More help required - how long to paint a house

[JugglingChaotically]

Terrace over 3 stories.
Or perhaps better estimate, is how long to paint a bedroom say 12 by 12? A stair case in Victorian (smallish) terrace?
Bathrooms all tiles.
Kitchen all cupboards.
And the time quoted inside and out is 10 weeks! And ££££££££.
Am rapidly losing faith in our builder!
I need something to measure just how sillly this is?
(Hoping it's not right!)
Tks!

10 weeks? is the plaster falling off every wall?

The cupboards would take longer than the room because they are more fiddly, a bedroom, if it just needs paining with no prep would be about half a day at most

With preparation our decorator took 7 days for three double bedrooms, 4 days for hall, stairs and landing and 5 days for kitchen/dining room/family room area with wooden kitchen cupboard doors outside only. We have some pictures rails etc and it needed lots of filling and sanding. Hope that helps.

Our decorator allows 1.5 days for a room. Includes thorough prep, sanding and filling etc then 2 coats, for ceiling ,walls and woodwork. He tends to do 2 rooms at a time so as not to disrupt the whole house and this gives him areas that can dry while he moves on.

Thanks all.
The builders time scale and £££££ is after the whole house had been stripped and either plastered or skimmed as required!
So minimal prep

Seems he's in fantasy land again.......