Impervious calculations are the total area of the lot with a solid pad/ roof area that does not allow water to penetrate through the ground i.e., house foundation, driveways, porches, sidewalks, sheds, pergola, decks, patios and pool areas. Please note that the water surface of pools are calculated as 50% of the total area square footage. Any time a permit is being requested to extend, add on or create a solid base or solid roofed area to existing or additional structure, an Impervious Calculation worksheet must be included showing current solid areas or pavers and what is being added to existing. Each lot/ parcel has an Impervious surface percentage that can not be exceeded. Please check with the Planning & Zoning Department for what the impervious ratio is for a particular lot/ parcel.