Average Cost To Convert Side Garage To Bedroom/Showerroom Etc

[Barquentine]

Small terraced modern design houses - each with a garage to left underneath upper floor that overhangs garage entrance & small car port.
What would the average cost be to convert that to a bedroom and a loo/showerroom? This is in London. Several houses neighbouring have done that. I think mother-in-law should do hers.

[The Builder]

I'm afraid I'd have to ask you 100 questions before I could even attempt to help, Barque.
If I were actually there, I could have a look around and answer them easily.

We're often asked on here for rough guides, but it is really quite impossible. Try to find a local builder or two to take a look. It really is the only way.

I know it's difficult, but look for someone who will take a little time over it. Do not rely on someone giving you a figure "off the top of his head".
(I really hate that expression. I get it all the time at parties!)

Go on then............
Allow 15k for a (very) basic job.
25k for a full-spec good quality one.
It's a very easy job to do badly ;o)

.... and don't forget the 20% VAT

[Buenchico]

Possibly good starting points:
https://www.checkatrade.com/blog/cost-guides/garage-conversion-cost/

https://householdquotes.co.uk/expand-your-home-with-a-garage-conversion/

[jno]

or ask one of the neighbours who they used and how much it cost? (And whether they like the result.)

[Barquentine]

Thanks for these excellent answers. We got quoted £8000 just to change the bath in the upstairs bathroom to a shower! That was because the wall one side was "too small" (this is third hand so I may have misunderstood)so loo has to be moved and shower put on other side - so basically total new bathroom. So £15k sounds very reasonable for a new bedroom and showerroom downstairs.