Buiding in wood

Hello , I finally got my building permit, and I'm planning to build a studio in my garden. I will build a basic garden shed in wood and then soundproof and do the acoustic treatment on the inside. The maximum possible outside length for my project shouldn't exceed 610 cm. For the width I could go up to 400 cm, but I will choose the width according to the best possible ratios, keeping in mind that the inside size for the room shouldn't exceed 23 square meters. In order to decide on the exact inside dimensions and room ratio, I need to figure out the total thickness of my walls, so if anyone could advice on an optimal thickness for the insulation and the shell, I would appreciate. I have neighbours at about 10 meters distance, but the building itself will not touch any construction. Also should I leave an air gap between the outer and inner shells in order to avoid sound transmission? Thank you for your help. Regards

I will build a basic garden shed in wood and then soundproof and do the acoustic treatment on the inside.

I'm not sure that's a good idea at all. A "basic garden shed" does not sound like the basis for a good studio. Garden sheds that I've seen are pretty thin and flimsy. I don't know how you'd go about isolating that successfully, without rebuilding the entire thing. It would probably be better to plan the construction properly from the start. You can easily make a good studio LOOK like a garden shed (if you really want to), without it actually BEING a garden shed.

I need to figure out the total thickness of my walls, so if anyone could advice on an optimal thickness for the insulation and the shell, I would appreciate.

In order to do that, you first need to say how much isolation you need! A simple 8 inch wall might be more than enough if you live in the middle of the desert, or you might need two feet of solid concrete if you live next to a military air base. It all depends on what you want to achieve.

Also should I leave an air gap between the outer and inner shells in order to avoid sound transmission?

basically yes, but search the forum for "MSM" and "MAM" and "two-leaf", then read all the threads you find there, and you will have your final answer! :) - Stuart -

Sorry, it's not what I meant, in my building permit application, I said I wanted to build a garden shed to make it easier, but in fact, I will actually build a proper wooden framed house. So I'm thinking of 15cm thick panels, and I will then build a room inside the room. For the inside shell I'm not sure how thick the panels should be, but I was thinking about 10cm, with a 5 cm air gap between both panels, so that would be about 30 cm in total ( 11,81 inches). Does it sound right? As I said I have neighbours about 10m away, but my studio will not touch any other building. I'm intending to play and record drums so I need fairly good isolation. Any advice or ressources for this project are welcome, I'm really at the bottom of all this now so I need guidance. Thank you

When you say "15cm thick panels" and "about 10cm panels", what type of construction materials are you referring to? About the only construction material that I can think of that you can build 10cm or 15cm thick, are brick and concrete! Those are both great sound isolators for sure, but you titled this thread "building in wood", so I'm not really understanding: Are you really planning to use solid wood panels that are six inches thick? Something like a log cabin, maybe? Or maybe 2x6 planks staked sideways? I don't understand how you'd build a solid wood wall "panel" that is 6 inches thick.

... with a 5 cm air gap between both panels,

5 cm is not enough. You need at least 10 cm of air gap, and even more if you can afford the space. Especially if you need very good isolation. On the other hand, if you really do build solid wood leaves that are 15cm thick, then 10 cm would probably be more than enough. Maybe you could use the SketchUp program to draw a diagram of what you have in mind for your wall construction. The normal way of building a studio is with a wall that consists of two "leaves". Each leaf is a large flat and massive surface, built with high density materials, such as concrete, brick, drywall (plasterboard, gypsum board), wood (MDF, HDF, plywood) or something like that, separated by an air gap. If a leaf is built with drywall, MDF, or plywood, then that needs to be supported on a stud frame of some kind. The studs can be either wood or metal. The air gap should be entirely filled with mineral wool or fiberglass insulation. The inner-leaf ceiling rests only on the inner leaf walls. the outer leaf roof rests only on the outer leaf walls. There is no contact at all between the inner leaf and outer leaf: they are two separate structures. Building like this is called "MSM" construction (Mass-Spring-Mass). the "spring" is the air in the gap between the leaves, and the "mass" on either side are the two leaves. This is a tuned system, that works something like a notch filter or a parametric equalizer: It is tuned to one specific frequency, and it PASSES sound very, very well at that frequency. It blocks sound increasingly well at frequencies greater than twice the resonant frequency. So it has to be tuned to a frequency well below the lowest frequency that you need to isolate. You tune the wall by changing the mass or the air gap, or both. The resonant frequency goes down as mass increases. The resonant frequency goes down as the air gap increases. In other words, for better isolation you need high mass in both leaves, and a large gap between them. If you do NOT need good isolation, you can reduce the mass, and reduce the air gap. - Stuart -

Ok so this is basically the principle to give you an idea: http://www.siteau-batiment.com/images/m ... bat-10.jpg