Fire Wall Separation for Egress Stair?

Hi everyone,


I am working on a remodel for a replacement of an existing egress stairway and deck in the backyard (this is in San Francisco, R-3) of a house that abuts the neighbors exterior wall on the lot line. I have been going through the CBC 2010 reviewing chapter 7 for requirements on fire walls and looking at chapter 10 for egress requirements but am not clear if a fire wall is required to separate the deck from the exterior wall of the neighbor (see attached plan).  I am a bit at a loss as to what what the city will require and would like to clarify before going into CDs. 





Original Post

 "I am a bit at a loss as to what what the city will require..."


Why have you not simply asked the city what they require?   Certainly the city's response would be more 'reliable' to your immediate needs than anything we will tell you here. 


Far too often architects are reticent to have an informal/ongoing dialogue with plan checkers or BO's because they are viewed as adversaries.  That is unfortunate... there is no reason for this to be the case.  In a case like this (seeking opinions of outside parties) the result can mean you will move forward with CD's only to find later that the City has a different 'take', or some local/specific code adoptions that might affect how you proceed.


Treat your BO as a team member.  All BO's (like all of us) are happy to be of help when asked...  and actually appreciate being asked for their input.  It demonstrates to them that you value their opinion.  Forming a better relationship with your local BO can only be a positive development (for both you, the BO and your client).  Let's face it, sooner or later you are going to have to get their blessing of your design.  Why not do it now, in a proactive manner?

Hi there,


I absolutely agree with you...  The first thing I did was call the SFBD and I did speak with a plan reviewer.  Unfortunately he was rather annoyed with the question and responded, "I don't have time to teach you the code."  I understand without the plan it's tough to offer reliable input...  but it was still pulling teeth to get a little guidance.   I asked if it's possible to stop in and review before submitting, and he said no, I just needed to submit the plans and see what their comments were.  I am reaching out to people on this issue because I know of a local design-build firm that has successfully pushed back on fire walls and setback requirements for decks and egress stairs in backyards.  Apparently SF has a unique interpretation to this portion of code compared to other cities and some plan checkers are willing to work with designers/builders on reinterpreting it. (I don't think that will be the case here however).


I definitely don't see the building department as adversaries.  On the flipside the planning department was very friendly on answering some questions on setbacks and told me to just drop in to review before submitting.




I agree with Handler 100% as a start. 


You can also put in a call to the Building Official (meaning the boss, not the counter man).  Most BO's have a more cooperative attitude, acquired over time (and since he/she is the boss he/she does not have the same pressure on - to only look at submitted plans).


You've already made the key point - getting an interpretation up front is especially important in that you state SF has a 'unique' way of looking at the requirements.


If my first comments were a bit 'testy' and made poor assumptions about your process, my apologies.  Yesterday was a long day.


I would also add the following - although not directly as to whether the code requires the protection.  (I do agree with Handler's initial response, by the way.)


Consider that your primary objective is to serve your client.  Without the rated construction your client has an increased exposure to damage and/or physical injury or death in either of two circumstances:  a)  a fire in the adjoining building cheek-to-cheek with your new deck/stair spreading to your building (it does not take long for wood to 'go up' when there is zero separation from a source);   b)  a fire in your own building that spreads to the adjacent structure, causing damage/injury/death and not covered by insurance because the carrier will argue the design was deficient (the spread of fire was both foreseeable and predictable);   c) a fire involving both structures renders the new exit stair unusable due to flames and/or smoke, preventing the occupants in your building from reaching safety.


Even if the City for some reason allowed you to build without a rated deck/stair (which I doubt), I would encourage you to discuss the practical impacts with your client... and I would at a minimum suggest using non-combustible materials for the entire new work.


An insurer may also not want to take on the risk of this building with the new non-rated construction that presents an increased risk - or might increase premiums for coverage.


Whether to proactively seek safer solutions or not is a question that can go beyond what the code minimum requires - and sometimes requires that you go to battle with your own client (in his/her own best interests, as well as yours, even though initial construction costs may be greater).


I hope you get it straightened out with the BO, but would also encourage sitting with your own client and discussing merits and options.   

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