Fitting upvc window & door in shed frame - What size gap

[kujina]

What kind of gap if any, do I need around the frames when installing a upvc window & French door into timber shed frame (4 x 2's)?

I already have the second hand window and door, and I'm currently finishing the timber frame.

 

[wms]

normally 5 mm each side is what you would expect but it it goes into a timber frame then you will be ok, the 5mm is for expansion of the frame

 

[kujina]

I found a wickes instruction leaflet online as a pdf that says (page 11 under general informaton)

Brick or blockwork openings should be a minimum of 9mm larger to allow for adjustment and square fixing in the opening. Timber stud partitions should be made to the exact size ensuring that they are perfectly square.

WICKES EXTERIOR FRENCH AND PATIO DOORS PDF