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3rd Floor, Attic, Habitable Attic, Etc

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larryjones2078

Registered User
Joined
Mar 9, 2017
Messages
8
Location
New Jersey
I would appreciate some expert guidance with respect to a property I am under contract to purchase.

The property is zoned R1 and class 4A. It was built in 1888 and has spent the past 30 years as a professional office. I intend to convert it back to residential one family use. The building has a below grade basement, first and second floors and then a "3rd" floor which has been utilized and occupied for office space in its current configuration. The "3rd floor" has a fire escape. There is unfinished space above the "3rd floor" of about 5 feet in height and almost the full length and width of the house that I would refer to as the attic.

My architect has spoken to the code official who indicated that the "3rd floor" would be "habitable attic" space and subject to a limitation of not being more than 1/3 of the square footage of the two main floors (It is more like 70%). I don't think that is correct and don't believe that the 1/3 rule should apply in this instance. From IRC "ATTIC. The unfinished space between the ceiling joists of the top story and the roof rafters."

I believe that the 3rd floor is in fact a third floor. If I make this argument and the code official is forced to agree will I then run into issues with my 3rd floor being subject to fire sprinkler systems, onerous egress requirements, etc etc. In other words, should I not rattle the cage?

Thanks in advance, Larry
 
Sounds like you are lacking required height to make the attic usable.
 
@ ~ @ ~ @

larryjones2078,

1st, ...Welcome to the Building Codes Forum !

2nd, ...I do not believe that anyone can give
you an accurate answer on here; or any other
Forum, as to what the Code Official will do.

3rd, ...IMO, you should discuss this matter
thoroughly with your architect, and ask \
require them to explain to you clearly what
code sections are being referenced, and why
the Code Official has the view point that he \
she does.......If you are paying for services
from a registered, licensed and fully experienced
architect, IMO they owe you explanations,
...clarity of the application, and to be able to cite
chapter & verse from the applicable codes,
IN WRITING !

4th, ...it has been my experience to try and not
make any authorities mad or irritated when discussing
various applications.......They "should be" trying to
assist you, while protecting the interests of their
jurisdiction........That is not always the case though !
Tread lightly, courteously & respectfully !.....You
do not want to make any enemies from "The Get Go",
especially if you are planning to live there.

5th, ...again, thoroughly discuss this with your
architect........If they cannot or will not provide you
with the correct answers that you are seeking, you
may have to shop around for another architect.
Registered Design Professionals ( RDP's - i.e. -
architects ) are like every other profession, there
are some very good ones out there, and there
are other types a well !

6th, ...it is your money.......Get some clear under-
standing of everything involved in your case.


...I am going back down in to my bunker now ! :D


# : # : #
 
Thanks, North star. All good advice. The purpose of my post was to get a clear understanding of what the IRC dictates so that I could proceed with the basics necessary to deal with the architect and the code official.
 
cda said:
Sounds like you are lacking required height to make the attic usable.
Click to expand...
It doesn't sound like required height is an issue. He said there is a 5 foot space above the ceiling of the 3rd floor, not for the 3rd floor. From his description it sounds like the 3rd floor is normal height for rooms. Based on that height doesn't appear to be an issue.
 
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Right the building has three floors plus an attic which has a 5' ceiling height. Question is, would the 3rd floor be subject to the 1/3 square footage habitable attic rule in a single family residential application?
 
The habitable attic provisions are intended to permit an additional level above the 3rd story (above the basement).
Aside from the zoning restrictions on heights, the IRC prescribes construction of a basement plus 3 stories and a habitable attic.
With all due respect of other provisions, a 2 story over a basement the attic space could be enlarge into another story with a habitable attic above (finished or unfinished).
 
[RB] ATTIC, HABITABLE. A finished or unfinished area, not considered a story, complying with all of the following requirement:

1. The occupiable floor area is not less than 70 sf., in accordance with Section R304.

2. The occupiable floor area has a ceiling height in accordance with Section R305.

3. The occupiable space is enclosed by the roof assembly above, knee walls (if applicable) on the sides and the floor-ceiling assembly below.

The below illustration has the Virginia amended definition.
Definition.JPG
 
Thanks, FV. With the information you provided considered, would there be any specific requirements for the 3rd floor living space that the 2nd floor would not be subject to (i.e. sprinklers, multiple stair egress, etc)? I'm talking about the IRC, I know that local code could potentially call for something over and above.
 
In a "Change of Use", you may have to sprinkler based on the new use....Not sure what the rules are in Jersey....Here you would be fine as long as it met the requirements for habitable attic...
 
larryjones2078 said:
My architect has spoken to the code official who indicated that the "3rd floor" would be "habitable attic" space and subject to a limitation of not being more than 1/3 of the square footage of the two main floors (It is more like 70%).
Click to expand...
The "habitable attic" was added in the 2009 addition in an attempt to gain bonus space above the 3d floor while remaining in the IRC.
The code official is wrong IMO. The Residential Code applies to dwellings not more than three stories above grade plane which is what you have (plus what appears to be a habitable attic if you chose to use the space as such).
Do you have an interior stairway for access between the 2nd and 3d floor?
Since you are changing the occupancy from B to R, I don't see how avoid sprinklers (unless you move to the building to Michigan :) )
 
Hey Roger, The 3rd floor, which is about 70% of the overall building footprint, is the space in question here. There is actually a 5' high area above the 3rd floor which is the attic in this building. I don't intend to do anything with the attic other than insulate properly.

The official seems to be saying that #1- the 3rd floor is under consideration strictly as a "habitable attic" and must not be more than 1/3 of the main building footprint. #2 - IF I have more than the 1/3 rule then I would have to install a sprinkler system throughout the whole building ($20,000 ++ ??).

At the end of the day I'm forced to throw away perfectly good space on the 3rd floor (it is already finished and was in use for the professional offices) and whittle it down to be in compliance with the 1/3 rule.

The building is zoned R1 with a 4A classification (commercial - income producing).
 
larryjones2078,

I agree with Northstar above and think you should get some more specific written analysis from your architect citing specific code language and paragraph numbers. One trouble with code analysis is that the IRC is amended by each state and municipality differently, so any insight from a forum like this would not necessarily be correct for your particular location.

It could be there is a zoning regulation unrelated to the residential building code that is driving the requirements. Otherwise, I don't understand the 1/3 area limitation. I don't see that appearing in the IRC (un-amended) except in the context of a mezzanine (IRC R325); there may be some confusion if your "third floor" is a mezzanine or an actual third floor. I don't see why it couldn't be an actual 3rd floor provided it has proper structure, exits, and your local jurisdiction allows 3rd floors for residential. IRC doesn't necessarily require sprinklers in existing buildings (R313.2, the exception for existing buildings). But since you are changing occupancy from Business to Residential the interpretation may well be that you need sprinklers in any case, unrelated to the third floor thing. Residential sprinkler systems are somewhat controversial so that paragraph in the IRC is likely amended by your state or local jurisdiction.
 
Thanks, Sleepy and everyone else for your thoughts. This helped me sort through my own understanding and onto my next move which is a meeting with the code official and my architect and how to approach. Much appreciated.
 
R101.2 Scope. The provisions of the International Residential
Code for One- and Two-family Dwellings shall apply to
the construction, alteration, movement, enlargement,
replacement, repair, equipment, use and occupancy, location,
removal and demolition of detached one- and two-family
dwellings and townhouses not more than three stories above
grade plane in height with a separate means of egress and
their accessory structures.
 
You haven't indicated if this building is: a stand alone, zero lot line, meets all yard requirements?
Also, being an 1888, is it structurally compliant for a 3 story building?
 
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