400 square feet (20' x 20') and larger: $0.29 per square foot, but in no case less than $120. Plus a 25% processing fee, but in no case less than $30.
Accessory buildings include storage buildings, detached garages, gazebos, detached patio structures, cabanas, etc., or any other structure that is an accessory use to the main structure on a single-family lot.
A building permit is required for any accessory building (garage, storage shed, etc.) that is larger than 20 square feet. Many neighborhoods have their own distinct rules for accessory buildings. Some of these rules are City Ordinances and some are private deed/HOA restrictions. The City will enforce City Ordinances, but it is the homeowner's responsibility to know and abide by private deed/HOA restrictions.
Storage buildings cannot be used as dwelling units (no one may live in the storage building).
The building must be built of typical building materials. Unpainted wood, tin, plastic, plain concrete blocks, corrugated metal, plastics, canvas, vinyl, or similar materials are not allowed.
The roof of an accessory building cannot be corrugated metal, plastic, or canvas. Roofs must be either composition shingles (if the roof pitch is at least 2:12), rolled roofing, built-up roof, metal panels type R, U, S-36, 7.2, or A, or other material allowed by the Building Official.
Accessory buildings on corner lots must meet the same setback requirements as the main structure (house). In most cases, a minimum 20-foot setback is required from the side property line.
Accessory buildings that are located behind the house must be a minimum 3 feet from side and rear yard property lines.
Accessory buildings that are between the house and the side property line must meet the setback requirements as set forth in either the Comprehensive Zoning or the Planned Development standards set for your subdivision; however, in most cases it would be 6 feet from the side property line.
Buildings larger than 144 square feet must be 6 feet from the house.
Buildings cannot have a wall height taller than 10 1/2 feet and cannot have an average height taller than 15 feet (unless the building is larger than 500 square feet).
Buildings larger than 200 square feet cannot have an exterior material of metal.
Buildings larger than 500 square feet must have an exterior finish that is similar to the main structure; they cannot have a wall height taller than 12 1/2 feet and cannot have an average height taller than 25 feet. Also, they are not allowed to be taller than the house.
Buildings larger than 600 square feet are only allowed if the size of the house and lot meet certain size standards.
Foundations (slab-on-grade or pier and beam) are required for accessory buildings that are 400 square feet and larger.
When the building is not attached to a normal foundation by its plates, tie-downs shall be required in each corner.
Utility and storage buildings that are 144 square feet or less in floor area and permitted as non-habitable spaces may be constructed on any type of slab, runner, or other device which transfers the weight of the building to the ground. Buildings that are larger than 144 square feet in floor area shall meet the following requirements:
All untreated wood in plates, runners, etc. should be no less than six (6) inches from the ground. Wood posts or poles embedded in the earth shall be treated wood.
All piers, whether of treated wood, concrete or masonry block, shall be spaced no more than eight (8) feet on center.
When the building is not attached to a normal foundation by its plates, tie-downs shall be required at each corner.
When the floor joists span a distance greater than what is allowed for the size of the joist used, intermediate beams will be required under the joists.
A one-story wood or metal frame accessory building not used for human occupancy and not over 400 square feet in floor area may be constructed with walls supported on a wood foundation plate.
Accessory buildings that are attached to the main structure or buildings that are 400 square feet and larger in floor area must have a foundation that meet the pier and beam or slab-on-grade requirements as specified by the City of Garland Building Inspections Department.