Soil insulation: nothing, under slab or under sanitary void

[airsp]

Hello,

In our renovation project, I eventually consider ground insulation.

1. Is it very useful and necessary (knowing that the house is ranked G)?
It is better to isolate even more the attics lost to pass them from (R = 5 to R = 10)

2. if we go on the isolation, two possibilities:
- it is insulated below the crawl space (it is 60cm)

I find it hard to see what can be done: "hanging" glass wool (blah), cotton wool (it's wet so a priori not), I possibly see the wood wool in panel with laying of rafters and covered with cladding (all this under 60 cm)

- it is insulated on existing tiles
in the rooms with parquet flooring: insulation between the joists with mineral wool or natural wool;
in the other rooms: collages of XPS + slab + tiling.

which allows me long, expensive and complicated.


What are your opinions ?
Thank you

[dedeleco]

Given your complete renovation, roof and extension, you have better invest in a low-energy home (exterior walls, displaced windows, floors, waterproofing, VMC double flow, Canadian well, wood, etc ...!
It's expensive, but during an expensive renovation, the extra get a result consistent with the new 2012 standards, with good specialists, is worth it and values ​​the house for the future, like new!
See econology for knowledge, and others as www.fiahabitat.com
and compare the various opinions.
Otherwise, if the roofs are insulated to 1980 standards, 1990, it is necessary to isolate before, all that is not, isolated, and of big surface, walls, after, if necessary, less cold soil, windows, etc.? by interior or exterior following place. (Exterior insulated walls require moving outward, the windows of the thickness of the old wall to remove the thermal bridge).

It is necessary to make the balance sheet, saving of heating by year divided by the corresponding investment to know the time of reimbursement of the expenses and to judge of its interest, also according to the future increase of the price of the means of heating, almost certain, but of how many ?????.

For this reason during a renovation imposed for comfort or aesthetics, this expense and more, becomes easier!
I think that to protect yourself from the future, it is good to take or keep a wood heating in general, with exchanger and circulation, air or water, (not only pellets that are and will remain, almost as expensive as electricity, gas of city ​​and oil).
Give more information about your home, year, area, features, area, and read a max of documents.