It is Australian Standards to put three coats on all bare surfaces. A large number of new homes, particularly project homes, are not getting the required amount of paint they should.
All ceilings should have one coat of acrylic sealer and two coats of ceiling paint, eg. ceiling flat or low sheen in wet areas.
All walls should have one coat of acrylic sealer and two coats of low sheen acrylic.
All doors, skirtings, windows, frames etc, if pre-primed can be undercoated and given either two coats of water based enamel or one or two coats of oil based enamel.
Externally, all eaves should get a minimum of two coats of acrylic and all bare surfaces, timber or render, should be primed and then two coats of your preferred finish product.
If you intend on living in your new home for more than 7 or 8 years and you don’t use a three coat system, you can be certain you will have problems. For example, paint peeling off your bathroom or kitchen ceilings and walls is a sure sign of no sealer or undercoat being used. Pay for a coat of acrylic sealer and you won’t have to worry about peeling paint down the track.