Extension over garage

[LadyKooKoo]

As a general rule, is planning permission for this type of extension required? We will not be extending back, just building over what is already there.

Yes as it would be a 2 storey.

Plus depending on when & who built it it may not be as straight forward as you think as it depends if the foundations for the garage are to support the single storey garage or would allow a 2 storey.

I had a double garage one of which was already built over as part of the original house, but the garage that isn't built over is single skin (just brick, no cavity wall)

I have a double garage that I'd like to build over to make 1 bedroom 1 ensuite. Assuming the foundations are appropriate does anyone have an idea on price?

This has nothing to do with the question you asked but, if you go ahead, please make sure the floor is properly done. My mum's house (which we have recently sold) had dreadful damp in the bedroom over the garage because the floor had not been "sealed properly" (whatever that means). It was also a very cold room.