The majority of Victoria's newest apartments are so small they would be considered unliveable in Sydney, and only one in 20 has three bedrooms or more, according to a state government report.

As Melbourne's high-rise construction boom hurries on, Planning Minister Richard Wynne has released a discussion paper seeking input on how to address growing concerns about poorly designed units.

By the middle of next year Victoria's long-awaited apartment guidelines are expected to be handed to the minister.

The reforms could see new regulations on access to daylight, ventilation, noise, accessibility and the size of units and their balconies.