Single Room 5.4mx3.2mx3m Need Some Advice at Concept Stage

[scottkrk]

Hi,

My name is Scott, I live in Sydney Australia. I have been a member on the site for a few years, many thanks to all the contributors, I have learnt a lot but I am also aware of how little I know. I am finally ready to bite the bullet and explore building a home studio and would like some advice/guidance at the early concept stage.

My Current Situation and Issue

• My home studio is currently set up in a room in the house (see image below)

• Inspiration usually strikes in the evening but because I have no isolation, I have to be very quite not to wake up the family.

• I want to be able to record vocals, acoustic/electric guitar and playback/mix at around 90dB SPL in the evenings.

Current Studio.jpg

The Home Studio I would Like to Have

• Single control room

• Room within a room 2 leaf system for approximately 50dB of isolation. (Is this enough if the neighbours buildings are more than 10 metres from the studio?)

• Best treatment I can afford including Soffit mounting, bass traps, resonators, clouds and diffusers, as illustrated in John's small studio design below

John Sayer Design.jpg

Exploring the Option of Building Home Studio in a Detached Shed/Cabin/Granny Flat

• My home studio is directly below the bedrooms so I would never have enough isolation if I tried to build in the house.

• The Australian State I live in allows me to build a separate structure on my property that won't need a DA or council approval if it meets the following requirements. 1. Must be no greater than 20m (squared). 2. Less than 3m in height. 3. At least 0.9m from a boundary.

• Various companies offer these 'pre-approved' structures in my state.

Specifics of the Structure I am Considering

• The external dimensions are Length 5.4m x Width 3.2m x Height 3m in the centre and 2.1m at the wall.

Dimensions.jpg

• I would have double doors at one end, single high window at the other end and no windows or doors on the 5.4m sides

• Below are images showing the type of construction, the cost is approx $15k installed.

Internal.jpg

Exterior.jpg

Footing.jpg

Some very Broad Questions

• Is this kind off structure and footing suitable as the 'outer shell'?

• Given a room within a room approach approximately how much space will I lose, particularly height?

• Are these dimensions workable/desirable from an acoustic ratios perspective, I assume the main way you 'tune' it, is by varying the depth of the internal 5.4m wall, as there is not much room to play with on the 3.2m width and (3m-2.1m) height?

• What have I missed on my cost check list below?

• What have I missed on my next steps list?

• Has anyone used one of these 'shed' companies in NSW or ACT? Any good news or horror stories?

Cost Check List
Given that I can't design or build, about the only thing I can do is solder audio cables, I will have to hire a professional:

• Studio Designer

• Studio Builder/Carpenter for interiors

• Electrician

• Air Conditioning/ ventilation installer

Next Steps

• Contact studio designers

• Find Studio Builder/Carpenter

• Finalise a concept with studio designer/studio builder/shed builder

• Work out budget. Anyone like to hazard a guess in AUD$

• Move to detailed design, build, test and commission

Any answers/perspectives on the questions, costs and next steps would be greatly appreciated, as would any advice on how to find and contact studio designers and builders.

Cheers,
Scott

[Soundman2020]

Hi Scott, and Welcome!!!!

I want to be able to record vocals, acoustic/electric guitar and playback/mix at around 90dB SPL in the evenings. ... Room within a room 2 leaf system for approximately 50dB of isolation.

That's a very reasonable goal for a home studio, and very much do-able.

Is this enough if the neighbours buildings are more than 10 metres from the studio?

It should be, yes. If you do get 50 dB of isolation, you'd be at 40 dB just outside your wall, so you'd be down to the low 30's at that distance, which is practically inaudible, especially in a residential setting. You also have no drums, bass or other very low frequencies, so I'd say that they'll never hear a thing.

Best treatment I can afford including Soffit mounting, bass traps, resonators, clouds and diffusers,

With a room that size, "all of the above" should be possible, perhaps with the exception of the diffusers (depend on room geometry, type of diffuser, and diffuser tuning.

1. Must be no greater than 20m (squared). 2. Less than 3m in height. 3. At least 0.9m from a boundary.

That's pretty neat! I wish we had regulations like that here.... You can do a good studio for what you want, within those boundaries.

Various companies offer these 'pre-approved' structures in my state.

That's probably not the best way to go. Those are not designed to be used as well isolated acoustic studios: the amount of modification you'd need to do to one of those in order to make it usable for what you want, is pretty significant.

I would have double doors at one end

Double doors are a problem for any studio that needs high isolation. The issue is simple: How do you create the type of seal that is needed, where the two doors meet? That's a tough problem to solve... In order to get high isolation you do need a perfect seal all around the perimeter of the door, and that's hard enough to achieve even with a normal single door. But with two doors that meet in the middle, that's a whole lot tougher. I've heard of many home builders proposing to do that, but to be brutally honest, I've never heard of anyone being successful. I may be wrong on that, and maybe someone has done it, but I have a feeling that if you managed to pull it off, you'd be the first. Sliding glass doors are not a problem (but they aren't "double doors" in the sense you are talking about), so you could do that if you want. But not doors that swing open on hinges.

So I'd suggest just going with a conventional single door. Make it big if you need a wide path for load-in and load-out, but keep it single.

Below are images showing the type of construction,

A wooden floor? Over an air space? Not if you need good isolation...

Is this kind off structure and footing suitable as the 'outer shell'?

No. Not really. It is too flimsy, and not designed to take the type of structural load you'd be placing on it, by building your inner-leaf inside it, and that's without even considering the weight of the treatment, HVAC and gear. I'd check the specs on those sheds, to see what type of additional loading the floor can handle, but I'm pretty sure it is way less than what you'd need.

Given a room within a room approach approximately how much space will I lose, particularly height?

Assuming typical construction, you'd lose about 10 to 15 cm on each side, and more for the ceiling. How much you lose up there depends on several factors, but mainly the distance you need your joists to span, and the amount of load you'd be putting on the. It won't be less than 15cm, and could be substantially more. 25cm is possible. So 2.1m is probably much too low for what you need. It would be down to about 1.9m, just from the structure, then you'd need your cloud, or some other type of treatment, which could take out quite a bit more headroom.

Are these dimensions workable/desirable from an acoustic ratios perspective,

That's hard to answer, without knowing what the actual inner-leaf dimensions are going to be. Once you figure those out, you can use one of the standard room-more calculators to see what kind of results you get, then tweak your dimensions as need to get a better ratio, if that turns out to be necessary.

What have I missed on my cost check list below?

Ummm... Materials? I don't see any building materials on your list. That will be one of your three main expenses (the other two being labor and HVAC/electrical). You might also need a structural engineer, or architect: Even though you don't need planning permission, you might still need some type of inspection along the way, especially with the electrical work and structural work, so I would check your local building code in detail to find out if there may be expenses like that, that you had not considered.

The rest looks like a reasonable basic plan, but rest assured, your lists will grow as you progress! It always does.... And so does your budget... But it looks like you have the right basic idea.

- Stuart -

[scottkrk]

Stuart,

Many thanks for your detailed response.

If I understand correctly the key messages are:

• I am better of being directly on the ground (presumably a slab?) for isolation

• Better to go with a custom build on the 'shell', rather than try and repurpose a shed.

• My isolation and good acoustic/ treatment goals are achievable in the 60 cubic metre restrictions of my State's 'no approval' building restrictions

Sorry for rephrasing and asking for confirmation but I just want to make sure I am following you correctly.

Many thanks,
Scott

[Soundman2020]

I am better of being directly on the ground (presumably a slab?) for isolation

Correct!

Better to go with a custom build on the 'shell', rather than try and repurpose a shed.

Correct!

My isolation and good acoustic/ treatment goals are achievable in the 60 cubic metre restrictions of my State's 'no approval' building restrictions

Correct!

Yup. You got it on all three.

Sorry for rephrasing and asking for confirmation but I just want to make sure I am following you correctly.

No problem at all, and that's actually very smart to double-check. I wish more people would do that! Every know and then we see folks who didn't do that, then ended up having to take things apart and re-build them, when they discovered that they hadn't understood something correctly. So please feel free to ask as much as you want!

After all, that's what the forum is here for...


- Stuart -