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two duplexes or a four plex

( ~ ~ ~ ~ )

cda,

Global Warming is no longer the politically correct term.

Nowadays, the Spin-meisters are using the term "Climate Change" to

lubricate their agendas.........Just saying...

( ~ ~ ~ ~ )
 
& = = = &

Well, this OP has gotten off-track and deep in to the weeds.

I'm going to eject now, before I flame out.

See ya... :cool:

& = = = &
 
FIRE SEPARATION DISTANCE. The distance measured

from the building face to one of the following:

1. To the closest interior lot line; or

2. To the centerline of a street, an alley or public way; or

3. To an imaginary line between two buildings on the lot.

The distance shall be measured at a right angle from the

face of the wall.

R302.1 Exterior walls. Construction, projections, openings

and penetrations of exterior walls of dwellings and accessory

buildings shall comply with Table R302.1(1); or dwellings

equipped throughout with an automatic sprinkler system

installed in accordance with Section P2904 shall comply

with Table R302.1(2).

TABLE R302.1 EXTERIOR WALLS

EXTERIOR WALL ELEMENTMINIMUM

FIRE-RESISTANCE RATING		MINIMUM FIRE SEPARATION DISTANCE
Walls(Fire-resistance rated)1 hour-tested in accordance with ASTM E 119 or UL 263 with exposure from both side< 5 feet

"The exterior rated walls should be tested in accordance with either ASTM E 199 or UL 263. This is not intended to limit fire-resistance-rated assemblies solely to the test criteria contained in these standards. Section R104.11 still allows the building official to approve alternative fire-resistance methodologies, such as those described in Section 703.3 of the IBC. This would still allow a builder to use acceptable engineering analysis, calculations in accordance with Section 721 of the IBC or prescriptive assemblies permitted by Section 720 of the IBC as alternatives tot he standards contained within the code."

R104.11 Alternative materials, design and methods of construction and equipment. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code. Compliance with the specific performance-based provisions of the International Codes in lieu of specific requirements of this code shall also be permitted as an alternate.
 
FV & Retire;

Appears the argument for detached duplex is still alive if each is a separate structure. See post #2 & #15

If two hr party wall on common foundation then "detached" is not provided

Retire; do you know the actual construction condition at "2hr" as described in your OP?
 
I have not seen the building myself but the builder tells me he has a two hour fire wall with two apartments on each side. Assuming that is correct;

I would say the building does not qualify for construction under the IRC because the two units on each side of the fire wall are not detached and therefore not exempt from the IBC per 101.2 exception.

So, per the IBC we have two separate buildings, separated by a fire wall. Each building contains only two dwelling units which by definition is still an R-3. It is not a duplex and not a townhouse but still an R-3. A two dwelling unit building on each side. Not an R-2 or a 4-plex.

Make sense?
 
A townhouse is a single dwelling unit and we have two units on each side with a 1 hour separation between.

Not a townhouse because not one dwelling,

Not a duplex because not detached

R-3 Buildings that do not contain more than two dwelling units.
 
retire09 said:
A townhouse is a single dwelling unit and we have two units on each side with a 1 hour separation between.Not a townhouse because not one dwelling,

Not a duplex because not detached

R-3 Buildings that do not contain more than two dwelling units.
Click to expand...
Add another layer of Sheetrock and divide into individual units ?? So there are town houses?
 
Per the federal housing guidelines, accessiblity is required if this is an IBC residential building

"Covered multifamily dwellings" or "covered multifamily dwellings subject to the Fair Housing Amendments" means buildings consisting of four or more dwelling units if such buildings have one or more elevators; and ground floor dwelling units in other buildings consisting of four or more dwelling units. Dwelling units within a single structure separated by firewalls do not constitute separate buildings.
 
The IBC is a very specific about Fire Walls and their construction. I would bet the construction meets the definition of a Fire Barrier and not a Fire Wall as defined by the IBC therefore they would not be separate buildings and an R-3

See Section 706.2, 706.5.1, 706.5.2, 706.6 and possibly 706.6.1
 
So 101.2 exception literally allows the use of IRC if the two-family dwelling exterior walls are against one another but need to use IBC if constructed with a common wall for separate buildings?
 
jdfruit said:
Wow! Dude! no accessibility or structural review. Who does the code enforcement for structural and accessibility?
Click to expand...
Gets the polar bear "seal" of approval. Unless it needs a special "yak inspection"

""""""Unfortunately almost always true except in deferred jurisdictions. The deferred jurisdictions are most but not all of the larger cities. The smaller communities and remote areas are regulated only by the State. The State does a limited plan review but few or no inspections during construction. They issue a plan review approval but no permit or certificate of occupancy. With a plan review required, but no progress inspections they have no way of knowing if all plan requirements were provided in the construction. It's dysfunctional but the best they can do under the current structure.

I personally feel that plan review is of little value without proper progress inspections."""""
 
A fire wall must start at the lowest point (basement floor or slab on grade) and extend full height uninterrupted through or to the roof deck. Many, many people, DP's and Contractors as well as John Q. Public use the term fire wall waaaaay too often and for the wrong assembly more often than not.

The building in the OP may well have 2 two dwelling unit buildings within one structure properly divided by a fire wall and regulated as R-3 under the IBC, but it is not 2 detached two-family dwellings within the context of the IRC.
 
jdfruit said:
Wow! Dude! no accessibility or structural review. Who does the code enforcement for structural and accessibility?
Click to expand...
It is handled by the fire division. They are not concerned about trivial things such as accessibility or structural concerns. Sprinklers cover all of that
 
Only detached one and two family and townhouses are exempt. This is an attached two family and therefore technically is not exempt.

But it is still two R-3 buildings if the fire wall is built correctly.
 
TOWNHOUSE. A single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof and with a yard or public way on at least two sides.

I have what is essentially two duplexes attached being called "Villas". Single story dwelling units on a slab. Each unit is on a separate lot and has it's own front and back yard. each unit is separated by a 2-hour fire wall. Not one wall separating the "duplexes" but a full 2- hour wall between each unit.

Does this not meet the definition of townhouse pasted above?

I am requiring a sprinkler system per 313 and with that, could they not build a 1-hour "common wall" under the following exception?

R302.2 Townhouses. Each townhouse shall be considered a separate building and shall be separated by fire-resistance-rated wall assemblies meeting the requirements of Section R302.1 for exterior walls.

Exception: A common 1-hour fire-resistance-rated wall assembly tested in accordance with ASTM E 119 or UL 263 is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be installed in accordance with Chapters 34 through 43. Penetrations of electrical outlet boxes shall be in accordance with Section R302.4.
 
Bulligan,

The duplex must be detached or constructed with separate exterior walls to be allowed under the IRC, if constructed with a common or shared wall it must be constructed in accordance with the IBC.

Commentary; "(Duplexes, buildings with two dwelling units, must be detached from other structures in order to be regulated by the IRC.) A duplex attached to another duplex would be required to comply with the code and be classified as Group R-2 or R-3, depending on the presence of fire walls."
 
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