Garages are very personal buildings. In the nine years I have been designing I do not believe that I have created the same Garage twice. Some want access to a second floor for storage or an apartment. Some need to stack cars on lifts to feed their auto Jones and others just need a place to park all the toys. Thinking about what you are hoping to achieve from your Garage may not be as simple as just saying “Honey, we need a garage”.
What is the main purpose of the Garage?
Most are looking to park a car for dry and warm access in times of inclement weather. For this you need to ask if you want to attach to the home or have a covered breezeway. Local jurisdictions will have say over how this breezeway can be attached and limitations to its size for the zoning in your area so having a knowledgeable designer and builder is helpful at the beginning. How many cars, what type of car, what type of toys, and how much storage are questions that need to be asked before and during the design process. The size of the garage may most depend on the potential vehicles that it will house. Think about the parking lot at the local grocery store. Are you comfortable getting in and out of your car? An average parking space is eight feet wide. Would you like more room in your Garage to get out with the groceries and the baby seat?
A quick calculation would look to have six feet +/- for the car and three feet (think of your homes front door) to either side for door swing. This would be a space of 12 feet per car. Making a two car garage at least 24’ wide to the interior! Add a typical foundation wythes to this mix and the Garage should be 25’-4” to the exterior. This exterior dimension also plays well with the current Residential Building Code when using a 16’ or 18’ overhead door. The doors themselves could add to this dimension and we will talk about that in another post.
Keep in mind that this has left no real room for storage to the sides if you want complete access although this is rarely addressed as part of the design despite what you may be told. The depth is usually pretty good at 24’ although as little as 22’ can be done. Keep in mind your vehicle when thinking about depth. You may be driving a midsize car now but the family van or SUV could be in the future. 22’ can get a little thin for that type of vehicle.
Interior stairs to a second floor will usually take up a side wall and generally rise to the center of the upper floor perpendicular to the ridge so that there will be sufficient headroom at the top of the stairs. This stairwell will eat into a bay of the garage fairly well and needs to be considered during the design process.
When designing a garage, there are certain building codes that can affect the design. For example, the overhead door sizes and the building code drive the width of your garage. The space required on either side of the door to meet the braced wall panel requirements of the Residential Building Code can drive the overall width of the Garage. It may not be as easy as having a 24’ square garage with two nine foot wide doors; it may need to be wider to accommodate the intent of the code.
There are several ways to meet the intent of the building code and each has their advantages and disadvantages. A particularly tall garage may have to have an engineer provide for the wall bracing. A tall foundation may need to be shortened to make the proscriptive method work thus resulting in a frame wall that is too tall and needs to be reviewed by an engineer. On the other end of this there are ways to work within the building code that can be implemented easily in the field and these are spelled out ad infinitum in the building code but these methods may limit how the Garage can be built. The builder and framing contractor should be aware and follow these methods but if more information or knowledge is needed then the designer should be able to answer the questions or these choices should already have been made during design.