As someone here said, "sound easily bypasses the walls through cracks and windows". The spray foam is harder to install wrong, preventing gaps or voids through which the sound will travel. That is why - regardless of tests of materials - spray foam walls are very quiet. Same for ICF walls (which also have the advantage of foam on outside absorbing sound energy and what gets through the wall doesn't radiate well from the foam. After quality sealing with the foam insulation and quality well sealed windows with at least double glazing, de-coupling is the key. You want to minimize direct transmission paths and isolate materials that transmit sound well. Outside: Whatever your outer wall is, the sheathing get modulated with vibration energy from sound energy. To stop sound at this "origin", you can spray the sheathing with one or two inches of closed cell spray insulation, covering everything except intentional openings and the furring; this has an astounding improvement on the thermal efficiency of the wall as well, as the heat absorbing outer surface is insulated it will perform far better than the resulting R value would suggest. The wall siding goes on the furring (sized to allow for the spray foam), which goes in place before the spray form goes on. Also, cut a long strip of sill plate gasket (foam strip, 1/4" thick) and staple on the sheathing where the furring goes. Depending on the siding going on the furring, another strip of sill plate gasket on the furring first. These are two thermal/acoustic isolators between the siding and the sheathing. A bead of acoustic seal on the outside of the studs and plates before putting the sheathing on also seals the space. Inside: Staggered studs mean that the studs are not direct energy transmission paths (thermal or acoustic) from the sheathing to the drywall. The studs will still receive energy from the plates, but this greatly reduces the area/cross section for transmission. Now the drywall, which will be your sound radiating "speaker" surface, needs to be decoupled from the studs. There are rubber o-ring style washers that can be used to do this; difficult to use. Where I am, we vapor seal on the inside, so I'll include that. A bead of acoustic seal on the inside surface of the studs and plates (to seal the resulting "panel" between two studs, acoustic seal the seam between the stud and plate), then install the vapor barrier. Another bead of acoustic seal, then a sill plate gasket on the studs and plates. Another bead of acoustic seal, then you install the drywall. The sound has trouble transmitting through the energy absorbing mediums. For more isolation, do the acoustic seal and sill plate gasket as above, then install furring on the inside of the wall to mount the drywall. The furring is isolated from the plates were the studs aren't. Of course, acoustic seal and sill plate gasket to the furring before mounting drywall. This creates a decoupled wall. You want to up it from there, you can find a rubberized spray and coat the back side of your drywall before installing it. But, unless you've got amazing sound proofed, windows, you'll never notice the difference with this. The thermal energy performance of this wall is amazing. Why the little extra acoustic seal to make sealed panels? No gaps for sound in air to penetrate, and, no paths for flame. The panels are now non-vented panels. The only way for fire transmission is for a complete burn through. Energy in the structure will vibrate ceilings too. Don't for get to install acoustic seal and sill plate gasket for the ceiling drywall. There are more complex and thicker wall systems with completely de-coupled inner walls with an air gap between them, but you lose inside space and the cost goes up again. I'd highly recommend the following combination: 1. outside furring (with sill plate gasket between furring and sheathing) with closed cell spray foam; 2. closed cell spray foam insulation; if you need to save some money, then one to two inches of closed cell spray form on inside of sheathing - balance to fill cavity can be open cell foam (cheaper) or the insulation of your choice; 3. staggered stud walls, six inch wide plates (six inch "interior" for insulation); 4. sill plate gasket with acoustic seal on studs and plates. With two inches of foam on the outside, the nominal R value is higher than R34, but the performance is closer to R50. You could use a four inch wall/plate and get R40 performance, but now you're using non-standard sized materials and introduced structural questions. You'll love the thermal comfort and savings along with the peaceful interior. Modeling suggests a home like this, along with quality vinyl double-glazed two-way low-E inert gas windows, will use 1/3 the heating/cooling energy of a R2000 home.

This is just my opinion: I'd only consider a garden window IF: - I lived in a COLD climate, and -the window faced south or maybe west, and -it did not take away from the architectural style of my home and... -most importantly, I was actually going to use it to grow herbs in the winter, etc.! (A neighbor has one, but has stupid fake flowers & little figurines in it. Tacky.) When I lived in NYC, I would have LOVED one, as I loved having houseplants and kitchen herbs in a sunny window. But here in sunny SoCalif, I wouldn't haveÂor wantÂone, though plenty of people do. Ironically, I seldom see REAL plants in them. So, go figure. I also don't really like the boxy-ness of them, but that is a personal thing. As brushwork said: make sure it is quality all around. good luck!

ick... casement windows are such a pain, I've had them in 2 homes and finally replaced them all in current coatal small home. Everythng is expensive and diffficult to repair and fix with casements ex hinges and weather stripping, not to mention the screens are on the inside which no one in the South will tolerate year round. The interior crank handles get in the way of all window treatments. They are leaky windows. Once they have been painted once the weather stripping is gone because it is hard to convince painters not to paint the bulb type weather stripping .... very out of date window style ...unless you live in New England and can keep your windows open half the year ...

7'3" is pretty big for a casement. When open, that size sash would put a lot of pressure on the hinges & operator. If you are leaning toward casements, and don't mind tearing the old frames back to the studs, then you might want to consider casements with transoms. Most manufacturers have the ability to provide detailed drawings of window combinations, so experiment with styles that might interest you.