxham said.
Bloxham is currently advising clients outside of Auckland that they will have more chance of winning a tender if they go unconditional. However this means clients need valuations, leading to extra risks around valuations.
"The cost of valuations is soaking up their savings," Bloxham added.