When Jordan Chapman bought an off-the-plan apartment in the Markets Residences in Belconnen in 2023, the contract he signed called it a "two-bedroom".
One of the bedrooms, however, does not have a window, and the latest amendment to the development application in December 2025 calls Mr Chapman's apartment a "one-bedroom plus study".
Mr Chapman said he had no idea the change had been made until other buyers started raising their concerns.
"It feels a little bit of a cheap way of getting people to think they're buying something a bit bigger than what it actually is," Mr Chapman said.
"Obviously it's not as advertised."
He is one of a group of buyers who are now considering a group action against the developers of the Markets Residences in Belconnen, saying they were given misleading information about the number of bedrooms in their apartments when they made their purchase.
Other buyers have told The Canberra Times they have been left confused and anxious since Sasha Trpkovski, the former sales director for the development, called an "informal information session" last week.
At that meeting, which was attended by about 100 buyers, Mr Trpkovski said many of their contracts had misrepresented the number of bedrooms they were buying.
Floor plans included in some contracts, which The Canberra Times has seen, had internal rooms with no windows labelled as bedrooms.
Those rooms would not be able to be marketed as bedrooms if the buyer wanted to sell in the future, Mr Trpkovski said.
Mr Trpkovski, who had also bought into the development and had his contract rescinded, warned buyers might also struggle to get a mortgage as settlement approached if the bank valued their apartment using the lower number of bedrooms.
A settlement date has not been confirmed, but with construction on site nearing completion, it is expected to be early next year.
Jacinta Scott's contract said her apartment had four bedrooms. She is now worried it would be valued as a three-bedroom plus study if she chose to sell in the future.
A floor plan attached to her contract called the apartment a "3 bed + 1" in the bottom right-hand corner, while the four rooms - including one with no windows - are all labelled as beds.
Ms Scott said trying to get information about the issue was often confusing.
"It's so difficult because you're sifting through DAs, you're looking for all this information, you're trying to figure out what clauses, what dates," she said.
"I don't think I'll ever, ever, ever buy off the plan again - ever. It's not worth it."
According to the Real Estate Institute of the ACT, a bedroom has to have a window to be considered as such under the National Construction Code.
However, a spokesperson for the project said the apartments would be built with the same number of rooms as in the contracts.
"The original marketing material was not inaccurate," the spokesperson said.
"All the applicable rooms in the apartments at The Markets Residences will be built and certified as Habitable Rooms. This means that a Habitable Room has been designed, approved and built to be used as a study or a bedroom or any alternative uses as per the definition."
Under the National Construction Code, a habitable room is a room used for "normal domestic activities" and could include a bedroom or study.
The spokesperson also accused Mr Trpkovski of inappropriately accessing buyers' personal information to call last week's meeting, an allegation he has denied.
This week dozens of buyers attended a meeting at Adero Law on Thursday, August 27 to discuss the possibility of a group action, Mr Trpkovski said.
Adero Law principal lawyer Andrew Chakrabarty confirmed several buyers had already approached the firm to issue rescission notices.
The contracts appeared to be "problematic", he said, but confirmation of a group action would come after due diligence was completed.
