What is the standard size of a 1 car garage?

Answer 1

As is the case with many common things, there appear to be neither any official nor any de facto standard dimensions for garages. For a one-car garage, 12 feet by 22 feet (12' x 22') seems to be as close to "standard" as anything else.

Generally, consider 10' x 20' to be absolute minimum. Bigger, when possible, is almost certainly better. (Garage space is like closet space: it's hard to have too much.) A 12' width can help avoid the problems of narrower garages, such as not being able to fully open the car's doors when it's in the garage, as well as possibly provide some auxiliary storage space (for things other than a car, for example, tools or bicycles), or at least allow room to walk past the sides of the car while it's in the garage. Similarly, a 22' depth can allow room to walk past the ends of the car while it's in the garage and also possibly provide some auxiliary storage space.

If the garage needs to accommodate an over-size vehicle, it's important to consider not just the garage's width and depth but also its ceiling height and the width and height of its garage door opening, and to think in terms of minimum horizontal and vertical clearances, rather than merely in terms of interior dimensions.

Note that dimensions may be overall (the garage's outside dimensions) or interior(the garage's inside dimensions). Typically, dimensions are given without explicitly specifying which they are! Floor plans usually show interior dimensions inside the drawing of each room or area and may also show overall dimensions in the areas of the drawing that represent space outside of the building, so, if a floor plan has the dimensions 12' x 22' inside the drawing of the garage, those are likely to be the garage's interior dimensions. On the other hand, if a build-it-yourself garage kit is advertised as being for a 12' x 24' garage, it's likely that those are the garage's overall dimensions. The difference between overall and interior dimensions is, of course, taken up by the thickness of the walls, so overall dimensions are always greater than interior dimensions.

While it's possible to build walls of nearly any thickness, it's generally true that a wall's sturdiness is at least roughly proportional to its thickness. This is particularly true when the same construction method and materials are used to build walls of differing thicknesses. Sufficiently sturdy wood frame walls are likely to be at least approximately three and one-half inches (3 1/2") thick, but this varies with the exact construction method and materials used, how much weight (including their own) the walls have to support, and what other stresses (for example, from wind or from earthquakes) they must resist. Typical plain concrete block walls are about 8" thick, while stone-faced concrete block walls may be 12" or more thick.

In addition to providing walking space and auxiliary storage space, extra width and depth can help reduce the likelihood vehicles will collide with the garage's walls (from the inside of the garage, at least). Further, raising at least 2' to 3' of the floor by perhaps 2" to 3" along the rear wall of the garage (opposite the garage door) can provide drivers with tactile warning that the front of the vehicle is close to the wall. How wide the raised portion must be to be effective depends on how far the vehicle protrudes past where its tires contact the pavement. And, of course, a sufficiently wide part of the raised area closest to where the vehicle is parked must be kept clear, or the vehicle may simply push (say) the lawn mower into the wall, damaging not just the vehicle and the wall but also the lawn mower. Adding a raised floor section to a garage will increase the garage's cost, not least because the overall size of the garage will need to be increased, at least past the relatively minimal 12' x 22' in order to provide an adequately large parking area on the unraised portion of the floor. There are other advantages and disadvantages to raised floor sections, such as increasing the likelihood the auxiliary storage area's floor will remain dry (assuming that area is on the raised portion of the floor) and increasing the likelihood that someone will trip (on the edge of the raised section). Ideally, the raised floor should extend along the garage's side walls and through the garage door opening. This last would, however, not only additionally increase the garage's overall size but also require a (costly) custom made garage door.