Using existing attic space?

[Robert]

I'm adding an addition to a commercial property that has unused 6'-6" high attic space. Can I build a stair and use a portion of the existing attic as storage even though the finished attic ceiling (non-sloping) will only be 6'-6" +/-? I know the requirement of 7'-6" minimum height at egress conditions (CA) and am wondering if that is only for habitable spaces or corridors? It is also conceivable the owner will drag a desk up there and use the space as a workspace as he would also like a window, but not sure if that would change the ceiling height requirement. The stairs will be located in an existing equipment/storage room. Thanks.

 

[Francis Vineyard]

Don't know about CA but in the IEBC permits 7 ft. for corridors and where converting an unhabitable space.

 

[cda]

IFC


315.3.4 Attic, under-floor and concealed spaces.
Attic, under-floor and concealed spaces used for storage of combustible materials shall be protected on the storage side as required for 1-hour fire-resistance-rated construction. Openings shall be protected by assemblies that are self-closing and are of noncombustible construction or solid wood core not less than 13/4 inches (44.5 mm) in thickness. Storage shall not be placed on exposed joists.



Exceptions:

1. Areas protected by approved automatic sprinkler systems.

 

[Robert]

Thank you....so far so good. Anything about ceiling heights?

 

[SCBO1]

Not knowing the particulars, does the floor joist get checked for spans if applicable?
I know you said commercial property.

 

[cda]

Thank you....so far so good. Anything about ceiling heights?

Nothing in ifc but would say has to meet ibc

7 feet??

Since a door is required

 

[steveray]

i'd have to find a code path, but wouldn't get too crazy on headroom for "storage only" ....Like junk ending up in a crawlspace...Like PC said, if the structure was designed for it.

 

[north star]

@ ~ @

Robert,

So that we can attempt to assist you, what is the applicable
Code that is in place [ i.e. - the CA Bldg. Code, or the CA
Existing Bldg. Code, or other ? ].

Also, are you actually converting the attic space in to a
Habitable Space [ RE: Floor live loads, ...MOE, ...air
conditioning, other ? ].

Thanks !

@ ~ @

 

[Robert]

Thanks for the replies. The code I'm using is the 2016 CBC. I have not looked at the CA existing Bldg. Code but maybe that would be less restrictive. The CBC 1208.2 states 7'-6" min. for "occupiable or habitable space" and 7' min. for Storage. Yes, the floor structure will need strengthening, and the end result will be 6'-6" headroom...about 150 sq. ft. We would have to lift the roof to get any more height. I think the city will see this space as habitable/occupiable as the owner wants it conditioned, and a new window, light and outlets. It will be used as Storage but he will also be working up there at a desk from time to time. S occupancy or B? With the low headroom, will that define it as non-habitable Storage? And if so, can we still add the window, plugs, AC?

I worked in an architect's firm 7 years ago and they bought a commercial space to be used as their new office and added an upstairs interior "library" floor (employee use only)...open to the floor below (but not a mezzanine) that had a low headroom of just over 6'. I asked the principal about the height and he said there was no headroom requirement in commercial work. But everything I'm seeing states otherwise. Even if considered a soffit or furred ceiling, the code still states 7' min.

 

[north star]

& * & * &

Robert,

My take on your application is that because you
are changing the attic space in to a habitable "office
space", ...that the requirements for a B occ. would
apply, hence, the 7'-0" minimum, along with the
other requirements.

Hopefully, some other California people on here
will chime in.

& * & * &

 

[cda]

Thanks for the replies. The code I'm using is the 2016 CBC. I have not looked at the CA existing Bldg. Code but maybe that would be less restrictive. The CBC 1208.2 states 7'-6" min. for "occupiable or habitable space" and 7' min. for Storage. Yes, the floor structure will need strengthening, and the end result will be 6'-6" headroom...about 150 sq. ft. We would have to lift the roof to get any more height. I think the city will see this space as habitable/occupiable as the owner wants it conditioned, and a new window, light and outlets. It will be used as Storage but he will also be working up there at a desk from time to time. S occupancy or B? With the low headroom, will that define it as non-habitable Storage? And if so, can we still add the window, plugs, AC?

I worked in an architect's firm 7 years ago and they bought a commercial space to be used as their new office and added an upstairs interior "library" floor (employee use only)...open to the floor below (but not a mezzanine) that had a low headroom of just over 6'. I asked the principal about the height and he said there was no headroom requirement in commercial work. But everything I'm seeing states otherwise. Even if considered a soffit or furred ceiling, the code still states 7' min.

Check the calif section of the fire code I cited before