Plaster boarding ceiling and new loft access

[houstonwehaveaproblem]

I’m about to replace an old ceiling with new plasterboard.

I need to create an access hatch. is it best to cut the access hatch in afterwards. As in board the whole room then use a pad saw to cut an opening between the joists?

I have some timber to build the hatch surround. How much should the surround protrude the new board before it’s plastered?
Thanks

 

[dontbelieveawordofit]

build the opening then board around it . your timber should be proud of the board by around 3-4mm . the ceiling can then be skimmed flat to the timber which will allow an architrave to sit flush with no gaps . tidy.

 

[houstonwehaveaproblem]

build the opening then board around it . your timber should be proud of the board by around 3-4mm . the ceiling can then be skimmed flat to the timber which will allow an architrave to sit flush with no gaps . tidy.

Thank you