I'm so stoked! I just got my order of Roxul 80 insulation and built panels to put where my sliding glass door and my windows are, to keep the outside noise down. I put my normal recording setup at normal levels, and all of a sudden the garbage truck comes right down the street with the back up alarms on, and I think they must be getting ready for an air show because loud ass planes have been flying over all day! But my meter never peaked above -60dbfs with all that (used to peak about -18, real problem once you start compressing). Yay. So just some inspiration if you have trouble from windows in your recording space, might want to check this stuff out!

http://www.amazon.com/gp/product/B006C10IR6/ref=ox_ya_os_product_refresh_T1

 

Not sure if this is exactly the same material, but used to use same kind of boards (only 4 inch thick) while designing & building studio acoustics.
Helmholtz resonators and traps.
Really efficient yes and fire proof

http://www.google.fi/search?num=100&nord=1&site=webhp&q=helmholtz+resonator&oq=helmholtz&gs_l=serp.1.2.0l10.18548.20029.0.23402.2.1.0.1.1.0.67.67.1.1.0....0...1c.1.44.serp..0.2.75.sWPirZ6_6gM

 

Things like a truck have low frequencies so the sound is propeled by hard material.
Sorry but requires mass (probably the same of a truck), probably a floating floor...
Edit
I remember that a must is rock wool (I have 2 enermous in ther corners) and it also helps to record real large drums..

 

Yeah, I guess I should mention that I had a HPF on the pre... I can definitely still hear the low rumbles from the road outside, but since the only thing I record without a HPF would be a kick drum or a bass amp, both of which would be close micd, it's not really a problem for my setup. And this stuff definitely kills the frequencies that interfere with the things I'm recording (vocals and acoustic instruments). And yeah, Roxul is rock wool.

 

I have a friend that puts signs in his yard to prevent outside noise. Like "Newborn Sleeping", "recording studio, be courteous".
All my neighbors are old people so I dont have to worry about noise lol.

 

this is acoustic treatment not soundproofing soundproofing requirements construction

 

No this is soundproofing. Acoustic treatment is intended to improve the sound of things inside the room. Soundproofing is meant to block sound from outside the room, or to prevent sounds from inside the room from getting out. I put the panels up to block sound from outside, which they did, albeit (obviously) not nearly as well as isolating construction would do. But it is still soundproofing. In fact, part of the construction process you refer to would involve putting some sort of insulation like this in the walls. And then probably some isolating sheeting, and then building out on isolators.