Would like advice for Brooklyn Commercial Loft Buildout

[rosestudios]

Hey all, first post here.

I've studied up a bit on acoustics and I have Rod Gervais' book for reference, I've previously built out walls to great effect.

I'm looking at purchasing some commercial lofts in Greenpoint, see the attached links for the floors plans of the two units. I plan to occupy 314 first and then 313 later. The problem is, these are above ground level and there's no concrete foundation between each of the floors. However they are commercial noise zoned and ready for studio installation.

What would your estimate be for a 80-90 dB of noise reduction? I'm hoping to have a control room and live room in each unit with enough space to track live bands. I know that I will probably have to float a room and that that usually involves an assessment by the building's structural engineer. What are your thoughts on this, have you encountered this situation in NYC before, and what kind of budget range should I expect to enter into this with? I would really appreciate your consultations. I just want to know if this is tenable.

There are also two similar units on the first floor but the building is near a sewage treatment plant and so there are possible threats of sewage flooding due to the increase in tropical storm intensity (see: Sandy). It may not even qualify for flood insurance.

Unit 313: http://greenpointlofts.com/pdf/313.pdf

Unit 314: http://greenpointlofts.com/pdf/314.pdf

Thank you very much, if there are any other questions I need to answer I'd be glad to, really appreciate the help, I don't want to make a large investment into a space that won't be useable.

[Soundman2020]

Hi "rosestudios". Please read the forum rules for posting (click here). You seem to be missing a couple of things!

That said, isolating a studio to 90 dB is really, really hard to do. And I mean REALLY hard! The very best isolated studio on this planet only managed to get 100 dB of isolation, and it cost them several million dollars to do that (that is "Galaxy", in Belgium). 80 dB is within the realms of reality (barely), but for upper floors in a commercial loft? Not gonna happen. Once again, really, really hard to do, and really expensive. You probably do not want to go there, unless you have very deep pockets and no alternatives at all.

Realistically, you can expect to get 50 dB fairly easily, 60 dB is possible, and 70 dB is at the fringe edge of what can be achieved. But all of those assume a "slab-on-grade" ground-floor studio. As soon as you go to upper floors, you make your job exponentially harder (and more expensive).

I guess the basic question here is: Why do you need so much isolation?

I know that I will probably have to float a room and that that usually involves an assessment by the building's structural engineer.

Yes, most definitely, to both of those points! If you really do need 90 dB, then you have no choice. Major structural modifications are in your future...

There's an interesting thread here on the forum about floating floors (also applies to entire rooms): http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173

what kind of budget range should I expect to enter into this with?

Let me answer that indirectly: The decibel scale is logarithmic, based on powers of ten. A typical house wall (a 2x4 stud frame with 1/2" drywall on each side) gets you about 30 dB of isolation. Building a better wall that gets 40 dB means you have to block ten times as much energy as that typical house wall. Getting 50 dB means blocking "ten times more than the ten times more", or one hundred times more energy than a house wall. 60 dB = one thousands times. 70 dB = ten thousand times. 80 dB = a hundred thousand times. And to get 90 dB of isolation, it is indeed, one million times more energy that you have to block, making it one million times harder to do. Shocking, unbelievable, but true. That's the reason why it is prohibitively expensive to attain high levels of isolation, since things become exponentially more costly and difficult. The tiny air gap under the door in your 30 dB house wall makes practically no difference at all, but the same crack is a major disaster for even a 60 dB room. Fora 90 dB room, you can't even afford to have the shadow of a hint of a crack! All doors require multiple independent seals, huge amounts of mass, and automatic hydraulic door closers.

To put this even more in perspective, there's a law of physics called "Mass Law", which basically says that each time you double the total weight (mass) of a wall, you get about 6 dB of extra isolation. Going from 30 dB to 90 dB, you need to double the mass, then double it again, then again, then again, then again... ten times over you need to double it. So if your original wall weighed 3 pounds per square foot (typical for a house wall), you need to do 3x2x2x2x2x2x2x2x2x2X2 = 3072 pounds per square foot. Let's say your wall is 8 feet high and ten feet long: it will weight 8 x 10 x 3072 = 245,760 pounds, or roughly the same as a fully-loaded 767! How many walls do you need?

OK, so there are better ways of getting good isolation without falling victim to Mass Law, but the point remains: you still need huge amounts of mass to get high levels of isolation. The rooms at Galaxy are double solid concrete shells, weigh hundreds of tons each, and are supported on a very complex system of springs and isolators. That's probably not what you had in mind!

So if I were you, I'd reconsider the reasons behind your conclusion that you need 90 dB of isolation, and maybe try to relax your requirements a bit. There aren't many reasons I can think of why a studio in NY would need 90 dB of isolation.


- Stuart -

[rosestudios]

Hey, not sure what else I would need to include except for my budget, which is what I'm primarily asking about?

I would basically like to track drums, as I mentioned with recording live bands in my original post, and the space is zoned for 60 dB. How can I obtain this on this upper level? Would it be recommended and simpler to order a large custom isoroom? I wouldn't have a live room sound but I would obtain the isolation I need without collapsing the loft into itself!

[Soundman2020]

Click on the link I provided, and read the part in big blue letters, about half way down the page....


- Stuart -