Subject property is one unit of a duplex - Each owner is responsible for their own section of the roof.
Subject property has a properly executed and final inspection to replace their half of the roof (2007)- the neighbor has not - Original 1993 roof.
We all know the roof shape question involves the entire structure - How say you regarding question 2 - FBC credit or no?
If you are doing the mit for the single unit. I would give them credit based on the fact that you are providing that unit number and not all units.
The pictures should give the insurance company a clue. If you want add a note to your form that points out the facts. Ie., unit roof is 2007 and adjacent roof is 1993.
That is just how I would handle it. IMHO
We all know they may sustain damage because the old roof may peel some of the new roof. I would compel my neighbor to update his roof.
Hope that helps
Thanks John, - I was hoping you would provide some insight
Anytime
I would agree with John. We typically provide a roof sketch and draw a red line where the units meet. As John said make sure you put the unit number to specify your inspection is for that unit only.
You should do only what is asked on the form. Just like I always try to tell everyone. Nothing more ever… Any of your other opinions will likely hurt your customer. Include picture and the correct answer for question 2 for the unit you are inspecting that is it. Roof sketches are not required and should not be done.
I agree with Mike on this.
I read and agree with the commments made prior to my posting this response but have to ask? what is your evaluation of the tie in between the units and how long would you expect it to remain leak free? This is a case where the nieghbor controls the destiny of the owners financial security.
I agree with Mike, as we run into this all the time down here in Hollywood. Report on the side you are there to evaluate.
Question though, does this unit have a firewall all the way up to separtea the units or is it a continuos opening above both?
There is a 5/8ths gypsum firewall through the attic
And for the record - no, I don’t include sketches of the dwelling (unless State Farm)
I don’t do it for anyone. Why do you for State Farm?
Let me guess some dumb a-s agents idea 
No - The underwriters require it to illustrate a hip roof when there is a combination of shapes - to show that the gable portion is less than 10%.
And yes - I do choose to go the extra mile to ensure that the customer gets credits that they deserve.
Good luck to ya.
I hope you are ready to go the extra 10 miles because this new form has been written by complete idiots.
You know what they say - A horse designed by committee is called a camel!
woooooosh
That one just went over my head.
I have never heard that expression before 
I still have not figured it out.
Look at a profile of a horse - nice and streamlined - now look at a profile of a horse designed by committee (that would be the camel) - All f***ed up!!!
I see the light and agree.
All Fu-ked up.
The predominant roof covering is defined as 50.01% of the total surface area of the structure. If no firewall extends above the roof line then the roof covering over the adjacent neighbors dwelling must be taken into consideration. If a firewall does in fact exist above the roof line then you will have your subject’s roof covering ONLY to consider.
The 50% rule is not actually defined anywhere, but rather interpreted that way. According to that interpretation, I would agree with that take on this scenario.