First, second and third fix are terms used in the UK domestic construction and commercial construction industries to describe all the internal carpentry work needed to construct a home from the foundation to the plastering of the internal walls. First fix includes the erection (in the case of timber frame construction) of the walls, ceilings, floors, routing of electrical cables and plumbing in of pipes for water supply, all completed before the walls and ceilings are plastered.
Internal Carpentry Stages
1st fix (before plaster)
Stairs
Door casings
Window boards
External doors
Loft access noggings
Bay window cills
Bulkhead
Studwork
SVP boxings
2nd fix (After plaster)
Internal doors
Fire doors
Airing cupboard shelves
Skirting boards
Complete stairs
Pipe boxings
Wardrobe shelves
Loft hatch
Cover strips
3rd fix (After Painting)
Door furniture
Door stops
Door closers
Refit shelves
Hanging rails
Bath panels
Shower panels
External door furniture
Plot snagging