Townhomes

[Woodrow]

How many connected townhomes before going to IBC? Code reference as well please. I am convinced that over 16 goes to commercial but I cant find anything.

 

[Yikes]

What state / jurisdiction is it located in?

 

[fatboy]

Unamended IRC would allow any number, just based on the unamended IRC text. Not speaking to any other codes or provisions.

I used to joke that you could build therm non-stop.

Nothing in the scope precludes that.

JMHO

R101.2 Scope. The provisions of this code 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 not more than three stories above
grade plane in height.

 

[Woodrow]

What state / jurisdiction is it located in?

South Carolina

 

[Yankee Chronicler]

How many connected townhomes before going to IBC? Code reference as well please. I am convinced that over 16 goes to commercial but I cant find anything.

That's probably because what you're looking for doesn't exist.

SC Residential Code:

R101.2 Scope
The provisions of this code 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 not more than three stories above grade plane in height.

[RB] TOWNHOUSE. A building that contains three or more attached townhouse units.

[RB] TOWNHOUSE UNIT. A single-family dwelling unit in a townhouse that extends from foundation to roof and that has a yard or public way on not less than two sides.

The definition doesn't create any upper limit. If it's two side-by-side dwelling units, it's a two-family dwelling structure. Three or more attached townhouse units-- with no upper limit -- is a townhouse structure.

 

[Joe.B]

One million.

No wait, one billion!

 

[steveray]

One million.

No wait, one billion!

Exactly what I was going to say....

 

[Yikes]

(Edit / update 8/23/24: I changed my mind - - see post #12.)

Woodrow, based on the responses above, When any single building one single townhouse or two attached townhouses = South Carolina Residential Code.
If you have multiple buildings, but each of those buildings only contains one single townhouse or two attached townhouses = South Carolina Residential Code.
https://up.codes/viewer/south_carolina/irc-2021/chapter/1/scope-and-administration#R101.2

​

Any other building that does not meet the definition above (such as containing 3+ dwelling units) = South Carolina Building Code.
https://up.codes/viewer/south_carolina/ibc-2021/chapter/1/scope-and-administration#101.2
Excerpt form 2021 SCBC:


If I had to guess where the number sixteen came from in your memory, I think the old Fair Housing Act Design Manual once referenced an example of how to apply FHA to a hypothetical 16-unit building. If so, that was not intended to establish a threshold number, it was just an example.

 

[mtlogcabin]

You are only limited by the size of the land you want to build them on.
In my part of the country that could easily be 10-20 miles long.

 

[mtlogcabin]

Over 16 units was also the threshold number used for requiring the installation of sprinklers

 

[redeyedfly]

Woodrow, based on the responses above, When any single building one single townhouse or two attached townhouses = South Carolina Residential Code.
If you have multiple buildings, but each of those buildings only contains one single townhouse or two attached townhouses = South Carolina Residential Code.
https://up.codes/viewer/south_carolina/irc-2021/chapter/1/scope-and-administration#R101.2

View attachment 14142​

Any other building that does not meet the definition above (such as containing 3+ dwelling units) = South Carolina Building Code.
https://up.codes/viewer/south_carolina/ibc-2021/chapter/1/scope-and-administration#101.2
Excerpt form 2021 SCBC:
View attachment 14143

If I had to guess where the number sixteen came from in your memory, I think the old Fair Housing Act Design Manual once referenced an example of how to apply FHA to a hypothetical 16-unit building. If so, that was not intended to establish a threshold number, it was just an example.

That would be different from any jurisdiction I have built townhomes in. The number of townhomes does not change which code you're under. Townhomes are single family attached. You can have 12 townhomes all attached and still be IRC. If you don't meet the definition of a townhome (at least two sides open to yard or public way and no stacking) then you are R-2 under IBC. You're ignoring the "and" in front of "townhouses" in the exception.

One billion attached townhomes, still IRC.

 

[Yikes]

That would be different from any jurisdiction I have built townhomes in. The number of townhomes does not change which code you're under. Townhomes are single family attached. You can have 12 townhomes all attached and still be IRC. If you don't meet the definition of a townhome (at least two sides open to yard or public way and no stacking) then you are R-2 under IBC. You're ignoring the "and" in front of "townhouses" in the exception.

One billion attached townhomes, still IRC.

Ah, coming back to sentence structure yet again:


Adding commas and words to help under stand our two different perspectives as to what nouns are being modified by the word "detached", redeyed fly, you are reading it as:

• Detached one- and two-family dwellings, and townhomes not more than three stories above grade plane...

I 've been reading it as:

• Detached one and two-family dwellings, and [detached] townhomes not more than three stories above grade plane...

And in context of the IRC requirements for separation walls where each townhome is structurally independent, with independent fire ratings, I am now inclined to agree with you that the intent of the code is that a billion townhomes would still be IRC.

 

[Paul Sweet]

Are these along the coast? I used to work for an architect who designed homes on the SC coast, and the FEMA requirements for raising them sometimes pushed them over 3 stories so they fell under the ICC instead of IRC.