Garage floor make up

[roscopeco2000]

Hello I am converting our garage next year into a habitable room. The issue I have is the garage floor is at the same level as the main house. Will building regs let me over insulate the walls and roof to composate for the lack of insulation in the floor? If I have to insulate I would hopefully use the thin kingspan insulation 20mm and overboard with 22mm structural ply and have a step. I really don't want to exgavate the floor, the annoying thing is the main house doesn't have any floor insulation as 80s Bungelow. Thanks advice welcome 

[nod]

I did exactly that on a previous home It was a modern build with the slab being reinforced so would have been expensive the hack up 

BC did insist that I Kingspan the rafters Then fix 18 layer multi foil Then counter baton Then 100 mil insulated PB to the ceiling 

Most of which I’d of done anyway 

[roscopeco2000]

So you got away with no insulation in floor? I really don't want step to get some insulation in floor

[nod]

13 minutes ago, roscopeco2000 said:

So you got away with no insulation in floor? I really don't want step to get some insulation in floor

There was 25 mil under 

Hardly a thing really

[juncopartner]

I personally would not insist on the floor being upgraded if it meant there was a step, I would, however, be looking for some compensatory measures ie ugrading the level in the roof or walls if practical, or even some additional measures to the existing house such as topping up the insulation in the roof.  

[TonyT]

A good way of cutting concrete floor is to hire the floor type saw, push along with depth stop, keep the water on and it keeps the dust down, regular parallel lines will make it easy to knock out.

 

only one chance to insulate so best take it, energy costs only ever increase in the long run