To add to the other answers let me share some practical ideas I have learned over the years from the days when I used to build homes and build out office space. These ideas will help you reduce considerably reduce the volume of any sound transmitted outside of your practice space, regardless of where you set it up.
Sound travels through the air. It dissipates with distance. Obviously the farther you are from a neighbor, the less problem you have with them hearing your 2 AM practice sessions. A home that is a long way from the nearest neighbor is ideal. Of course you might not want to live in the boondocks.
With attached housing (such as in a condo or townhome) where you have common walls, or in a neighborhood of detached homes where the homes are close together - you obviously have less distance. But let's examine how sound travels through walls in order to understand how to mitigate it.
The sound vibrations actually hit a wall and set up vibrations in the wall at the same frequency. These vibrations transmit the sound to the other side of the wall. The ability of any particular wall to transmit sound to the other side of it are dependent upon the material the wall is constructed of (as well as other factors).
Not all the sound will go through the wall. Some will reflect back and some could be absorbed by the material in the wall. One way to reduce the amount of sound transmitted through a wall is to create a gap between two sides of the wall. In other words - a typical wall in a home will consist of wood or metal studs with drywall (sheetrock is a common brand) attached to both sides of the studs. If you instead attach the drywall to different studs, less sound is transmitted by the studs from the drywall in one room to the drywall in the other room. In other words you need an air space where there are no common studs between the two layers of drywall so the studs themselves no longer serve as a conduit to help pass the sound from one side of a wall to the other.
Two things that can reduce the sound transmitted through a wall are reflection and absorption. The stiffer the wall - the less it will vibrate and therefore the less it will tend to transmit sound to the other side. Concrete or hard tile for example will tend to reflect more sound than it allows to pass through it. That's why in a garage with a concrete floor or a room with a tile floor and no rug, the sound echos back so readily.
If you had a home with a basement, the concrete walls would reflect far more sound than they allowed to pass through and any underground portion of the basement would not allow any transmission through the wall itself because if any did pass through the concrete wall it would be absorbed by the earth on the other side.
Absorption can also reduce the amount of sound that passes through a wall or reflects back off of it. The reason it is quieter in a room with stuffed furniture, heavy curtains and rugs or carpeting - is that all of those soft surfaces tend to absorb some of the sound waves.
You can add insulation inside a wall (or between a floor and ceiling) to help absorb some of the sound. Also you can line the walls with something that will help absorb some of the sound - such as acoustical foam sold for use in recording studios. It not only reduces reflection, it will also reduces transmission through any wall to which it is affixed.
Acoustic Foam Panel.
To reduce transmission from a common wall or outside wall to your neighbor next door, you can build a second wall (ideally with no windows but beware of fire codes) just inside the existing outside wall. Use fiberglass insulation batts behind thick drywall and attach acoustical foam to the inside (band side). Be sure your new wall does not contact the existing wall.
Building codes and common sense mandate a window or door through which an adult could easily exit the room in the case of fire. If you must have a window in your second parallel wall, keep it at the minimum required size for fire egress and cover it with foam and heavy fabric in a manner that permits removal in an emergency.
To reduce transmission from the ceiling to the floor above, you could install a suspended ceiling with acoustic tile. You could also attach acoustic foam to the ceiling. If you are finishing an unfinished basement, first put insulation under the floor above the basement (ceiling of basement) and then put in a suspended ceiling.
If all of this sounds overwhelming and none of your bandmates are willing to buy a home out in the country with no close neighbors, you might want to look at other alternatives for silent band practice such as the ones covered in this question on Music Stack Exchange - Should I use JamHub or Mixer and Headphone Amp for silent band practice?