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Detached garage/Upstairs apartment egress

4

4thorns

Bronze Member
Joined
Jul 7, 2011
Messages
65
I think I'm in the right place for this. I'm designing a detached garage that has an apartment upstairs. My first concern was egress from the apartment. I know that egress can not be obtained through the garage itself. What I would like to do is exit the apartment, down a set of stairs that is within the building but has a fire resistant wall and door between the stairwell and the garage. Obviously the rest of the garage would be sealed as well. Again, both garage and stairwell are within the same four walls and roof. I've done some research but am unable to find clarification as to whether or not this is acceptable. I'm trying to avoid an exterior set of stairs from the apartment, though it might not be a bad idea any way. This apartment would include kitchen, bedroom with egress window, bath etc. All the comforts of home. From what I've found on the web it seems to be more of a local deal, zoning being the controlling factor in most cases. This isn't a one off deal that I can just contact some one and make sure it's ok. It could wind up anywhere in the states.

Could someone chime in with an opinion and maybe some code reference (IRC-IBC) pertaining to this situation?

Thanks,

Doug
 
So is the question

Can you build the garage apt setup?

Can you build it in any city?

I understand you have an exiting question also
 
It's no different than any other house with an attached garage, the protected stairs dump you outside or into an alcove that has a rated door into the garage and one to outside. A deck at one gable end provides another door out...

Cantilevered attic trusses that rise from the fascia rather than the wall plates buys you room upstairs.
 
DRP said:
It's no different than any other house with an attached garage, the protected stairs dump you outside or into an alcove that has a rated door into the garage and one to outside. A deck at one gable end provides another door out...Cantilevered attic trusses that rise from the fascia rather than the wall plates buys you room upstairs.
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Are you saying there needs to be 2 egress means from the second floor. We are doing one where the only access to the apt is thru the deck not the garage.
 
This is the right place.

As DRP suggested if you install another entrance from the garage then the sleeping area or bedroom cannot be at the stair entrance.

Should you have an efficiency apartment layout may need to separate the bedroom otherwise it may be the BO interpretation as having an opening directly into the sleeping area which is prohibited.

R302.5.1 Opening protection. Openings from a private garage directly into a room used for sleeping purposes shall not be permitted.

Francis
 
IBC or IRC......

R311.4.1 Exit door required.

Not less than one exit door conforming to this section shall be provided for each dwelling unit. The required exit door shall provide for direct access from the habitable portions of the dwelling............ "to the exterior without requiring travel through a garage"......... Access to habitable levels not having an exit in accordance with this section shall be by a ramp in accordance with Section R311.6 or a stairway in accordance with Section R311.5.
 
Thanks for the replies everyone. I've had a chance this morning to study chapter 3 of the 2009 IRC. It looks like I should be good with my original design.
 
If the stairway is separated from the garage by 1/2" gypsum, and no prtion goes through the garage area to get to the exterior, there would be no issues with an interior stairway. The ceiling would have to be protected with 5/8" gypsum based on 309.2 of 2003 IRC (we are way behind on adoptionof current codes). I would also asked the question if the walls supporting the dwelling unit require additional protection? Should be minimum 1/2" gypsum for all walls per same section. How would SIP walls be addressed under this situation. Does the OSB sheathing meet the "or equivalent" portion of this requirement?
 
Inspector 102 said:
If the stairway is separated from the garage by 1/2" gypsum, and no prtion goes through the garage area to get to the exterior, there would be no issues with an interior stairway. The ceiling would have to be protected with 5/8" gypsum based on 309.2 of 2003 IRC (we are way behind on adoptionof current codes). I would also asked the question if the walls supporting the dwelling unit require additional protection? Should be minimum 1/2" gypsum for all walls per same section. How would SIP walls be addressed under this situation. Does the OSB sheathing meet the "or equivalent" portion of this requirement?
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I do not believe OSB meets the 1/2"equivilant, but you also need to consider the thermal barrier required over the foam, and I don't believe that OSB qualifies.
 
You probably need to drywall the under side of the stairs also.....

R311.2.2 Under stair protection.

Enclosed accessible space under stairs shall have walls, under stair surface and any soffits protected on the enclosed side with ½-inch (12.7 mm) gypsum board.
 
Is the utility room part of the residence as a basement be an unfinished portion without gypsum on the ceiling and exterior walls? If not then a 20 min. door is not required.

Would the same apply to the entry?

Francis
 
steveray said:
You probably need to drywall the under side of the stairs also.....R311.2.2 Under stair protection.

Enclosed accessible space under stairs shall have walls, under stair surface and any soffits protected on the enclosed side with ½-inch (12.7 mm) gypsum board.
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It appear to be enclosed with 2x6 walls shown on the 1st floor plan.
 
The utility room will probably be treated as part of the basement since it most likely won't have a fire rated door. I think the short section of wall that has the door in it will have to go in after the rest of

the walls and ceiling have been dry walled.

If someone decides that they want to utilize the space under the stairs then I agree that it falls under R311.2.2.
 
4thorns, after looking over your two designs, I have these comments. It appears to me that the design is possibly.

Be aware of min. sf of rooms and ceiling height requirements in your design.

Window egress from the bedrooms 5.7sf.

Garage post protection and beam protection.

Door closer on stairway door and a closer on the door of the utility room if thtas the location of the heating with room air from outside?

pc1
 
pc1.

I just went thru the minimum requirements again to be safe. Seems to make it OK. It's a little tight but it's not a mansion. Just some extra space for friends or family to crash in for the weekend. Actually if it were my choice it would only have 1 bedroom and the extra space would be distributed between the living area and kitchen. Nice little bachelor pad!

The windows in the bedrooms meet egress.

I hate to say it but post protection never entered my mind. Take it out with the car and the whole place comes down. Definitely something I will keep in mind for this project and in the future as well. If anyone has or knows of some details for this I'd appreciate a push in the right direction. My first thought would be a steel column embedded in the concrete floor. The top of the column would be attached to a built up LVL beam and will be a little harder to restrain. Joists will attach to the sides of the beam so if the post gets hit the load should be resisted by the 2nd floor system and the outside walls. Again, any help on this one would be appreciated.

Heating source and location, electrical, water etc. would be up to the buyer and local codes. Door closers would be as well but probably worth a mention on the plans.

Thanks again for the replies,

Doug
 
Protection as in from fire, you're allowed to run into it you just can't burn it.

Full log below, watch your penetrations, you'll need to get the drains down in a drywall chase or something.

Wall stiffeners on all but the stairwall, is it ok?
 
Thanks for the observations DRP

Protection as in from fire, you're allowed to run into it you just can't burn it.
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So....I can drop the place on top of me if I hit the post with my truck but I can't fall into the garage from upstairs (with the place on top of me) because my post burned.....Interesting.

Full log below, watch your penetrations, you'll need to get the drains down in a drywall chase or something.
Click to expand...
I will definitely note the plans to require a properly fire resistant chase for plumbing etc. Bear in mind that this is a very basic drawing and is by no means complete.

Wall stiffeners on all but the stairwall, is it ok?
Click to expand...
The "10" located between the stairs and the utility room is also a wall stiffener within the wall. Just a couple of 2x's turned perpendicular to the log wall with another laid against them and lagged to the logs. The worst of the roof load is at the other side of the stairs and has adequate support. I might require a closer log fastener spacing in this area in a high wind zone but for the most part our standard should suffice.
 
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