Internal insulation on external wall

Hi. I live in a Victorian terrace house. I've got builders starting in a week. They're going to strip some damaged plasterboard off an external brick wall, which has been applied by dot and dab. I had a survey recently and the surveyor recommended adding insulation.

This is the product I thought I'd order:

Does that look like a reasonable choice? Grateful for any advice. Thanks.

Product is ok and you need to follow the data sheet application.
I guess you don't have a cavity wall, just a single skin?

CharlieDIY on YouTube has done several videos trying out different systems.
Maybe look at those and decide which is best for you.

You can also phone the technical helpline for the product

Thanks. Yes, it's just a single layer - not a cavity wall.

Looking at CharlieDIY's comments on u-value, it looks like the 62.5mm Unilin Safe-R SR/TB achieves 0.33 on solid brick. So I think I'll need to get the 72.5mm one, which brings it down to 0.29. It's a shame to lose to much much space, but I guess another 10mm won't hurt!

Thanks for your help.

I'm getting some pushback from the builder I've hired to install this.

I settled on the 72.5mm Unilin Safe-R SR/TB to achieve a u-value that I think complies with building regs. He says he thinks 60mm insulation plus 12.5mm board is too thick. He's recommended thinner options.

We talked about this one, which they sell in Wickes etc: https://www.wickes.co.uk/Knauf-XPS-...ed-Plasterboard---27-x-1200-x-2400mm/p/163699

It looks like the thickest version of this Knauf board is 55mm, which on solid brick only achieves a u-value of 0.45.

I'm not sure where the builder's objections are coming from. I guess the thicker types of insulated plasterboard are harder to cut and install. But is it really that much more difficult?! I'd have thought the main issues with the thicker (62.5/72.5mm) boards are cost and loss of space. Surely those are my problems, not his. Why does he care? I'm not sure what I'm missing.

I'd be grateful for any advice.

There is a specific saw for cutting that make it easy.

Last one I fitted I just use 50mm insulation then stuck on plasterboard over as it works out cheaper.
Not something I've done loads of

Thanks. Is this the one? https://www.wickes.co.uk/Bahco-PC-22-INS-Profcut-Insulation-Saw---22in-550mm/p/262380