Extension budget

[lolawoo]

Hi all, just about to embark on a single storey kitchen extension, and trying to budget for some nice-to-have extras. I know it's a bit of a piece of string question, but I'm trying to include estimates for the following, so if anyone can help it would be much appreciated. Thank you

Bifold doors with integral blinds (aluminium, 2.8m)
Quartz worktops including fitting
Karndean flooring including fitting
Wet under floor heating including plumbing etc

My bi folds for 3.6 m - no blinds were around 4K as went for skin frame

Quartz including full height back splash - 3,600

Rule of thumb £1k per metre bifold, £1.5k with integral blinds. At least that was our experience 4 years ago. Went with the blinds. No regrets but we are VERY sun facing