Studio design in a barn

Hi, My project is to make myself a homestudio in this barn: I have absolutly no experience in this field, what I know comes from reading Rod Gervais' book and some articles, and the information on this forum. However I wanna do this as good as possible and that's what I came here for. To get some discussion going, ask some questions and hopefully get some advice and guidance. I'm planning to record music (drum-bass-guitars-rock) in this studio as well as rehearse with my band. The rehearsing part is probably the loudest and most annoying part for the neighbours so I want to attain as much isolation as possible in my budget. I've drawn the barn in sketchup and, as a starting point put the "Small studio in 3D" from John Sayers inside the existing walls. The scaled studio fits quit nicely in this barn. The floors are bricks and stones laid on the ground. I think the existing walls are allready interesting to get some isolation. They are 30cm wide brick walls. The neighbours are at about 15 meters away. Sound sources are the railway which is fortunately not intensely used, and the road, but there's a house between the road (light traffic) and the studio. The roof is I think the biggest isolation concern: I hope this picture is detailed enough to see how the roof is built. This outer leaf that is allready there (walls + roof) is not airtight at all on the sides, and the roof is just an eternit fiber cement panel. I have talked this through with an architect and an engineer, they came to the solution of buiding a structure inside the existing walls in concrete blocks, with a concrete ceiling. This structure would be standing on a new concrete floor which does not touch the existing walls. Then building the studiovolumes inside that with metal studs and drywall. This solution is based on the problem that within my budget I can not have a new roof so every building element needs to get in by the door. Which means no large steel or wooden beams. What is your opinion on this ? Is it creating a 3-leaf wall ? Is there another budgetfriendly method that has no 3-leaf drawback ? My budget: I'd like to keep the construction plus treatment plus heating and cooling under 20.000€

on the ceiling, you might be able to put an isolation ceiling on top of the brick walls which will help there and leave the space above open for ducting etc. can you re-arrange any of the interior dividing walls?

As I understand it the plan the architect is proposing is: Building a wall with concrete blocks inside the brick walls, (he doesn't want to use the existing brick walls because of stability issues) Inside that second structure comes a metalstud structure with drywall. Leaving a gap between both walls of 17cm (6,7 inch). On top of those concrete walls comes a ceiling with a minimum weight of 360kg/m2 Underneath that ceiling comes a metalstud structure with the same drywall. @gullfo I can and I plan to completely remove the inside wall 'A' in this picture. Thanks for your ideas.

so the interior block/concrete wall and ceiling would be separate from the brick walls? that would be good. then the interior steel frame and drywall could be lightweight (single layer) (on those walls) to act as absorbers without creating a triple leaf issue. any interior walls should follow this model (block/concrete + lightweight framed skin) if possible. dampen air cavities with light (15kg/m3) insulation and use the rigid insulation inside.

Thanks Glenn,

so the interior block/concrete wall and ceiling would be separate from the brick walls?

Yes, brick wall and concrete wall are independent. The only non-air connection is through the ground. The concrete blocks are standing on a concrete slab. The concrete slab comes over the existing floor, which is bricks and stones on top of compacted earth.

Dampen air cavities with light (15kg/m3) insulation and use the rigid insulation inside.

Could you please explain a bit more ? Rockwool in space 2 ? Where does the rigid insulation come ? Maybe I should remove the bricks and stones from the floor so the concrete slab sits on the compacted earth ? Will this double wall effectively insulate the studio to a neighbour who is about ten metres further ?

if you can make the concrete/block wall sit on its own footing separately that would be good, then the interior treatment walls sit on the slab which is then decoupled and sealed from the isolation walls. in the space between the brick and concrete the light insulation will help dampen that cavity from resonances. on the inner space - if its an isolation wall - light insulation, if its a treatment wall use the rigid insulation/

Thanks Glenn. I'm still thinking about the isolation value. If we think of the brick walls as outer leaf, concrete walls as inner leaf, and the lightweight wall as absorbers/treatment. Isn't this outer leaf an acoustic leak when we look at the roof ?

yes, you're ceiling needs to be as massive or nearly as massive as your walls - if you can do reinforced concrete across the ceiling that would be good. if not, then a lightweight ceiling with drywall and joists inside on the inner concrete and another sitting on the exterior wall should suffice.

I had a meeting with the architect, and I asked him to review another plan: Inside the brick wall a supporting steel beam structure, which supports a concrete floor (without loading the brick wall). Probably more expensive?

Quick question.....If you have to build a complete concrete structure within the old building, would it not be just as cost effective to remove the old building and start from scratch?

JimDaddyO wrote:

Quick question.....If you have to build a complete concrete structure within the old building, would it not be just as cost effective to remove the old building and start from scratch?

If money is no option...sure, but money is always a pertinent part of what we do...so ...no it would not be cost effective. Think about it like it is your money you are spending, it all gets clear from that point :)

JimDaddyO wrote:

Quick question.....If you have to build a complete concrete structure within the old building, would it not be just as cost effective to remove the old building and start from scratch?

The roof stays on, that is a big difference in cost.

If you can retain the existing brick walls, create a new inner foot/slab to put the inner rooms on, that will likely be more cost effective than taking down the building and starting over. Depends on your existing footings etc. If this is an option. If not, this is where you start to balance money, time, isolation levels achieved, treatments etc.

ward wrote:

Thanks Glenn,

so the interior block/concrete wall and ceiling would be separate from the brick walls?

Yes, brick wall and concrete wall are independent. The only non-air connection is through the ground. The concrete blocks are standing on a concrete slab. The concrete slab comes over the existing floor, which is bricks and stones on top of compacted earth.

External image, not preserved — original: http://img.photobucket.com/albums/v54/perki/Studio/detailmuuropbouwgrond.png

Dampen air cavities with light (15kg/m3) insulation and use the rigid insulation inside.

Could you please explain a bit more ? Rockwool in space 2 ? Where does the rigid insulation come ? Maybe I should remove the bricks and stones from the floor so the concrete slab sits on the compacted earth ? Will this double wall effectively insulate the studio to a neighbour who is about ten metres further ?

If it hasn't already been brought up...this assembly has multiple air spaces...this is not what you want. You want one hard barrier/and air space/another hard barrier. Do not fight it.

xSpace wrote:

If it hasn't already been brought up...this assembly has multiple air spaces...this is not what you want. You want one hard barrier/and air space/another hard barrier. Do not fight it.

I am trying to get to the mass-air-mass system. Obstacles are : - the footing of the building is small, very small (we don't wan't to load the existing brick walls. - there is no ceiling, so no top on the outer leaf. - my architect wants a ceiling that can carry some weight. (if for instance someone should start using the attic to stock paper ...) Please review the other photo's and drawings, they tell the story much clearer. My english is very limited, sorry. The architect had some time to review the steel beam structure option, this is the result:

First remark, the height he specifies (2,55m (8foot37) untreated) is far too low. The brick walls are 3,50m so it's easily obtainable to keep 3m untreated space. The steel beam in the middle should be moved a bit to go in between the control and live room: Any comments about the floorplan design ?

the floor plan looks good. why does the architect think the walls are only 2.7m high?

gullfo wrote:

the floor plan looks good. why does the architect think the walls are only 2.7m high?

Beats me ?? I've made him a very detailed drawing. He probably thinks that 2.55m internal height is enough. To explain the situation a little: He's the architect for our house, he's not an acoustic expert, and doesn't claims to be. We have someone who has more expertise in acoustics who he consults from time to time. I still have to wait now to know the budget for this structure, whether it will be steel, wood or concrete block pillars with beams on it. It all depends on the cost, steel is probably the most expensive

why do you want to put heavy things on the ceiling? one option would be to add a deck with the proper support for storage so the isolation ceiling is not burdened with the support for arbitrary weights.

As you might notice there's a 5 year gap here ... :oops: things got hectic and the house came first. So where am I at right now, http://smg.photobucket.com/user/perki/slideshow/Studio/studio%202015 I have a steel reinforced concrete ceiling, 360kg/m2 the ceiling is suspended on steel beams, these steel beams are sitting on big 0.8mx0.8mx0.8m blocks of concrete underneath the original walls, The floor is at least 17cm of steel reinforced concrete. This leaves me with a height of 2,9m width of 6m length of 10m This space is now my rehearsal space for R&R-band with a LOUD drummer. Where I wanna go from here : - injection of the original brick walls against rising damp in these walls (that are filled with salts) - about 5cm PUR/PIR with aluminium layer against these brick walls, to prevent the salts from coming into the airgap. I have genelec 1032's that I'd like to use as big monitors, Emes black TV's as nearfields. I believe I wanna drop the small voice booth. I'm not confident in what I wanna do with the space, one-room recording space or live/control room. Your opinions ? One of the first thing that is mentioned in acoustic books is the room ratio, but in my original plan all inside walls are in an angle non 90 degrees. Is it possible to calculate room ratios? Is it a bad idea ? Should I go with rectangular rooms?

I'm not confident in what I wanna do with the space, one-room recording space or live/control room. Your opinions ?

You don't show any dimensions on your diagrams, so it's hard to say, but it does look like you have enough space to do a small control room and a small live room.

One of the first thing that is mentioned in acoustic books is the room ratio, but in my original plan all inside walls are in an angle non 90 degrees. Is it possible to calculate room ratios? Is it a bad idea ? Should I go with rectangular rooms?

Use one of these Room Ratio calculators to figure out the best dimensions for your room: http://www.bobgolds.com/Mode/RoomModes.htm http://amroc.andymel.eu/ Both of those are very good, and will help you to decide how best to build your room. Those calculators only provide accurate prediction for rooms that are rectangular, or close to rectangular. It's a good idea to do that, though, even if your room is not truly rectangular, as it will still give you a rough idea of how the modal response will be. - Stuart -

Thanks Stuart. I updated the plan with some dimensions. http://img.photobucket.com/albums/v54/perki/Studio/studio%202015/grondplan%20met%20maten_zpsdxjyz0wc.jpg I tried the room ratio calculators with average widths, and It seems to be ok for the control room. control room : 5.5mx4mx2.7m The live room : 5.5mx5.3mx2.7m is not ok!

There's no need to angle the walls like that. You can if you want (for example, if you are trying to do an RFZ or CID design concept), but in that case they only need to be angled as far back as the mix position. And the rear of the room should not get narrower: it should get wider, or stay the same width. - Stuart -

Thanks Stuart,

Soundman2020 wrote:

There's no need to angle the walls like that. You can if you want (for example, if you are trying to do an RFZ or CID design concept), but in that case they only need to be angled as far back as the mix position. And the rear of the room should not get narrower: it should get wider, or stay the same width.

When I poured the concrete floor I made a 2cm gap between the mixing room and the live room. I did this in the diamond shape like in the drawing 2 posts up. This was done to avoid crosstalk. Would you prefer to make the rooms completely rectangular and ditch the existing gap in the floor ? I was also trying to minimize flutter reflections, possibly out of a lack of real knowledge? Reading another thread in which you commented:

From "Small Studio in Finland" thread: You are wasting space by splaying the complete side walls like that. You only need to splay (angle) a small part at the front of the room, roughly as far back as the mix position. From there to the back, the walls can be parallel, to increase the total volume of the room. If you end up with flutter echo problems like that, then it's easy to treat those with absorption panels on the walls (and you will probably need those in any event). The same problem happens with the way you are cutting off the rear corners of the room. That wastes space, and those corners are where your bass traps need to go.

When I poured the concrete floor I made a 2cm gap between the mixing room and the live room.

Hmmmm... that's a problem! It means that you are locked into those shapes and dimensions now. You have three options: 1) Use them as they are, with the CR shape not being optimal. 2) Modify them by cutting the slab in some places, and filling it in in other places. 3) Ignore them, and build any place you need to, but losing the advantage of the decoupling. But first, there's a question: Did you leave a gap ONLY between the LR and CR? Or did you also leave gaps all around the edges of both slabs, such that they do not touch the walls? In other words, are your walls resting on a separate foundation from the slabs?

I was also trying to minimize flutter reflections, possibly out of a lack of real knowledge?

Flutter echo is fairly simple to deal with, using basic absorption panels at strategic locations, or diffusion in some cases. And since you will need that anyway, there's no need to splay the walls as well. The only real reason for splaying walls is if you want to build an RFZ-style studio, or one of the similar types, where the room shape itself is used to direct sound away from the mix position. Or you might just want to do it because it looks good! :) - Stuart -