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A steep driveway like this home in Cobb County could
have been avoided by utilizing one of four options. |
Steep driveways leading up to a garage are like a bad gift given to the homeowner from their homebuilder.
The effects are irreversible and pose a constant problem for those that live with them. Children can’t play on them, yard sales are out of the question, and grandparents have a hard time getting out of their vehicles when they visit because their door keeps closing on them.
It doesn’t have to be this way! With a little foresight and planning by the homebuilder, the steepness of the driveway can be minimized.
Lowering the overall elevation of the lot is the best option. If that isn’t possible, here are four additional options that can prevent a steep driveway.
1. Lower the garage floor elevation
For houses with a basement foundation, instead of placing the garage floor near the top of the basement wall, lower the garage floor. This will reduce the slope of the driveway while keeping the First Floor elevation where it needs to be.
When you drop the garage slab you will have to add additional steps to get from the slab up to the First Floor. Many garages built in Atlanta aren’t big enough to accommodate the additional steps. So, the garage has to be made larger to allow room for the stairway and the cars.
For every 7” you drop the garage floor, you need to allow for 11” of stairway tread. To prevent a long stairway extending into the car area, you can create a 4’-0” x 4’-0” landing at the entry door, then have the stairs run parallel to the parked cars.
If you are going to choose this option, make sure you have enough room for the treads and risers in your garage.
2. Set the house farther back from the road
When you set the garage farther from the road, you decrease the angle of the driveway. This may not be possible if your lot is small or your house is already positioned close to the rear building line.
Production houses in metro subdivisions usually have enough room to move the house back, which reduces the angle. Some of the custom homes on infill lots inside the perimeter are very close to – if not touching – two or more of the building setbacks and this isn’t a viable option for you.
When the house is in a subdivision, then the other houses may have already created a typical setback distance from the road. However, if you can move the house just 5’-0” farther back, it will help minimize the slope of the driveway.
Another option similar to this is to keep the front of the house in the same place, but modify the house plans to slide the garage back farther from the road.
3. Lower the house and basement elevation
In most of the houses built in Atlanta with a basement foundation, the walkout level of the basement is what establishes the elevation of the entire house. Builders, land planners and surveyors start by locating where the walkout level will be, and then add to that the height of the basement walls, plus the height of the First Floor flooring system and arrive at the elevation of the house.
An often-overlooked option is to lower the basement floor elevation farther into the ground, which lowers the whole house. This means the basement level is set into the ground and it is no longer a walkout onto the grade.
The basement can be lowered as much as 3’-0” into the ground and still allow for legal egress windows to be used without window wells. In the Midwest this is called a “Daylight” basement. If the plans call for an exterior door in the basement, then a short area well can be added to the outside of the basement to allow the homeowners to walk up and onto their yard.
One thing to note with this option: If the lot topo doesn’t allow for positive drainage of the foundation drain tile to an open area, then a sump pump may be needed to pump any drain tile water up and away from the foundation.
4. Shorten the height of the basement walls
If the original house plans call for 9’-0” or taller basement walls, then those walls could be reduced to 8’-0” tall, which would lower the First Floor elevation.
Basement walls used to be 7’-4” tall (because that is the height of 11 8” cmu blocks). Then, as cast-in-place concrete walls became more popular, 8’-0” tall walls were common because wall form manufacturers made 8’-0” tall forms. Later, 9’-0” tall walls became the standard because they made the basement feel less like a root cellar and more like a comfortable living level.
Recently, we’ve been constructing more 10’-0” and 12’-0” tall basement walls for our luxury custom home builders. 8’-0” tall basement walls are still seen in some production homes across Atlanta.
Even though an 8’-0” tall basement is less desirable, it is an option that will allow you to lower the First Floor and garage elevations.
Planning is key
Before you start grading the lot, determine if the slope of the driveway will be an issue. If so, see if you can implement one of these ideas to minimize that slope and give your homeowners a driveway they can enjoy.