Step up from garage

Does anyone have a good graphic of the minimum step up from a garage into a house. Also would a 55 plus community necessarily be exempt from this requirement? I know the AHJ would have final say, but it seems to me that the step up requirement for safety would override.

Why do you think there is a minimum step up?

Somewhere in code it states a minimum step up of about 2 - 4 ". A safety issue, to keep spilled liquids from entering the house. I know I’ve seen that somewhere.

I know of no requirement.

Call you local AHJ to check for your area.

The garage floor is slanted. I’ll just advise that spilled liquids, water, could enter house.

Thanks Michael


I have run across that also in the past. Haven’t seen it in a while, so it may be an old requirement. I also remember it being about 4 inches. Sorry I can’t be more help right now.

I see steps going down to a basement from garages from time to time and in fact my son built his house with one.

No issues…


I understand Mike. I do also. I also see those same basement accesses on newer homes with “curbs” built around them. Perhaps it is a local town thing. Dunno.

R309.1 Opening Penetration
Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and the residence shall be equipped with solid wood doors not less than 1-3/8” (35 mm) in thickness, solid- or honeycomb-core steel doors not less than 1-3/8” (35 mm) thick, or 20-minute fire-rated doors.
In addition, InterNACHI inspectors can check for the following while inspecting doors that separate garages from living areas:

While not required by the IRC, it is helpful if there is at least one step leading up to the door from the garage. Gasoline fumes and other explosive gases are heavier than air, and they will accumulate at ground level. Their entry beneath a door will be slowed by an elevation increase.
Doors should have tight seals around their joints to prevent seepage of fumes into the living areas of the house. Carbon monoxide,with the same approximate density as air (and often warmer than surrounding air), will easily rise above the base of an elevated door and leak through unsealed joints.
Doors should be self-closing. Many homeowners find these doors inconvenient, but they are safer than doors that can be left ajar. While this requirement is no longer listed in the IRC, it is still a valuable recommendation.
If doors have windows, the glass should be fire-rated.
Pet doors should not be installed in fire-rated doors. Pet doors will violate the integrity of a fire barrier.

Requirement 1 – Accessible Entrance on an Accessible Route
Accessible Routes to Garages

  1. Q. Is it necessary to have an accessible path of travel from a subterranean garage to single-story covered multifamily dwellings built on top of the garage?
    A. Yes. The Fair Housing Act requires that there be an accessible building entrance on an accessible route. To satisfy Requirement 1 of the Guidelines, there would have to be an accessible route leading to grade level entrances serving the single-story dwelling units from a public street or sidewalk or other pedestrian arrival point. The below grade parking garage is a public and common use facility. Therefore, there must also be an accessible route from this parking area to the covered dwelling units. This may be provided either by a properly sloped ramp leading from the below grade parking to grade level, or by means of an elevator from the parking garage to the dwelling units.
Q. Does the route leading from inside a private attached garage to the dwelling unit have to be accessible?
A. No. Under Requirement 1 of the Guidelines, there must be an accessible entrance to the dwelling unit on an accessible route. However, this route and entrance need not originate inside the garage. Most units with attached garages have a separate main entry, and this would be the entrance required to be accessible. Thus, if there were one or two steps inside the garage leading into the unit, there would be no requirement to put a ramp in place of the steps. However, the door connecting the garage and dwelling unit would have to meet the requirements for usable doors.

Many of the retirement communities here do not have a variation in height from the garage slab to the interior. I have noticed that the garage floors in these homes often have a steeper pitch than normal.

Perhaps the steeper pitch is the loophole to avoid the step.

A common misconception. There is no requirement that the garage slab be on a different level from the house. I just gave a CO to a new home that was intentionally designed that way for wheelchair accessibility.

Ditto :slight_smile:

Charles -

IRC does not require a step-up, although the 10 years I lived in Texas with slabs many builders did it. They are required to slope away from the house door for obvious reasons.

Excellent comments everyone. 99.9 % of houses I have inspected have a step up into the house. I simply advised the new homeowner of the possibility of liquids getting into house. He really did not consider it a problem. I do know however that I have seen a “graphic” showing a necessary step up, but I can’t find it. (sr. moment). Thanks everyone for your comments.

The 1999 BOCA had the following-

407.5 Door sills- The sills of all door openings between private garages and adjacent interior spaces shall be raised not less than 4 inches above the garage floor.
Not mandated by the IRC.

There is no requirement today other than common sense to do so and some Jurisdictions in this area require it.

Check with your local jurisdiction to make sure. :slight_smile:

Dan, yeh that’s pretty much standard practice here, to drop the slab in the garage, even if not required and also slope it. And even though the slab in the garage is dropped the walls aren’t. Curbs are poured w/ slab at exterior walls, keeping wall heights the same.
Also 8x16" vents (for fumes) are installed here within 12" to the floor on bottom of exterior walls. 2 for a 2 car garage, 3 for 3 car garage.

No step or slope is required by the IRC.

Joe -

Look in IRC R309.1 and you’ll find the requirement to slope to floor drain or vehicle door (its under Non-Combustible floors - gets overlooked a lot).