Garage Conversion - Again ?

[wucheng]

Hi, I want to convert my garage and looking for some advice re insulation and building regs.

I have a double length garage which I want to convert the back half into a playroom (and convert the front half into a room in the future)

The back half (intended playroom) has a concrete block for a floor which is currently 90mm below the floor in the rest of the house.

The garage is single skin bricks (except for the wall attaching to the house which is standard house cavity wall).

How can I insulate the floor and walls to meet building regulations without losing too much space.

Pointers to where I can easily find this out would be fine - I understand the planning portal re ventilation and think I can sort the roof insulation but the floor is the real problem due to not wanting to raise it too much.

Help !!!

 

[noseall]

The back half (intended playroom) has a concrete block for a floor which is currently 90mm below the floor in the rest of the house.

What do you mean by 'concrete block' floor?

Block paving?

What type of roof is on the garage?

 

[wucheng]

The 'concrete block' is a solid concrete floor.
the roof is a flat felt roof - is this relevant though ?

Thanks

 

[noseall]

You may be able to design the thermal aspect of the conversion so that you could have say 70mm celotex insulation with a floating chipboard covering for the floor. 70mm + 20mm = 90mm.

This may mean increasing the wall and roof insulation.

The external walls are likely to need a minimum of mebbe 140mm insulation. Build say 100mm stud frame with 100mm between studs and 40mm across studs prior to plasterboards.

It may be in your best interests to re-deck the roof using the warm deck method of insulating then re-felt.

 

[wucheng]

Ah, ok that makes a bit more sense now.

I had thought it applied to each side of the room completely independently, not that it could be calculated as the whole room.

Would it be worth getting an energy report for the house before the conversion and then another report afterwards to prove the difference or just one afterwards.

Now I need to find what insulation materials best fit in terms of size space and insulation values. should be plenty of choice nowadays though.

Thanks