Help with the choice of wall materials and insulation

[berju]

Thank you for all your advice, I will see a consultant tomorrow who I hope will enlighten me.
When I speak of a builder it is because I am a little taken by the time, indeed I have not enough time to find the financing and for that I need a contract or estimate to put together the file.

[fthanron]

Hello aerialcastor,

Bypassing the DTU is always possible as long as the mason and the client agree on the decade.

Regarding beche insulation, I have never seen a mason implement it by my home but it is commonly practiced in some neighboring countries.

@+

[primrose]

good evening everyone
I read this topic with interest, and found that not many people have opted for siding.
I am soon planning to insulate the walls of my house on the outside with extruded styrodur panels followed by rafting and wood or pvc cladding (a product that is widely used today) I have recently seen companies do this kind of work.
The 1st solution: rafting of 50 mm on the plaster and 40 mm styrodur between the rafters then horizontally siding in pvc or cream painted wood guaranteed for 10 years.
The second solution: insulate the whole wall with styrofoam, then rafter 30mm over the styrofoam, then siding as in the first case. I am wondering what is the best solution. If someone has good knowledge in this matter , that will give me great pleasure and thank you in advance.
This work does not seem complicated to me, and I plan to do it myself. Cordially.

[dedeleco]

The external insulation is worth it to put a nice thickness is 150 to 200 mm or even more in straw.
So 40mm does not seem sufficient to me.
In addition, the windows in the middle of old walls become thermal bridges and they must be moved outwards to obtain efficient insulation dividing the thermal losses by 10 !!

[aerialcastor]

40mm is not a lot. Why limit yourself to so little?

Styrofoam between chevron is not a good idea. Usually we cut the insulation 1 or 2cm larger so that it sticks well on the edges. STyrodur is far too stiff to use this technique. Suddenly it will not stick everywhere and it will create thermal bridges.
Then at the ecological level it is one of the worst insulators.

[primrose]

Hello to you
Thanks to the people who gave me advice, and I totally agree with you, and I will put at least 15 cm thick. But what I do not understand well, I saw near my house , a company specializing in exterior insulation which fixed 40x40 rafters vertically on the plaster at 30 cm intervals and we cut in two the styrodur sheets 60 cm wide and 3 cm thick, then fixed beige pvc imitation wood cladding horizontally, below near the ground a ventilation grid. what do you think of this work?
Kind regards.

[dedeleco]

3cm of well-ventilated insulation between the insulation and the old wall, seems a very unnecessary expense to insulate better !!!
A conjurer's illusion or placebo effect !!!!

[Obamot]

3cm Styrodur versus plaster with ventilation? Are not cold in the eyes guys

Is that for Les Hauts de Hurlevent?