Garage conversion insulation

[daffdill]

We recently had to pause our garage conversion midway as we had some other unexpected renovation costs, planning to finish the conversion in a couple of months. So far the garage has only been insulated and boarded, I assumed insulation boards would be used but it turns out the builders have only used wool rolls insulation for the walls, DH was managing the project and didn’t tell me this. Would this be sufficient insulation for walls? Would this still meet building regulations. We still have to insulate the loft and floor but I’m now wondering if we should just take the boards down and replace with insulation boards?

It sounds like Rockwool was used. It is good for insulation as fire resistant, noise dampening, has thermal properties and manages moisture as water repellent and vapour permeable so prevents mould. It's more expensive than fibreglass. I have it in my garage where 1/3 was made into a utility room. If you have Rockwool you have a good quality product.

"We still have to insulate the loft and floor but I’m now wondering if we should just take the boards down and replace with insulation boards?"

Not an expert on building regulations but I believe they specify a minimum insulation value. As a previous poster has indicated rockwool gas its advantages, but you need a greater thickness of rockwool to have the same insulation value as celotex / kingspan or similar.