LYNN – The Mayo Group is requesting city permission to increase the number of residential condominium units inside its building at 24 Mount Vernon St. from 32 to 49.The project that transformed the former industrial building into market-rate condos was completed last month and the units are now for sale. The Boston-based Mayo Group added two stories to the building to increase the project’s potential. Some of the units were relatively large in terms of overall living space and could be made smaller, yet adequate, according to the developers.City Clerk Mary Audley said the Mayo Group has filed a petition with the City Council asking that the project’s special permit be amended so that the building interior layout can be configured to accommodate the additional units. A public hearing has been scheduled for Tuesday, Oct. 9 at City Hall.Local developer Andrew Perkins originally began the project at 24-68 Mount Vernon St. On July 24, 2004, the City Council issued Perkins a special permit to add a new fourth and fifth floor and to convert the second, third, fourth and fifth floors into condominiums. Perkins later sold the property to the Mayo Group.The Mayo Group wants to add 17 condominium units within the existing footprint by redesigning the layout currently shown on construction plans, according to the application on file at City Hall.The goal of the change is to make the condos more efficient, cost-effective, and more appealing to current or prospective residents. According to the application, Mayo Group is basing its decision on its experience marketing two residential projects in downtown Lynn over the past three years.According to the Mayo Group, the additional units would impose no substantial burden upon the city for services while increasing local real estate tax revenue.