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Habitable basement ceiling height.

Mr Softy

Mr Softy

Silver Member
Joined
Jul 7, 2011
Messages
162
Location
Our Fair City
House in question -

single family built under MA 7th Edition (based on 2003 IRC). basement ceiling height amended to allow 6-8 for habitable basements.

basement built is one large room with a ceiling height of 6-10 finish floor to finish ceiling. but.

there's a duct trunk line running down the center of the room which reduces the ceiling height to 6-0 under the soffitted duct (soffit is approximately 4' wide).

it has always been our interpretation that this disqualifies the entire basement space as habitable, as the projection is larger than that allowed by the exception (4").

it is the builders interpretation that the basement is still habitable, but that one does not include the space under the duct in the sq footage calculation for finshed space.

IRC commentary grants this measurement in the room dimension section, but then seems to disallow it in the ceiling height section.

anyone else come across this?
 
two habitable spaces in the basement separated by one non-habitable one.

The theory that a duct renders the entire space uninhabitable is as absurd in a basement as declaring an entire floor to be uninhabitable because it contains a garage.
 
That is a gray section and kinda confusing.....I think you can look at furred ceilings provisions and things like that...if that really were the intent, we could never finish the second floor of a cape....I think it is a case by case basis if it seems reasonable....I would not have too much heartburn about it...
 
Yes, I think we can use 'Height Effect on Room Area' section which states that the area under a furred ceiling less than the required height shall not be calculated as floor area. It says nothing about that space possibly running down the middle of the room.

So the further issue is - can one go from one habitable side to the other by passing under a non-complinat low bridge (the 6-0 height duct). this is well below the minimum required 6-6 door height. should the space have compliant access from one side to the other?
 
"can one go from one habitable side to the other by passing under a non-complinatlow bridge (the 6-0 height duct). this is well below the minimum required 6-6 door height.

should the space have compliant access from one side to the other?"
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IMO, the minimum ceiling height of this proposed "habitable space" ( from Section R305.1, 2003& 2006 IRC ) should be consistent throughout the entire space. It will be marketed as a

habitable space. Why not have it actually constructed that way?

FWIW, the builders interpretation does not count. Also, while the Commentary may

be beneficial in providing background on this topic, it is not a legal document,

therefore not enforceable.

Also, if this is a gray area, then aren't you / we required to use Section R102.1 -

APPLICABILITY

R102.1 General.

Where, in any specific case, different sections of this code specify different

materials, methods of construction or other requirements, the most restrictive

shall govern. Where there is a conflict between a general requirement and a

specific requirement, the specific requirement shall be applicable.



.
 
the builder's interp does count. just not as much as mine. :)

and, of course, it has been marketed as habitable space.

my interp would be that if i can't get to the isolated habitable space through a compliant area (or opening) it isn't habitable. the only habitable space in the basement is on the stair side of the low hanging duct.
 
Mr Softy said:
the builder's interp does count. just not as much as mine. :) and, of course, it has been marketed as habitable space. my interp would be that if i can't get to the isolated habitable space through a compliant area (or opening) it isn't habitable. the only habitable space in the basement is on the stair side of the low hanging duct.
Click to expand...
What does 'marketed' have to do with the price of tea in China? Or the building code?
 
R305.1.1 Basements.

Portions of basements that do not contain habitable space , hallways, bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).

Exception: Beams, girders, ducts or other obstructions may project to within 6 feet 4 inches (1931 mm) of the finished floor.

Resize the entire duct length or where you would cross under it to get to the other side.
 
to further muddy the waters...

the original submitted plans showed nothing in the basement. labelled as 'Future Laundry, Bath, Rec-room'.

inspection has the space finished with wall-to-wall rugs, ceiling cans, cable hookup - the works for a real nice man-cave or something similar.

but there's no required egress. to supply either a window, or a bulkhead, would require a return trip to the Zoning Board. something that would probably not work out well.

the builders proposal is to call the basement non-habitable and be done with it.
 
Mr Softy said:
to further muddy the waters... the original submitted plans showed nothing in the basement. labelled as 'Future Laundry, Bath, Rec-room'. inspection has the space finished with wall-to-wall rugs, ceiling cans, cable hookup - the works for a real nice man-cave or something similar. but there's no required egress. to supply either a window, or a bulkhead, would require a return trip to the Zoning Board. something that would probably not work out well. the builders proposal is to call the basement non-habitable and be done with it.
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None of this supports your policy of, one low duct = entire basement uninhabitable. Including what the contractor wants.
 
Mr Softy said:
Yes, I think we can use 'Height Effect on Room Area' section which states that the area under a furred ceiling less than the required height shall not be calculated as floor area. It says nothing about that space possibly running down the middle of the room. So the further issue is - can one go from one habitable side to the other by passing under a non-complinat low bridge (the 6-0 height duct). this is well below the minimum required 6-6 door height. should the space have compliant access from one side to the other?
Click to expand...
Underline emphasis added; R311.4.2 The required exit door shall be a side-hinged door not less than 3 feet in width and 6 feet 8 inches in height. Other doors shall not be required to comply with these minimum dimensions.
Did MA amend that too?

Would it satisfy if a free-standing partition or fixed furniture with a doorway was under the soffit or duct? Could have a wall of doors or call it one big door; fix it or just move on.
 
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Francis Vineyard said:
Underline emphasis added; R311.4.2 The required exit door shall be a side-hinged door not less than 3 feet in width and 6 feet 8 inches in height. Other doors shall not be required to comply with these minimum dimensions.
Did MA amend that too?

Would it satisfy if a free-standing partition or fixed furniture with a doorway was under the soffit or duct? Could have a wall of doors or call it one big door; fix it or just move on.
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I'd be OK with a passageway of 6-6 under the duct to make the entire (both sides of the) basement habitable -

"5311.4.2.1 Interior Doors. All doors providing access to habitable rooms shall have a minimum nominal width of 30 inches (762 mm) and a minimum nominal height of six feet, six inches "

or even 6-4

"5305.1 Minimum Height. Exceptions: 2...and beams, girders, ducts or other obstructions may project to within six feet, four inches (1931 mm) of the finished floor."

but there's still the problem with this -

"5310.1 Emergency Escape and Rescue Required. Basements with habitable space ...shall have at least one openable emergency escape and rescue opening."
 
Mr Softy said:
I'd be OK with a passageway of 6-6 under the duct to make the entire (both sides of the) basement habitable - "5311.4.2.1 Interior Doors. All doors providing access to habitable rooms shall have a minimum nominal width of 30 inches (762 mm) and a minimum nominal height of six feet, six inches " or even 6-4 "5305.1 Minimum Height. Exceptions: 2...and beams, girders, ducts or other obstructions may project to within six feet, four inches (1931 mm) of the finished floor." but there's still the problem with this - "5310.1 Emergency Escape and Rescue Required. Basements with habitable space ...shall have at least one openable emergency escape and rescue opening."
Click to expand...
You are shifting the target, again. The lack of EERO is another matter that should have been caught at review.
 
"What does 'marketed' have to do with the price of tea in China? Or the building code?"
Click to expand...
It has to do with keeping the contractor community happy and their willingness to come in toyour AHJ and build. If Mr. Softy' AHJ is like mine, it is not about the codes or being compliant,

it is more about keeping the contractors happy ( i.e. - trade offs ). If the AHJ "powers that be"

want to keep contractors coming in to their community, they have to be very aware of creating

& keeping a business friendly environment, which, ...here, means being lax on enforcement of

the codes. It is what it is!

In Mr. Softy' application, the "reworking" of the duct work may be the best option to

compliance of the "habitable" space.

.
 
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it has nothing to do with being 'lax on enforcement'

more coming to an acceptable interpretation, and solution, to all parties. sometimes it can be achieved. sometimes, like when the code is dimensionally specific, it can't

btw, Mr Softy is the AHJ. but at one time was the guy on the other side of the counter.
 
I DID state " here " Mr. Softy, meaning in my AHJ. Not necessarily in yours!

No disrespect intended! Here the contractors can & do overrule the codes,

...on occasion. :(

FWIW, would you please post a reply on here as to how your particular application

works out. Inquiring minds wanna know!

.
 
globe trekker said:
FWIW, would you please post a reply on here as to how your particular applicationworks out. Inquiring minds wanna know!

.
Click to expand...
the CO will say specifically 'non-habitable storage only' for the basement.

and no worries globetrekker, a bit of a misunderstanding on my part.
 
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