In the case of a lot where the maximum gross floor area limitation calculated pursuant to Subsection A above would permit a one-family dwelling having more than 16,000 square feet of gross floor area, the maximum gross floor area limitation applicable to such lot shall be 16,000 square feet. It is the intent of this provision that, notwithstanding Subsection A above, the gross floor area of a one-family dwelling shall not exceed 16,000 square feet under any circumstance.