Two family remodeled Fire separation?

[Buelligan]

Hi guys,

I have a 100+ year old two story structure being renovated to 2 one bedroom apartments, one unit on each floor. The owner removed everything down to the bare studs before obtaining his permit. He will be moving and/or removing some walls as well. So we consider this a remodel/alteration by 2015 IRC Apendix J Existing Building Code. (yes it is specifically adopted). I can not find any exceptions to the 1-hour floor-ceiling separation required by R302.3 Two-Family Dwellings. Would all of you require this as well or am I missing an exception somewhere?

I am also considering, based on age and non code construction, requiring a design professional (structural engineer) to evaluate the structure. AJ104 Evaluation of an Existing Structure The structure is a fairly large L-shape and the intent includes removing the large "wing" to just create a "box". I wonder how much this will change the integrity of the structure in regards to wind loads etc. Good question? or is that pushing my luck? Some opinions are welcome.

I attached the submitted plan set. Never mind the total lack of sufficient information on the "concept floor plan". I am requesting a more comprehensive set. I just need to make sure the separation requirement is correct on top of the other list of requirements I have.

Thanks!

 

[Francis Vineyard]

Clarify they are demolishing one of the attached single-family unit and converting the remaining single family to a 2-family unit?

If yes this would be a change of occupancy and the IRC administrative section 110.2 (if adopted) references Section 407 (see 407.1.1) & 408 of the IEBC (if adopted).

 

[Buelligan]

Clarify they are demolishing one of the attached single-family unit and converting the remaining single family to a 2-family unit?

If yes this would be a change of occupancy and the IRC administrative section 110.2 (if adopted) references Section 407 (see 407.1.1) & 408 of the IEBC (if adopted).

Well, first of all, the structure is 150yo, built in 1860. The main part contained a general store with a dwelling unit above, unused for decades. The "wing" was a two story single family home that was rented as a single apartment on the first floor with the second floor unused for many years. So this structure has been used as a single family dwelling for many years. Lots of unused space (75%+) but maybe used for storage, not sure. The new owner now wants to remove the larger part of the structure (the store and 2nd floor apt.) and "renovate" the remaining 2-story wing into a "Two Family Dwelling" with a one bedroom apt on each floor.
Because of the "extensive" renovations we feel the separation is required by code.

Does that clarify?

Appears 407 & 408 (not currently on any historic registries) would require both as well?

 

[Francis Vineyard]

I agree; especially since it's been gutted.

 

[steveray]

Very hard to retro a stacked 2 family....gutting helps, but if it is platform construction, that means the first floor holds up the second, so rate everything....Being that old, it might be balloon framed and be a little easier...

 

[JBI]

Absolutely require the evaluation by an RDP, best way to CYA.
The one hour horizontal assembly definitely needs to be supported by one hour construction.
There is no 'change of occupancy' in the published IRC Appendix J. Per definitions in Appendix J it is an Alteration that rises to the level of Reconstruction (see AJ501.3).
The IEBC is an approved alternative, but that may not work for this project very well as it will be an 'R' occupancy in IEBC (and a single family to a two-family would be an R-3 to an R-3, so STILL not a change of occupancy) and a Level 3 Alteration.
Generic language in AJ102.1 requires that it not become unsafe or dangerous as a result of the work, but fire separation provisions appear to only address side-by-side units, not over and under. Keep us posted on progress and outcome, please.
(on a personal note, I can see why NYS has modified this appendix in it's entirety...)

 

[Francis Vineyard]

Absolutely require the evaluation by an RDP, best way to CYA.
The one hour horizontal assembly definitely needs to be supported by one hour construction.
There is no 'change of occupancy' in the published IRC Appendix J. Per definitions in Appendix J it is an Alteration that rises to the level of Reconstruction (see AJ501.3).
The IEBC is an approved alternative, but that may not work for this project very well as it will be an 'R' occupancy in IEBC (and a single family to a two-family would be an R-3 to an R-3, so STILL not a change of occupancy) and a Level 3 Alteration.
Generic language in AJ102.1 requires that it not become unsafe or dangerous as a result of the work, but fire separation provisions appear to only address side-by-side units, not over and under. Keep us posted on progress and outcome, please.
(on a personal note, I can see why NYS has modified this appendix in it's entirety...)

I think everyone is on board to require the fire separation. Depending on whether the current code requires a 13D system could come into play.
However to further clarify a change of occupancy includes converting to a 2-family from a single family structure.

R110.2 Change in use.
Changes in the character of use of an existing structure shall not be made except as specified in Section 407 and 408 of the International Existing Building Code.

IEBC 407.1.1 Change in the character of use.
A change in occupancy with no change of occupancy classification shall not be made to any structure that will subject the structure to any special provisions of the applicable International Codes, without approval of the building official. Compliance shall be only as necessary to meet the specific provisions and is not intended to require the entire building be brought into compliance.

CHANGE OF OCCUPANCY. A change in the use of the building or a portion of a building. A change of occupancy shall include any change of occupancy classification, any change from one group to another group within an occupancy classification or any change in use within a group for a specific occupancy classification.

IBC [A] CHANGE OF OCCUPANCY. A change in the purpose or level of activity within a building that involves a change in application of the requirements of this code.

 

[JBI]

I stand corrected, thank you Francis.

 

[my250r11]

Absolutely require the evaluation by an RDP, best way to CYA.

Most definitely agree with this.

 

[Buelligan]

Thanks guys, the owner did not disagree either, for the most part anyway. LOL