Help understanding "Inside Out" walls

Like the title says, I'm researching the idea of using 'inside out' wall construction for my studio build. There are A LOT of factors for starting any business, and I'm in the process of writing a business plan, as well as scouting locations and drawing up designs, etc... In other words, I don't have any specific designs just yet; I'm just trying to decide which construction techniques make best use of my budget. But, for sake of discussion, here's some basic dimensions/rooms I'm thinking about (all dimensions in feet): Control Room: 10H x 12.6W x 15.9L Live Room: 10H x 16W x 23.3L Iso Booth: 8H x 9.12W x 11.12L Proposed Budget: $25,000USD (the more I read this forum, the more I realize how little this is, sadly :? ) Ok, so the "inside out" wall makes sense in theory. Flip the wall around and the insulation in between the stud cavities now acts as an acoustic absorber. Cover with fabric and slap on some nice wood trim, and I got myself a nice, albeit 'dead', space. The same can be said for the ceilings as well; I suppose it depends on the ceiling height of the existing structure. I.e., securing a few layers of drywall to the TOP of the ceiling seems impossible if the building is only 11', and my rooms are 10'. But I digress... In any event, lets say I wanted to utilize this technique for all the rooms of my studio. How much air space is needed in between each leaf for the walls to approach the same TL as a traditional double-stud wall? 6"? 12"? Next question (for now), let's assume I constructed the Live Room in the "inside out" fashion, but found acoustically it's just too dead. If I added sheets of say, plywood (fabric covered or painted/finished)) would that act as another leaf? If I go this route I thought about just doing slats over the stud/insulation cavities, but with my limited budget, I may not have that option. TIA! -Dan

welcome! adding the slats will provide by HF support as well as broadband (assuming the right slat/slot combinations). yes, by its nature there must be some third leaf effect but there is also significant absorption and diffusion. plus adding plastic under the cloth will help. ultimately your design and build will ultimately be site specific but as a general rule - consider the cost per unit area for a high end home in the location you intend to build, add 25% or so. deduct 30% if you're doing all the work. so if you have 250ft2 space and it's $100/ft2 (after deducting DIY %) and you are looking at $25K for construction. then factor in equipments etc etc. what can you do with 250ft2? (or maybe half that if the cost is $200/ft2) then determine how that matches your business plan: live recordings of 20 piece jazz bands etc versus an acoustic guitar or single vox, etc to ensure there is strong alignment with your budget planning and your business goals.

Glenn, thanks for the reply and the welcome! After a bit more reading, I've come to the conclusion that using Inside Out walls isn't worth it. I may do it for the Iso Booth to save a bit on materials though. I'd rather spend the extra cash and do the double stud walls the traditional way. As for your cost per SF estimates, is that for a building from the ground up? I ask, because I've been working on a materials estimator excel sheet, and I'm around the $45/sf mark, including labor and HVAC. Granted, I have pretty modest needs and wants, but I'm doing everything the right way. I'm just saving on the finishing and going budget minded (laminate floors, DIY diffusers, etc...) I've gotten labor quotes from people I know and trust; not sweetheart deals mind you, but they're fair I feel. For example, my contractor said he'd charge me $425/day to get all the important things done and up to code (framing, hanging drywall, electical, etc...) and suggested I do all the finishing work myself. For the size studio I'm doing (600SF, give or take), he figured about a month from start to finish. Bare in mind, the spaces I've looked at so far have very minimal demolition work and all are on ground level concrete slabs. But those are requirements I've had my real estate agent scouting for me. I know I'm going a bit off topic, I'm just curious what I'm missing because my estimates are VERY low compared to what seems to be the norm amongst you fellas here suggest. Either way, I really appreciate what this forum has to offer. Knock on wood, I'll be getting this project off the ground very soon!

Hi guys, May I take this opportunity to post my first reply? I'm a new member but have been researching this incredible forum for some time. (I'm new to forums in general so apologies if ask / do anything stupid or out of line with forum etiquette!) I'll soon be posting further details of my proposed studio design according to the forum guidelines, but having come across this thread, have a question specifically about inside out walls. It is important to me that my live room is 'live', and so I plan to plasterboard the inside wall of the live room (as well as other treaments). However, I also want to exploit the absorption benefits of having insulation on the inner side of the control room wall. Consequently, I was wondering whether the following double-leaf structure is possible; (from control room side) Insulation in studwork -> 2 x 15mm plasterboard -> 200mm air gap -> insulation in studwork -> 2 x 15mm plasterboard Would there be a drop in STC compared to the typical STC 63 wall struture (plasterboard on outside face of each wall)? Would sympathetic resonance between the two leaves be increased? Many thanks in advance, Russ

your ideas works - it's still a double leaf and any calculations for MSM are still effectively the same - you are simply reducing the air space around 100mm in exchange for building in wall absorption in the CR.