No building permit shall be issued on any substandard lot, which lot was of record at the effective date hereof, unless said lot or a combination of existing substandard lots or parts of substandard lots equal fifty feet (50') in lot width and six thousand two hundred fifty (6,250) square feet of lot area. Combining of substandard lots or parts of substandard lots to provide the above minimum frontage and square foot area must be approved by the Zoning and Planning Commission and the board of trustees and a plat of resubdivision is required.