It's been quite a while since I last posted, but as we've finally moved into our new house I've been able to make some progress on the design.
That's great news, Gareth! Glad that you finally managed to move in to the new place.
(3.22m wide, 5.29m long, 2.3m high). I have decided not to bother putting a toilet and lobby area in to the building, for several reasons, so the design is now more straightforward.
Excellent! So the entire building will be your studio, no space taken up by anything else. That gives you about 17m2 slab footprint, so you'll need to work carefully to make the best possible use of that space.
The whole building will be sunk into the ground so that the top of the concrete block is 350mm below ground level. This will give me enough head height whilst staying within the permitted development rules. The highest part of the building (the front) will be 2.4m about ground.
Here's one like that, that I designed several years ago:
This one is a bit deeper than yours, and it has several steps outside the building that descend down to the floor level, but the same basic idea: Dig a big hole, put a slab in it, then build walls on it.
If not it’ll be taking a mini digger through the house and hiring some builders with a narrow wheelbarrow!
Some diggers are quite narrow, and should be able to get through. Some even have wheels or tracks that can be sort of "retracted" inwards to get them through tight spaces, then "extended" out again for better stability during the actual work. Here's a tracked one I have seen that can get through a standard doorway:
a raised floor for the rear of the studio which I'm hoping can be used as an absorber as well as a seating area itself
That can be done, absolutely, and it is a good idea of you have enough head room. It should be designed with acoustics in mind, as you already figured out: You don't want a bunch of resonant cavities down there, all singing along with your music!
Perhaps once the room is built and I start measuring, this raised floor could be designed to deal with a problematic frequency.
It's better to design it as part of the basic treatment. It can be "tuned" broadly, to treat the modal issues, along with being general "bass trapping" for the low end. The tuning is broad enough that it won't really matter if the actual issues are slightly off from prediction.
I'm hoping that if the front is fabric covered, and the triangles at the back are open to the rear wall treatment, then it won't act as some ridiculous bass boosting box.
It's a little more complex than that, unfortunately! In fact, a long "pipe" open at both ends can, indeed, be resonant.... that's the way that many musical instruments are made! Wind instruments are basically a long pipe, open at both ends...
I'm thinking your riser could also be shaped more creatively, to look nicer and also be functional, from the point of view of access to the room, and also from the acoustic point of view. Here's one with an elliptical curve shape, in a room that is currently under construction. (Actually it is pretty much finished: in the process of final tuning right now). This was taken a while back, and the second one more recently:
And here's another one, from a smaller room, with a more angular look to it, just before the deck and flooring goes on:
At this point I'm directing questions to my family friend architect about the design of the foundations,
Since you don't have any plumbing or sewer any more, now that you have dropped the idea of a bathroom, I'd suggest a simple monolithic slab would do the trick: Simple to design, and simple to build.
Looking forward to seeing progress on this! Good prospects...
- Stuart -