Turning a one bedroom into a two bedroom

I live in an old building where half the lots are two bedroom and half are one bedroom. Two bedroom lots over two bedroom lots. One bedroom lots over one bedroom lots. Bedrooms over bedrooms, kitchens over kitchens. All are laid out the same way

An owner wants to totally renovate his one bedroom lot and turn it into a two bedroom. Owner has spent money on engineering and architect plans. Owner also wants to relocate the kitchen.

At the first EGM, the motion for change was soundly defeated 20 against and 2 for. After various “we will sort this in NCAt, you are being unreasonable threats, the owner has re-jigged plans and has put the  motion again. There remains the issue of turning a one bedroom into a two bedroom and moving a common property wall.

Is the following, in Flat Chat’s view, sufficient argument at NCAT , given applicant must prove owners are being “unreasonable”

1. Is it unreasonable to refuse the owner permission to change a one bedroom into a two bedroom because other owners are all on the same water bill (no one has own water meter and to do so is cost prohibitive) and an increase of persons may increase common property maintenance? Fewer availability of clotheslines and share washing machines? Longer waits for lift?

Owners are concerned that approval for an owner to change a one bedroom into a two bedroom could create a run of others wanting to do the same and potentially all one bedroom could become two bedroom.

Thank you.