Fire sprinkler needed for 4 story duplex?

[Julia XA]

I have a client who wants 2 four story duplexes (2 separate structures with 2 dwelling units each) with garages on the ground floor. Is it necessary to have fire sprinklers? The occupancy is R2. There will be other 3 story townhouses on the same site but not near the proposed 4 story duplexes. Construction to be wood framed, concrete slab on grade. IBC will be 2015 by the time these go online.
Thanks
Julia.

[Jerry Peck - Codeman]

What is the code in effect in your area?

If the ICC codes are in effect, or are the base codes for your areas codes, then the Residential Code only applies to three stories and less, the Building Code would apply to four stories and higher, and, yes, sprinklers would be required.

Those four story dwelling would no longer be considered as duplexes. They would either be condo buildings (which are constructed the same as apartment buildings) or attached dwelling units.

Are the buildings 'one building on the same lot', or are the buildings ''separate but attached buildings on separate lots' (i.e., have a lot line between the buildings, which would require a fire-wall)?

[Julia XA]

Currently the code in effect is ICC 2009 but it will be switching to 2015 in a few months.

I see that sprinklers are required in 4 story R-2 buildings in group V however I thought there were some exceptions if the overall floor area of each building is under a 12,000 sf. But I cannot confirm this.

The buildings are on the same site without separate lot lines. Currently we are in the planning stages.
We are proposing two 4 story duplexes (so 4 dwelling units) and one 3 story group of 8 townhomes (so 8 dwelling units)

All the units would have an enclosed garage on the ground level.

Total dwelling units on the site would be 12 in 3 separate buildings. Area separation is not an issue as the buildings will be spaced at minimum 20 feet apart.

Thanks,
Julia

[Jerry Peck - Codeman]

Being as this project is in the planning stages, and that the code will be changing to the 2015 ICC codes before the permit application date, I will reference the 2015 IBC/IRC as the applicable code(s).

First, we need to determine which code is applicable, and this is easier than it seems while also being not as easy as it seems:
- From the 2015 IBC:
- - 101.2 Scope.
- - - The provisions of this code shall apply to the construction, alteration, relocation, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures.
- - - - Exceptions: Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories above grade plane in height with a separate means of egress, and their accessory structures not more than three stories above grade plane in height, shall comply with the International Residential Code.

- From the 2015 IRC:
- - 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 one- and two-family dwelling and townhouses not more than three stories above grade plane in height with a separate means of egress and their accessory structures not more than three stories above grade plane in height.
- - - - Exceptions:
- - - - - 1. Live'work units located in townhouses and complying with the requirements of Section 419 of the International Building Code shall be permitted to be constructed in accordance with the International Residential Code for One- and Two-Family Dwellings. Fire suppression required by Section 419.5 of the International Building Code where constructed under the International Residential Code for One- and Two-family Dwellings shall conform to Section P2904.
- - - - - 2. Owner-occupied lodging houses with five or fewer guestrooms shall be permitted to be constructed in accordance with the International Residential Code for One- and Two-family Dwellings where equipped with a fire sprinkler system in accordance with Section P2904.


From the 2015 IBC:
- Townhouse. A single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from the foundation to the roof and with open space on at least two sides.

From the 2015 IRC:
- Townhouse. A single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from the foundation to the roof and with a yard or public way on not less than two sides.

Some codes contain the following amended wording in the above definitions, and that wording can change which code is applicable to the project: " ... in a group of three or more attached units with property lines separating each unit ... "

Which code are you designing under at this time?

Note:
I have submitted a question to ICC to verify how the ICC wording differentiates townhouses - only at 'not more than three-stories'/'more than three-stories', or if there is an implied differentiation having a lot line or on one lot.

[Julia XA]

I have been advised that I would be designing under the IBC (not the IRC) because of the total number of units on the site and the fact that they will be rentals and not individually owned. So we would fall under the 2015 IBC.

Interesting then about town houses being defined as 3 units or more.

Obviously my 8 gang units would be considered townhouses, but those are only 3 story.

So my question about the 4 story "duplexes" is still in question w/r/t fire sprinkler requirements. I assume they will be required because they are 4 story, but have not been able to get a definitive answer. The code mentions 12,000 sf total for Type 5A and 7,000 sf total for Type 5B but it is not clear to me whether this is an exception to the sprinkler requirement if we are under those totals in each building.

Thanks for inquiring about this.

[Jerry Peck - Codeman]

[Julia XA]

Wow thank you so much. I feel more confident now telling my client that he has to sprinkler the buildings no ifs, ands ... And he can do his cost feasibility with this information.

Thanks again.
Julia