At least 75 percent of the total exterior wall area of all residential structures in the AG Agricultural and the R-1, R-2, R-3 Residential districts, excluding doors, windows, breezeways and courtyards, of single-family residential structures, regardless of height or number of stories, shall be constructed of masonry construction as defined herein. Exterior walls facing a porch or patio shall be included in the total wall area calculation for purposes of this article. The exterior portion of a chimney for newly constructed single-family structures or additions to existing dwellings shall be constructed of 100 percent masonry materials.

The remainder of the wall area may be constructed of non-masonry materials as defined herein, provided that no single elevation shall be less than 50 percent masonry construction, except walls or portions thereof on a porch, patio, courtyard or breezeway may be constructed of non-masonry materials. Damage-resistant exterior insulation finishing systems (EIFS) may be installed as a non-masonry material above a height of eight feet.

Where a second-story exterior wall of a single-family residential structure is offset a minimum of three feet from the plane of the first-floor exterior wall below, or a dormer window is offset a minimum of one foot from the plane of the first-floor exterior wall below, the wall of the offset portion shall be excluded from the wall area calculation for purposes of this section.

Roofs shall be constructed of metal, concrete or clay tile, natural or manufactured stone, or laminated asphalt shingles of at least 300 pounds per square. Wood shingles are expressly prohibited.

Where non-masonry construction is permitted, hardboard siding material is prohibited except as provided in this article.

Where a garage is converted for use as living space or converted into space other than vehicle storage space, the conversion shall be constructed in conformance with the residential exterior construction standards herein and shall be architecturally compatible with the principal building as determined by the chief building official, or designee.

Materials used in the recladding of existing residential structures must be architecturally compatible with the principal structure including all new and existing trim, architectural appendages, windows and doors as determined by the city manager or designee.

Nothing contained in this article shall require any change in the plans or construction of a single-family residential structure located on a platted lot of record to conform to these standards for which a building permit has been issued, or a single-family residential structure for which a substantially complete application for a building permit was accepted by the city manager or designee prior to the effective date of this chapter, provided, however, such single-family residential structure shall comply with all applicable ordinances of the city in effect on the date of such application was filed and the building permit is issued within 30 days thereafter.

Lots in a single-family residential zoning district may include the customary accessory buildings provided there is a main building located on the property.

Accessory buildings less than 400 square feet in size may be constructed of masonry or non-masonry materials or a combination.

Accessory buildings of 400 square feet or more, including carports with a covered area of 400 square feet or more between the support poles or columns, may be constructed of masonry or non-masonry materials. The appearance of the accessory building shall conform to the exterior appearance of the main building in terms of wall color, trim color, roof pitch and roof color.

Carports shall be permitted provided they are used primarily for the shelter of motor vehicles and not for the storage of materials or items other than vehicles.

A private garage is permitted to accommodate no more than five automobiles in the R-3 or R-4 zoning districts.

Barns of any size as defined herein may be constructed of durable non-masonry materials in accordance with the Bulverde building code.