Small studio, shoebox vs splayed walls

[Sick Astley]

I've attached an image, would you suggest the blue or the pink dimension?

The pink line is with 90° angles
The blue line is with splayed walls, that would be of no extra cost and would gain a proportion of room volume. I just don't know if the benefit of that small room volume gain would be outweighed by having a back wall that is not parallel to the front..

I based the dimensions on 1:1.25:1.6. Although the room is small it will have problems I gathered I kay as well still use the format for dimensions anyway? (Must be better than just random dimensions whatever the room volume right?)

I had another thread, but thought it would make sense to simplify with the image. Sorry if that is not the right thing!!

I have a max budget of 9 sqm for a new build garden room. The image is for internal space. It will be a control room / production room only.

It will be the same cost whichever I do.

Attached sketch of dimensions or here if it's not https://ibb.co/Dtz5H7X

[DanDan]

You could splay the side wall, which would prevent flutter echo. Bigger is better.
I see no purpose to splaying the Front Wall, presuming you will have massive back wall absorption.
DD

[Sick Astley]

Thanks,

I was thinking if I splay the front wall I then have equal left and right walls, that both come away from the front wall at +6° angles. The ceiling would also angle slightly up from front to back, although this is mainly for water run off so it would only be a difference of around 5cm front to back.

The back wall would need one 90° angle mainly so the building would seem square if viewed from the house

[DanDan]

Aaah, that makes sense. Might be worth considering increasing the ceiling angle.
As a room gets treated, anomalies start to pop out of hiding. Slap and Flutter Echoes can be very vivid in a partially treated room.
DD

[Sick Astley]

Unfortunately I'm limited on ceiling height by local permitted development, so I can't lower the lowest point anymore.

With regards to dimensions, I have based it on 1:1.25:1.6, I could go slightly narrower and longer room to allow at least some of the length to do something, but gathered I should at least follow some sort of rule even with such a small room..

(I could work with as narrow as 2.3 meters, it would give me a tiny bit extra for front and back treatment but would then eat a little into the 1st L/R reflection treatment points.

Edit:
Also I appreciate the help with a pretty lame sketch attached... I'll do one in much more detail for the actual treatment, for now I'm getting the basic dimensions set so I can get the ball rolling on the build

[DanDan]

You sure about that? We are allowed up to 4Metres for a A roof here.
I wouldn't sweat the dimensions, prioritise as big as possible.
Modes and other LF reflections will in general be stronger with brick building.
Wood frame building can provide just as much isolation but with a slightly 'limp bag' aspect at LF.
More so here, but you get rain too. This can be very very audible on a roof.
DD

[Sick Astley]

Its within 2m of a boundary so the max height is 2.5m external roof height. Which limits the internal to around 213-220cm.

I looked at lowering the ground but it's a garden room type build so it's not really an option.

The most space I would get would be with splayed walls. I think I will go with the equal front / left right walls and treat the back wall a lot... still a lot to plan in that sense but I'm getting that whatever i do, focus on maxing the space.... I'm limited to 9sqm due to cost so the splayed wall would give me a small amount of extra space, not less...

Cheers for the help!
I'll get a better plan going for the actual treatment, which I know will not be ideal, but much better than the space I have previously used!

[Soundman2020]

Unfortunately I'm limited on ceiling height by local permitted development,

Permitted Development rules in the UK, under Class E, allow you up to 3m at the peak of the roof, as long as you are not within a certain distance of the property line. The eaves can't be higher than 2.5m, but the peak can.

Also, note carefully that this is all relative to the original ground surface: there's nothing to stop you digging a hole and putting your floor a half meter lower than ground level...

With regards to dimensions, I have based it on 1:1.25:1.6

Forget that. With a very tiny room, you will have terrible modal problems anyway, so there's no point trying to nudge dimensions around a few cm here and there to get a "better" modal spread. That's like re-arranging the deck chairs on the Titanic. Not useful at all. What you need, is maximum air volume within the room: With such a very, very tiny room, every little bit of extra volume matters, and extra floor area too. Those are far more important than room ratios for a tiny room.

I could go slightly narrower and longer room to allow at least some of the length to do something, but gathered I should at least follow some sort of rule even with such a small room..

If you CAN go longer, then go longer! But don't go narrower: keep the width as large as possible, and also make the length as large as possible, and the height too.

I could work with as narrow as 2.3 meters,

Don't do that! Do not reduce ANY of your dimensions! Rather, increase all of them as much as you possibly can.

You could splay the side wall, which would prevent flutter echo. Bigger is better.

Splaying the side walls is an option, yes, but keep the room symmetrical! Symmetry is far more critical than worrying about flutter echo. You can fix flutter echo with simple panels on the side walls, which you will need in any case, regardless of whether or not the walls are splayed. So if splaying can get you a bigger room (more volume), then do it, but do it symmetrically. And if NOT splaying would get you even more room volume, then do that instead.

Your number one priority here is room volume, and number two is very close behind: symmetry.

- Stuart -

[Sick Astley]

Thanks,
It would be within 2m of the boundary so the overall height is restricted to 2.5m unfortunately, unless I requested planning permission for a dual pitched roof, but the area I live in has further restrictions beyond normal development.
With regards to digging down, the build is on feet, so I think it would be complicated to drop it, due to steps needed and possible damp problems. Something to consider though..

Re size, I literally am limited to the 9sqm whatever I do, so to get length I would have to cut back on width, however the splayed wall would be a freebie extra bit of space, so as long as I do the splayed wall as symmetrical as possible I'd get the best of both worlds.

Thanks for the tips both!