
It will be located on the third floor under the roof. Not the best place, I know, but I’m already happy that I have that space. I will build according to all the info I’ve read in the books above and this forum. Room in room, according the little studio design from John.
Purpose of the room is to listen to music in excellent sound-conditions plus record some guitar and vocal stuff for my rock – metal band (electronic drums), and then mix it all down. The type of music I listen to is mostly hardrock - metal and beyond, but also pop music. So a wide variety. My speakers are a Tannoy 800 System, for the moment no subwoofer, but I'm thinking about it. I've learned to not play to loud anymore (ears !!), so most of the time it will not be louder than 80db, sometimes a bit more when it has to

The space I have, to build the room in, is 6,5m length * 3,5m width * 2,5m height. It’s located on the third floor, under the roof, so the front and rear are angled. See the sketchup picture, it's where the beams are drawn : "zolder1.jpg"
In the rear roof part there’s a window (double glass).
The floor is concrete (16cm) with another layer of 10 cm of what we call ‘chape’. That’s a mixture of sand (like the one you find on beaches), cement and water. It’s used to level all the electrical and water leads. On top of that there comes a finish of 1cm vynil (after the construction has ended).
The walls of our house are from inside to outside :
- brick wall (14cm)
- 12cm of recticel PUR isolation attached to the 14cm brick wall (excellent for thermal isolation, but acoustical close to nothing, because closed cells. Weight also close to nothing)
- 3cm air space
- 9 cm brick wall
- the outer leaf is anchored to the inside with metal hooks of about 0,5 cm diameter in the mortar.
See attachement "wall construction.jpg".
The right wall (see sketchup) of my space is also a double wall but from inside out :
- a brick wall of 9cm
- 12cm Pur isolation attached to the 9cm brick wall
- 3cm air space
- 14cm brick, not anchored to the inside wall. The 2 leafs are build on the concrete floor.
Since it’s a house in the row, next to this wall,there will be neighbours (house still to be build) in the future. Regulations are that there has to be a fibreglass or rockwool layer of 4cm in between 2 buildings. So the neighbours house will be freestanding.
The left wall = 9cm brick wall with a door (see sketchup picture). On the other side of that wall, the kids have their space for video gaming, playing etc. So there can be sometimes a lot of noise… I will not be recording then, but maybe listening to music or jamming...
The roof :
- beams of 18cm with fibreglass isolation in between of 18cm.
- A wind and rain shield something(polyester stuff)
- Roof-tiles (see picture in attachment "roof with window.jpg")
The inside of the roof looks like picture "Isolatie Dak.jpg"
With all this info I hope you experts can give some answers to my questions :
1) Is the right wall already a double leaf (this was done for thermal insulation, I was already aware that this was going to be a problem

2) A bit the same question about the rear and front wall of my studio. Is the roof with the beams + roof-tiles (50kg/m²) the first leaf ? So when I add say 2 layers of gypsum to the beams, this would be the second leaf of the MSM system. When I then build my room decoupled from this, I end up again with a triple leaf system? So is it best not to put gypsum on the beams, and just build my room’s wall’s say 10cm apart from it ?
Thanks in advance for the help !!
Dirk.