We are developing a mixed use building with retail on the ground floor, office on the second and 9 levels of residential above. The retail has access at grade but uses the common loading dock and service corridor. The office and residential also share those elements but also share a common lobby, elevators and stairs. The entire building shares a single system for M+E. I am familiar with BOMA standards for retail and office and with Tarion standards for measuring residential, but am not sure to allocate the common areas referred to above. Would it be based on a proportional allocation based on areas? Please advise. Thanks