Having downlighters fitted does the electrician need the ceiling in to do it?

Cabling should be installed first, and a drawing showing where all the cables are, then cut hoes for lights once ceiling is fully finished.

All depends if there is access to whats above ceiling. If there is access after new ceiling installed I would do the whole installation in one visit, after the ceiling is installed. If there is no access I would install cabling, prepare plan of my spots before boarding up. Lights installation would take place after boarding up.

Yes

Ultimately it all comes down to a leap of faith. The big advantage of getting the ceilings up and skimmed beforehand is that the finish is better and it makes for a professional job. However, there is no denying that it runs counter-intuitive to instinct, inasmuch as if the spark's called it wrong; it isn't going to be an easy or cheap fix. Plans are definitely good. I would certainly want to see a map outlining the positioning of the proposed lighting system, including cable routing. It should also show the dimensions of the room and positioning of joists and any other significant features. Photos also help. Tip: LED slimline downlighters are a clever solution to coring a hole smack in the middle of a concealed joist. They are plasterboard depth with a 100mm, or 4-inch diameter, hole. This means you can normally fish, see, record concealed cabling even if you've bulls-eyed the beam. These lights fit flush to the ceiling and come in various shades of white. Should be fitted with an approved termination unit, but are straightforward to install; and extremely cost efficient to run and easy to maintain. Given, that they can also be a get out of jail card, these fittings have a lot going for them.