Why build downsloping driveways to below grade garages?

When not necessitated by topography.

Our neighborhood is all split-levels, ranches, and 2-stories built in the late 50s and early 60s. Ours is a split, with a level drive to a garage at grade level. (Actually, slightly above street level, so water drains away from the garage to the street.). The living room/kitchen are slightly above grade with a subbasement below.

Some split-level homes in the area have the driveway slanting down to a garage below grade level, such that the living area is at grade. Here is a realtor.com photo of one with a 1-car garage.. Living/dining rooms and kitchen are to the right with a subbasement below, and bedrooms above garage.

That creates issues WRT rainwater and snow/ice, and the retaining walls often need rebuilding. Is there any economic reason some homes would be built one way or the other? Is one mode of construction cheaper than the other? Was it just to add slight variety? Some below grade garages are 1- or 2-car. The topography is very flat. All homes were built by the same builder.

The reasons for below-grade garages may vary, but typically when I see them around here, the purpose is to maximize usable floor space. This is especially important when building a large house (in terms of square footage) on a relatively narrow lot, something frequently seen in “infill” projects, where small old houses are demolished in an area of high land value, and replaced by large houses that in many cases have to be shoe-horned into a disproportionately narrow lot.

There may well be other reasons for below-grade garages, but this is what I typically see.

I agree it makes snow removal a pain. One possible solution that could work particularly well on a sloped driveway is a driveway heating system.

I’m looking out my front window at 2 side-by-side split levels. They are essentially mirror images of each other, but one has a downward sloping drive, and the other is level.

My understanding is that the same builder built all of these houses at the same time on previously undeveloped land. My wife and I have tried to figure out what was involved in moving fill. The homes are generally just a couple of feet above the street - which allows for ready drainage to front and back. The downscoping garages just seem a weird, unnecessary, and potentially problematic design choice.

I note that homes by our builder have a cell deserved reputation for being very solidly constructed. But they are not without design oddities.

The obvious advantage I can see from the photo in the OP is that you get the part of the house (bedrooms?) above the garage at almost the same level as the rest of the house, so you are only going up/down a few steps to get around inside. It’s almost all on the same level, rather than having to go all the way up a full set of stairs to a second story.

The city of Toronto zoning bylaws prohibit reverse slope driveways (I guess they want to discourage custom connections to the storm sewer). You can get an exemption, though.

I don’t think you understand what I am describing. All of the split-levels are constructed the same way, such that there are short 1/2-flights of 6-8 steps between each living area. The ONLY difference is that some have a “reverse slope” driveway (to use hogarth’s term.) Here is one with a level drive. As you can see - same steps required inside both.

FTR, here’s an example of a typical configuration showing what I was talking about. You can see that the elevation of the first floor, with the two-car garage tucked completely underneath it, allows for a level first floor across the whole length and width of the house, and thus ditto for the second floor, too. The first-floor elevation also allows for a big-window, high-ceiling basement.

ETA: Looking at the gradual slope of that particular driveway, it doesn’t look like snow removal would be an issue at all. I’ve seen others that were much steeper.

ETA2: The close proximity of this big house with the one immediately to the right of it, plus the fact that one can see on the house on the right that it has above-ground electrical service, suggests that this is all infill in an older neighbourhood that previously had smaller houses, likely single-story.

IANA expert …

Back in those days “split level” was the new fashionable hotness as ranch houses became passe. Internally, the various short staircases inside added visual interest, reduced (or at least broke up) the hassle of lugging stuff up and down. And had the really neat advantage of fitting more usable floorspace into a given lot size as suburbia was really getting going, the economy was booming, and folks wanted more square feet for the buck.

Sticking the garage a half-story below grade made all that easer for the builder. Who did not give a crap about how that impacted snow removal, basement wall longevity, etc.


Garages and their blank doors have always been a bit of an aesthetic negative. Of late, many HOAs in wealthier areas require that garage doors not face directly to the street; too ugly for the comfy class’s delicate sensibilities. That’s also why the garage door in @wolfpup’s pic just above is decorative with arches, windows, board and batten facing, not just a plain plane; they’re prettier that way.

Back in the day one way to semi-hide a garage inexpensively was simply to put it half-buried. Exactly as @wolfpup’s pic demonstrates.


Last of all, one of the complaints about suburbia as it first got going was the unending sameness. The original Levittown was literally all the same house, one after the other after the other.

So pretty quickly builders came up with cheap ways to improve the apparent variety. Same houses built in mirror images. Two types of e.g. 2BRs that differ only a bit in layout. 2 or 3 different facing and roof treatments for the same underlying box. And 2 or 3 different colors of original paint. Suddenly they have 20 kinds of houses in their inventory at negligible incremental cost.

And last of all, adding fake hilliness to the area buy grading some lots down a bit and using that dirt to grade some lots a bit higher. It’s all about visual variety. At as close to zero incremental cost as possible.

Is it possible that not all of the houses were originally built with a garage? In my immediate neighborhood, the houses that were built with a garage have an alley between adjacent houses that runs from the front sidewalk to the backyard garage. The sloped driveway happens when a basement garage is added to a house that did not originally have one - you have to slope the driveway down because more than half the basement is underground. Without the slope, you could have a driveway, but not a garage.

That cannot be true unless the builder is using TARDIS technology. With the garage floor at ground level, either the garage must have a much lower ceiling, or the bedrooms above the garage must be higher.

More acurately, that cannot be true unless for the non-sunken garage there are front steps to get up from grade to the lowest level of the living area. Conversely, with the sunken garage the front door can be at grade.

Yes, fair point. But either way, I’m pretty sure the reason behind it is to have the bedroom floor level (above the garage) closer to the living room floor level.

Agreed. Which is exactly the point of the split-level design. No full staircases, just a couple more half-staircases.

As I understand it, ALL split-level homes have some part of the building partly below grade. What possible difference to the drainage can it possibly make whether it’s the garage or some other part of the house that’s below grade?

I’m curious - have all of you looked at the photos I linked? The first shows a split level with a reverse-slope driveway to a below grade garage. The second as a level (actually slightly upsloping) drive to an at (slightly above grade) garage. My house is like the second.

The second one actually has an unusual variation where the front door is at grade - same as the garage, but then you need to step up a couple of steps inside to the living room. With my house - and most with grade-level garages, the exterior landscaping has approximately 5 steps up to the front entry door.

Both level and reverse driveway homes have the exact same relative internal floor plan. The lowest level is a subbasement, 1/2 floor BELOW the garage. Generally with small windows high on the walls, just at ground level. Or window wells. Up 7 or so steps from the subbasement is a family room and 1/2 bath on the same level as the garage. Up 1/2 flight are the living/dining rooms and kitchen. Up 7 more steps is the bedroom/bathroom level - with one or 2 bedrooms directly above the garage.

If the homes with level drives did not have a subbasement, NO PART WOULD BE BELOW GRADE. I walk directly out of my lower level family room onto our ground-level back yard.

I wonder at the reason for the confusion - or if there really is confusion, as I am sitting in the living room of just such a house as I type this. The interior photos on the links I attached should show the interior configuration.

The driveway provides a completely non-absorbent path for rain & snowmelt to flow into the garage, attacking the house structure from the interior.

The OP lives in greater Chicago, where substantially all houses have basements and hence have walls that begin below grade at least a couple feet, and maybe 10 feet. Having the grade, be it concrete, or dirt, or grass slope towards the house greatly increases the likelihood of water intrusion problems. Having a paved driveway slope towards the house is building a freeway to problems, not just a cowpath to problems.

That’s the difference.

I’m in that area (Chicago’s western suburbs), and there are a handful of such houses in my neighborhood. All of them are probably 1950s or 1960s vintage. Property lots, in general, are pretty narrow in my neighborhood, and I imagine that, as others have suggested, it’s a way to include a garage in a house design while maximizing available square footage in the house (by having a living space above the garage).

(For what it’s worth, this neighborhood also has alleys behind all the houses, and 90+% of the houses have freestanding garages in their back yards, opening into the alleys.)

But, this area is also flat as a pancake, and has a long reputation for having basements flood during periods of heavy rain. I have to believe that, as @LSLGuy says, having a paved driveway which directs water towards your house would just add to the flooding issues, as well as being annoying-to-problematic for driving into and out of your garage in snowy or icy conditions.

2 reasons come to mind: one is to diminish the look of the garage doors and try to improve the curb appeal, the second is to minimize the steps up to the main level(s) of the house.

Overall it is generally a manageable negative though one thing I would be concerned about is slipping on ice into the garage and perhaps into the sides, not just the door/ open door area. All my houses have had the opposite slant, and there are times I (quite purposely) slid onto the street, or took a run at it to get up. With an inverted ramp I would tend not to use it unless I knew it was OK, though that is a rare happening.

I’m not sure what you are saying. I can’t believe that you’re disputing that what I said must be true?

Yes - you and I are obviously misunderstanding each other - and each of us apparently does not understand the basis for the other’s misunderstanding.

In both homes, the bedroom floor level is exactly the same distance from the living room level.