The rated wall option is the result of a new fire separation requirement in the 2012 North Carolina Residential Building Code, which is outlined in full HERE.
Under the new code, any home constructed less than 5 feet from the property line is required to have a 1-hour rated wall, with openings on no more than 25% percent of the surface. Any home constructed less than 3 feet from the property line is required to have a 1-hour rated wall, with NO openings (windows or doors) allowed.
This design change impacts more than just the wall construction, and could necessitate major interior floor plan alterations. But because a large number of approved and developed lots in Mecklenburg County allow homes to be constructed as close as 3′ from the property line, builders in these neighborhoods are often learning about the new firewall requirement as late as their framing inspection, and having to make the necessary changes in the field.
To address this issue, Mecklenburg County has implemented the following procedure:
On all new SF permit applications, they are now requiring the builder to include a PE survey or contractor letter saying the home will be built at least 5′ from the side and rear property lines. These permits will go through without any need for changes to the Master Plan.
Any permits submitted where the home will be built less than 5′ from the property line would have to go through a custom review, regardless of whether or not the County has an approved Master Plan on file. This will allow the builder to add the 1-hour rated wall option for approval with the permit.
REBIC supports this approach as a temporary fix to this problem, and is working with County Code Enforcement to try and identify a longer-term solution that will preserve the value of the Master Plan review process, which is intended to cover all possible design conditions for each plan.