1060.050: - BUILDING STANDARDS — Corcoran Zoning Code

Subd. 1. Building Type and Construction.

A. General Provisions.

Quality. Buildings in all zoning districts shall maintain a high standard of architectural and aesthetic compatibility with surrounding properties to ensure that they will not adversely impact the property values of the abutting properties or adversely impact the public health, safety and general welfare.
1. Additions or Alterations. When an expansion of an existing structure is proposed, the existing facade shall be upgraded so that 25% or more of the existing structure conforms to the exterior building material requirements as outlined herein, unless otherwise approved by Conditional Use Permit. The improvements shall be concentrated on the side facing the public road and/or the side facing an area zoned for residential use.

B. Residential District Standards.
1. All residential structures shall be finished with materials comparable in grade and quality to the following:
  - a. Face Brick.
  - b. Natural stone or cultured stone.
  - c. Wood, provided the surfaces are finished for exterior use and wood of proven exterior durability is used, such as cedar, redwood, cypress.
  - d. Stucco or EIFS.
  - e. Vinyl siding.
  - f. Fiber cement siding.
  - g. Other materials deemed appropriate and subject to approval by the Zoning Administrator.
2. Roof Material. Dwellings shall have an earth covered, asphalt shingles, wood shingled (including shakes), concrete, clay or ceramic-tiled roof. In addition, metal roof coverings may be allowed by approval of the Zoning Administrator via a Certificate of Compliance, provided they:
  - a. Meet the standards adopted by the Minnesota State Building Code,
  - b. Have concealed fasteners,
  - c. Are high quality commercial thickness/weight,
  - d. Have been treated with a factory applied color coating system against any fading or degradation.
3. All residential structures shall have permanent concrete or wood foundations, which comply with the Minnesota State Building Code and which is solid for the complete circumference of the house.
4. All residential dwellings must be built in conformance with the Minnesota State Building Code.
5. All residential dwellings shall have roof overhangs which extend a minimum of one (1) foot from the exterior wall of the structure.
C. Non-Residential District Standards.

Finishes. Exterior building finishes in all districts except the CR district shall consist of materials comparable in grade and quality to the following:
- a. Face Brick.
- b. Natural stone or cultured stone.
- c. Decorative concrete block or integral colored block.
- d. Cast in place concrete or pre-cast concrete panels.
- e. Wood, provided the surfaces are finished for exterior use and wood of proven exterior durability is used, such as cedar, redwood, cypress.

f. Curtain wall panels of steel, fiberglass and aluminum (non-structural, non-load bearing), provided such panels are factory fabricated and finished with a durable nonfade surface and their fasteners are of a corrosion resistant design. Up to 20% of any wall surface may consist of the materials outlined herein (excludes overhead doors).
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- i. In the CR zoning district, 50% of any wall surface (excludes overhead doors) may consist of curtain wall panels of steel, fiberglass and aluminum (non-structural, non-load bearing), provided such panels are factory fabricated and finished with a durable non-fade surface and their fasteners are of a corrosion resistant design. 
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- g. Glass curtain wall panels.
- h. Stucco or EIFS.
- i. Fiber cement siding.
- j. Other materials deemed appropriate and subject to approval by the Zoning Administrator.

Roof Materials. For all non-residential structures roof materials shall be reviewed as part of the site plan. Acceptable roofing materials include asphalt shingles, wood shingles (including shake), concrete, clay or ceramic tile roofs. Metal roofs with a pitch greater than 2:12 shall not be permitted except as provided below:

a. Color samples shall be provided for review and approval by the City Council as part of the site plan review.
b. Metal roof coverings may be allowed for the above mentioned circumstances, provided the following conditions are met:
- i. Meet the standards adopted by the Minnesota State Building Code,
- ii. Have concealed fasteners,
- iii. Are high quality commercial thickness/weight,
- iv. Have been treated with a factory applied color coating system against any fading or degradation.
D. Accessory Buildings.
1. Accessory buildings shall comply with the standards identified in Section 1030.020 of this Ordinance.
2. Accessory buildings shall have roof overhangs which extend a minimum of one (1) foot from the exterior wall of the structure.
3. All accessory buildings, including agricultural buildings with metal siding and/or roofing may be allowed by approval of the Zoning Administrator via a Certificate of Compliance, provided they:
  - a. Meet the standards adopted by the Minnesota State Building Code.
  - b. Have been treated with a factory applied color coating system against any fading or degradation.
E. Exceptions to the provisions of this Section may be granted as a conditional use permit subject to the process outlined in Section 1070.020 and provided that:
1. The proposed building and material maintains the quality, durability and value intended by the Ordinance.
2. The proposed building is compatible and in harmony with other existing structures within the district and immediate geographic area.
3. The provisions of Section 1070.020 are considered and determined to be satisfied.

Subd. 2. Prohibited Materials. Prohibited materials include face materials that rapidly deteriorate or become unsightly such as unfinished/non-pigmented structural concrete block, galvanized metal, unglazed structural clay tile or common or back-up quality brick.

Subd. 3. Number of Buildings. No more than one principal building shall be located on a single family residential lot, except in the case of operating farms as provided for herein. No more than one principal building shall be located on a multiple family residential lot or non-residential lot, except by conditional use permit. The term principal building shall be given its common, ordinary meaning as defined in Section 1020.020 of this Chapter.