Combining allowable areas vs. Fire separation

[Code]

Happy Friday All!

I have some densely located live/work buildings in a new development coming in. No internal property lines. Wondering if anyone has allowed/designed detached buildings without fire separation distance, or exterior rated assemblies, if the aggregate area of the buildings is under what is described in 503. If not, what threshold do you use for determining separate structures? Is a trellis attached at the roof line enough, or would it have to be something more substantial?

 

[Francis Vineyard]

To further clarify the provision of 503.1.2 (2012) for separate buildings considered as one building and the exception to 705.3 the commentary states " the exception permits two buildings on the same lot to be exempt from Section s 705.5 (exterior wall fire-resistance rating) and 705.8 (openings) when considered as one building. However the provisions of Sections 705.8.5 and 705.8.6 would still apply, since a need exists to restrict fire spread between stories within a building. Although not specifically identified in the exception, Section 705.11 would not apply, since it is dependent on the exterior wall being required to have a fire-resistance rating in accordance with Section 705.5, which relates to measurement of FSD.

 

[cda]

A class on live work would be nice

 

[Code]

To further clarify the provision of 503.1.2 (2012) for separate buildings considered as one building and the exception to 705.3 the commentary states " the exception permits two buildings on the same lot to be exempt from Section s 705.5 (exterior wall fire-resistance rating) and 705.8 (openings) when considered as one building. However the provisions of Sections 705.8.5 and 705.8.6 would still apply, since a need exists to restrict fire spread between stories within a building. Although not specifically identified in the exception, Section 705.11 would not apply, since it is dependent on the exterior wall being required to have a fire-resistance rating in accordance with Section 705.5, which relates to measurement of FSD.

Francis- Thanks for the response! That makes sense. Either get it the right distance away, or use 705.11. They're claiming that two neighboring jurisdictions have allowed the design without ratings. I've asked for the names of the projects to go out and take a look. I'm curious if the % of protected and unprotected openings comply with 705.8.

 

[Francis Vineyard]

Deleted Duplicate answer; see next post.

 

[Francis Vineyard]

Depending on the IRC edition 101.2;

2015 & 2018 live/work units only in townhouses.

Permitted in single family dwellings in 2009 & 2012 both 6th & 12th printing. Could zero rating and unlimited opening where six feet apart.