5-20-70 Measurement of Floor Area

(b) Roof and Deck Overhangs

• The floor area of a building, or portion of a building, not provided with surrounding exterior walls shall include the area under the horizontal projection of roofs or floors, when the roof or floor exceeds eight (8) feet. These architectural projections are exempt for eight (8) feet of the perimeter of each story of the structure. This exemption cannot be used to transfer space between floors. Roof and deck overhangs greater than eight (8) feet may only be converted to enclosed interior areas when the resulting floor area does not exceed maximum floor area that would otherwise be applicable to the property under Table 5-1.

(c) Decks, Balconies, Stairways and Similar Features

• Structures that exceed thirty (30) inches above natural or finished grade, and that are not covered by a roof or architectural projection from a building, are exempt from floor area for up to fifteen (15) percent of the approved floor area for the subject parcel or lot. Any areas in excess of fifteen (15) percent shall be counted toward floor area. Decks, balconies, stairways, and similar features with a horizontal projection greater than eight (8) feet may only be converted to enclosed interior areas when the resulting floor area does not exceed maximum floor area that would otherwise be applicable to the property under Table 5-1.
• Pergolas and open shade structures shall be considered part of the fifteen (15) percent of the approved floor area for decks, balconies, stairways, and similar features as specified above, so long as the following criteria are met: Overall height cannot exceed twelve (12) feet above finished or existing grade, whichever is most restrictive. At least seventy (70) percent of the area of such structures shall be open to the sky. There shall be no more than two (2) layers of structure above the column capitals. Principal beams shall be a minimum of ten (10) feet on center and have a maximum dimension of six (6) inches in width and twelve (12) inches in depth. Secondary beams shall be spaced at a minimum of twenty-four (24) inches on center and have a maximum dimension of four (4) inches in width and ten (10) inches in depth. There shall be no walls. The doubling of beams over the columns shall be permitted.

(d) Crawl Spaces

1. A Horizontal Crawl Space means an area below the first usable floor of a building or portion of a building, excluding decks, patios and terraces. Horizontal Crawl Spaces are exempt from floor area calculations when less than five (5) feet six (6) inches in height. Horizontal Crawl Spaces do not exceed the footprint of the exterior walls of the structure above, except that crawl spaces may be detached from the principal structure when used for exterior uses such as jacuzzis, spas, hospitality bars, water features, sprinkler systems, and pool mechanical areas. Such Crawl Spaces shall be no larger than necessary to accommodate necessary mechanical equipment and may not be used for other uses.
2. A Vertical Crawl Space means an enclosed, unfinished, and non-habitable area that may exceed five feet six inches (5’6”) in height and is located between the exterior of a foundation wall and the surface of the finished grade of a vertical or nearly vertical slope, which slope is retained by an engineered system which requires a separation between the foundation wall and the surface of the finished grade of the slope.

Vertical Crawl Spaces shall be exempt from floor area calculations, provided they comply with the following:

• (a) That the design is supported by an engineering/geologic study approved by the Community Development Department, which requires a separation between an engineered system and the exterior wall; and
• (b) The horizontal dimensions measured from the base of the exterior wall to the engineered system does not exceed six feet six inches (6’6”;) and
• (c) The area shall remain unfinished and contain no hard floors; and
• (d) The area shall be limited to containing non-spark producing mechanical, plumbing, electrical, telephone, cable, audio, and water systems. Storage shall be prohibited; and
• (e) Access to the area is limited to the dimensional requirements necessary for removal and repair or replacement of systems equipment; and
• (f) The Vertical Crawl Space may be covered at the top with a waterproof structural lid that does not have any habitable enclosed space above; and
• (g) The height of the Vertical Crawl Space shall not exceed twenty-five feet (25’.)

(e) Attic

• Attic means an area between roof framing and the ceiling framing of the room(s) below. Attics are exempt from the calculation of floor area when less than five (5) feet six (6) inches in height.

(f) Gas Station Canopies

• Up to one thousand (1,000) square feet of gas station canopy shall be exempt from the calculation of floor area for any approved gas station.

(g) Additional Provisions for Zone Districts within the Urban Growth Boundary Area Subject to Floor Areas Ratios

1. Exempt Below Grade Spaces for Principal Single-Family and Duplex Residences
   • For the R-15, R-15A, R-30, and AR-2 zone districts within the Urban Growth Boundary Area, spaces below grade shall be exempt from Floor Area calculations for up to a maximum of four thousand (4,000) square feet, and in the R-15B zone district, as provided in Note 10 of Table 5-1.B, provided such spaces comply with a-h below:
     • (a) Exempt below grade spaces are located below both the natural and finished grades. If any part of the below-grade space is exposed above natural or finished grade (such as walk-out basement, walls or courts) the entire below-grade area shall be included in the floor area calculations. Exempt Below-grade spaces are no greater than twenty (20) feet in depth and no more than a single story. For purposes of this definition, “story” shall mean that portion of a building included between the upper surface of a floor and the upper surface of the floor next above.
     • (b) Exempt below grade spaces are accessed only by stairway or elevator from the story directly above, or through a door from a garage adjacent to the below-grade area.
     • (c) Exempt below grade spaces are no greater than twenty (20) feet in depth and no more than a single story. For purposes of this definition, “story” shall mean that portion of a building included between the upper surface of a floor and the upper surface of the floor above.
     • (d) Exempt below grade spaces do not contain doors to the exterior of the structure.
     • (e) Exempt below-grade bedrooms are allowed no more than one (1) egress window per bedroom. Exempt below grade spaces that contain no bedrooms are allowed only one egress window. When below grade egress is achieved through one or more below grade bedrooms, no additional egress shall be provided. Egress window well size shall not exceed the minimum allowed by the International Building Code/International Residential Code.
     • (f) Habitable exempt below-grade spaces may be provided with aggregate glazing area of not more than eight (8) percent of the habitable area of the room. For purposes of this exemption, “habitable” shall mean a space in a building for living, sleeping, eating or cooking. Unfinished basements shall be considered habitable spaces. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas shall not be considered habitable spaces. Window wells for natural light have a maximum dimension of three (3) feet from the exterior wall. The maximum window well width shall be no more than the width of the window. Skylights and bay window-like glazing are prohibited in below grade spaces.
     • (g) Foundation walls for exempt below-grade spaces may be exposed above natural and finished grade to the minimum degree required by the IRC pertaining to foundation design.
     • (h) Up to ten (10) percent of any particular below-grade wall surface may extend above natural grade so long as the finished grade covers the wall surface that would otherwise be exposed.
     • (i) Garages up to seven hundred and fifty (750) square feet may be incorporated into below-grade space and shall not affect this exemption as long as the only sections of building so exposed are directly related to the garage structure.
     • (j) Floor area below natural and finished grade which exceeds the four thousand (4,000) square foot exemption shall count toward the calculation of allowable floor area.
2. Garages and Carports
   • For the purposes of calculating floor area ratio and allowable floor area for a lot where the principle use is single family residence, garage and carport floor area shall be exempted up to a maximum of seven hundred fifty (750) square feet. On a lot which contains a duplex, garage and carport floor area shall be exempted up to a maximum of one thousand (1000) square feet. All garage or carport space in excess of the exempted areas shall be included as part of the residential floor area calculation. When an existing legal single-family or duplex dwelling exceeds the allowed floor area, the exempt garage space shall be reduced by subtracting the excess floor area from the exempt garage space.

(h) Additional Provisions for VC and VR Districts

• In the VR and VC zone district, floor area is measured pursuant to a-e above except as noted below.
• In the VC and VR zone districts only: Spaces below natural and finished grade are exempt from floor area calculations up to a maximum of nine hundred ninety-nine (999) square feet of floor area. Floor area below grade that exceeds the nine hundred ninety-nine (999) square foot exemption shall count in the calculation of floor area. To be exempt from floor area, below grade areas must meet the following conditions:
  1. The pergolas and open shade structure allowance in (c) (2) above is not available.
  2. Spaces below natural and finished grade are exempt from floor area calculations up to a maximum of nine hundred ninety-nine (999) square feet of floor area. Floor area below grade that exceeds the nine hundred ninety-nine (999) square foot exemption shall count in the calculation of floor area. To be exempt from floor area, below grade areas must meet the following conditions:
     • (a) The structure must be principally residential or commercial, or accessory thereto; and
     • (b) Below grade areas shall not exceed a maximum depth of ten (10) feet as measured from floor to ceiling and shall include no more than a single story; and
     • (c) Below grade areas cannot exceed the building footprint of the ground floor; and
     • (d) Below grade uses are limited to non-habitable uses such as baths, laundry, mechanical, halls, utility, storage, etc., and shall not include garages or any uses that require natural light or ventilation pursuant to the applicable adopted building code; and
     • (e) No more than one (1) egress may be allowed and is to be provided by a window that does not exceed the minimum requirements of the applicable adopted building code. No new exterior staircases may be allowed to access below grade areas; and
     • (f) No more than one (1) window well may be allowed, but not to exceed the minimum area allowed by the applicable adopted building code, and not to be located on the street facade; and
     • (g) The foundation wall or footing may be exposed no more than two (2) feet above existing grade.; and
     • (h) If any part of the below grade space is exposed above natural or finished grade (such as walk-out basements, walls or courts) the entire below grade area shall be included in the floor area calculation; and
     • (i) All dirt and other material excavated to allow for the below grade area must be removed from the site; and
     • (j) All below grade areas must be approved by the Redstone Historic Preservation Commission, to the extent guidelines are applicable.

(i) Provisions for the RR Zone District

• In the Rural and Remote zone district, the following provisions shall apply:
  1. Maximum footprint per principal structures shall not exceed 1,000 square feet, except without special review approval. In measuring the footprint, all dimensions shall be taken from the outside face of framing or other primary wall members.
  2. Maximum allowed floor area shall not exceed 1,000 square feet, except as may be allowed through special review to retain an existing structure when a new structure is proposed. Up to 600 square feet of a legally created structure existing prior to January 2, 1996, that is retained pursuant to special review, shall be excluded from the maximum allowed floor area for a new, separate structure; floor area in excess of 600 square feet shall be included in floor area calculations. The entire floor area of an historic structure shall be excluded from the maximum allowed floor area.
  3. Decks, porches, etc. shall not exceed a maximum of 500 square feet as measured from the outside face of the material. Structures including, but not limited to decks, porches, slabs, patios and terraces, shall be included in this calculation, and these structures shall be contiguous to the building footprint.
  4. Platforms and tree houses shall not exceed 250 square feet, which is included in the maximum allowed floor area of 1,000 square feet.
  5. Outhouse, storage and mechanical enclosures shall not exceed a total of 160 square feet, which is excluded from maximum allowed floor area of 1,000 square feet.

(j) Floor Area Exemptions for Agricultural Buildings:

• Agricultural Buildings shall be exempt from floor area, subject to the following criteria, on properties utilized for an agricultural operation as defined in Chapter 11 in those zone districts where Agricultural Buildings are listed as an allowed principal agricultural or accessory use in Table 4-1, or in the RS-G, LIR-35 or T zone districts, if approved as a special review use.

(1) Hay Storage Building: To be exempt from floor area, a hay storage building must meet all of the following criteria:

• (a) A hay storage building shall have a maximum of three (3) walls. The fourth side of the building may have a fence or gate to exclude wildlife, but shall not be fully enclosed.
• (b) A hay storage building shall be used only for the protection and storage of hay.
• (c) A hay storage building shall not exceed the following sizes/heights based on acreage.

30’ Maximum to Top of Ridge 20’ Maximum to Top of Ridge

20 to <35 acres 224 square feet 336 square feet

35 to <70 acres 448 square feet 672 square feet

70 to <160 acres 672 square feet 1,008 square feet

160 + acres Unlimited Unlimited

• (d) Additional square footage for a hay storage building may be approved pursuant to Sec. 2-30-20(g)(19) of this Code, Flexibility for Agricultural Support. Otherwise, any additional square footage for a hay storage building shall count as floor area.
• (e) A hay storage building shall not have an excavated, raised or slab foundation.
• (f) A hay storage building shall not contain any mechanical or plumbing equipment. Electrical equipment shall be limited to necessary lighting.

(2) Livestock Run-In or Loafing Shed: To be exempt from floor area, a livestock run-in or loafing shed must meet all of the following criteria;

• (a) A livestock run-in or loafing shed shall have a maximum of three (3) walls. The fourth side may have a fence or gate, but shall not be fully enclosed.
• (b) A livestock run-in or loafing shed shall be used only for livestock protection.
• (c) A livestock run-in or loafing shed shall have a maximum size based on acreage as shown below:
  1. <20 acres: one (1) shed of up to 300 square feet. Staff may approve additional exempt sheds at building permit application, based on a demonstration of need by the property owner.
  2. 20+ acres: unlimited number of sheds at 300 square feet each
• (d) A livestock run-in or loafing shed shall not exceed 12 feet (12’) to the top of the ridge with a minimum 3:12 roof pitch with a shed roof.
• (e) A livestock run-in or loafing shed shall not have an excavated, raised or slab foundation.
• (f) A livestock run-in or loafing shed shall not contain any mechanical, electrical or plumbing equipment.
• (g) A livestock run-in or loafing shed may be movable.

(3) Agricultural Equipment Storage Buildings: To be exempt from floor area, an agricultural equipment storage building must meet all of the following criteria:

• (a) An agricultural equipment storage building shall be used only for storage of equipment utilized for an on-site agricultural operation. The building may contain a workshop/work area utilized for equipment repair and maintenance as a secondary use to the equipment storage.
• (b) An agricultural equipment storage building shall have a maximum size based on acreage as shown below:
  1. 20 to <160 acres: 990 square feet.
  2. 160+ acres: Unlimited
  3. Additional square footage for an agricultural equipment storage building may be approved pursuant to Sec. 2-30-20(g)(19) of this Code, Flexibility for Agricultural Support. Otherwise any additional square footage for an agricultural equipment storage building shall count as floor area.
• (c) An agricultural equipment storage building shall not exceed 16’ to the top of the ridge.
• (d) An agricultural equipment storage building may have an excavated, raised or slab foundation.
• (e) An agricultural equipment storage building shall not contain any plumbing equipment other than a hose bib, but may contain mechanical or electrical equipment.

(4) Barns: To be exempt from floor area, a barn must meet all of the following criteria:

• (a) A barn shall be designed and used to shelter or enclose livestock, feed, or field equipment, or for other purposes in support of an on-site agricultural operation.
• (b) A barn shall not exceed the following height based on acreage as shown below.
  1. < 10 acres: 20’ to the midpoint/ 25’ to the top of the ridge
  2. 10 to <35 acres: 25’ to the midpoint/30’ to the top of the ridge (for one principal barn; additional barns shall not exceed 20’ to midpoint/25’ to top of ridge)
  3. 35+ acres: 28’ to midpoint/33 to top of ridge (for one principal barn; additional barns shall not exceed 20’ to midpoint/25’ to top of ridge)
  4. On flat (less than 3:12 pitch), shed, dome or barrel roofs on any size lot or parcel, no roof point of a barn shall exceed 20’ above the existing or finished grade, whichever is more restrictive.
• (c) A barn shall not exceed the following size based on acreage:
  1. <5 acres: Barns count as floor area.
  2. 5 to < 20 acres: 1,160 square feet for a barn(s) is exempt from floor area
  3. 20 to <30 acres: 1,740 square feet for a barn(s) is exempt from floor area
  4. 30 to <70 acres: 4,060 square feet for a barn(s) is exempt from floor area
  5. 70 to < 160 acres: 58 square feet per acre for a barn(s) is exempt from floor area
  6. 160+ acres: Unlimited square footage for barns is exempt from floor area
  7. Additional square footage for a barn(s) may be approved pursuant to Sec. 2-30-20(g)(19) of this Code, Flexibility for Agricultural Support. Otherwise any additional square footage for a barn(s) shall count as floor area.
• (d) A barn may contain mechanical, electrical and plumbing equipment.
• (e) A barn may contain no more than one (1) toilet room (toilet and lavatory only) not to exceed 20 square feet, unless the toilet room is designed to be accessible, in which case it shall not exceed 43 square feet. Showers and bathing facilities are prohibited, with the exception of a safety shower. A dog wash shall not be permitted within the bathroom.
• (f) A barn may contain office space of no more than 120 square feet related to the on-site agricultural operation. Any additional office space shall count as floor area.
• (g) Human amenities are prohibited within a barn.

(5) Greenhouses: To be exempt from floor area, a greenhouse must meet all of the following criteria:

• (a) Customarily accessory to a principal residential use:
  1. Products grown on the property may only be sold on the premises subject to compliance with the standards in Sec. 4-30-50 for an Agricultural Stand and approval of a Temporary Use Permit pursuant to Sec. 2-30-20.
  2. The greenhouse shall be detached from residential buildings. The greenhouse may be attached to a “U” occupancy building as classified in the International Building Code.
  3. A greenhouse shall be exempt from floor area up to the following sizes based on zone district and acreage:
     • (a) Lot/parcel < 1 acre: 320 square feet.
     • (b) Lot/parcel of 1 to <5 acres: 600 square feet.
     • (c) Lot/parcel of 5 to <10 acres: 1,000 square feet.
     • (d) Lot/parcel of 10 to <35 acres: 1,300 square feet.
     • (e) Lot/parcel of 35 acres or more: 1,600 square feet.
  4. A greenhouse of 200 square feet or less shall not contain any mechanical, electrical or plumbing equipment. A greenhouse in excess of 200 square feet shall not contain any plumbing equipment other than a hose bib, but may contain mechanical or electrical equipment.
  5. No light shall emanate from the interior of the greenhouse such that it is visible from the exterior of the greenhouse from two (2) hours after dusk until two (2) hours before dawn.
  6. Additional square footage for an accessory greenhouse(s) of up to 3,000 square feet may be approved pursuant to Sec. 2-30-20(g)(19) of this Code, Flexibility for Agricultural Support. Otherwise any additional square footage for a greenhouse(s) shall count as floor area or shall be approved through Special Review.
• (b) Not customarily accessory to a principal residential use:
  1. Any greenhouse(s) that contains 3,000 square feet or more requires Special Review approval. If approved, the greenhouse(s) shall be exempt from floor area.
  2. The greenhouse(s) may contain mechanical, electrical and plumbing equipment.
  3. The greenhouse(s) may contain no more than one (1) accessible toilet room (toilet and lavatory only) not to exceed 43 square feet. Showers and bathing facilities are prohibited, with the excepton of a safety shower.
  4. The greenhouse(s) may contain one office space of no more than 120 square feet related to the on-site agricultural operation.
• (c) Any greenhouse that is no longer is a useable condition fo rhte intended purpose shall be removed or demolished.

(6) Agricultural Building Review Committee: The Agricultural Building Review Committee shall review land use and building permit applications for exempt floor area for agricultural buildings and make a recommendation to Community Development Department as to whether the agricultural building is designed to support an agricultural operation and is functional for agricultural uses. The Community Development Department shall have the discretion to determine which applications for agricultural buildings should be referred to the Committee for review; an Applicant may also request a Committee Review.

(7) Agricultural Buildings Constructed Prior to October 18, 2011: Agricultural buildings legally constructed prior to October 18, 2011 shall count towards the floor area exemptions for agricultural buildings provided herein.

• (a) If the total size of the agricultural building(s) on the lot or parcel is less than the maximum size permitted in this Sec. 5-20-70(j), then the existing agricultural building(s) can be replaced and can be expanded, up to a total of the size permitted in this Sec. 5-20-70(j) for each type of agricultural building.
• (b) If the total size of the agricultural building(s) on the lot or parcel is more than the maximum size permitted in this Sec. 5-20-70(j), then the existing agricultural building(s) may be replaced, but may not be expanded without obtaining additional exempt floor area pursuant to Sec. 2-30-20(g)(19), a GMQS allotment or transferable development rights.

(8) Occupancy Covenant and Agreement: An Occupancy Covenant and Agreement shall be recorded against a property that takes advantage of a floor area exemption for an agricultural building, prior to issuance of a building permit for a new or expanded agricultural building. The Occupancy Covenant and Agreement shall specify that the exempt floor area may only be used in association with the raising, producing, or keeping of plants or livestock, or cultivation and management of other crops or farm products, and that any area not consistent with those uses would count as floor area. The Occupancy Covenant and Agreement shall also allow the county to inspect the agricultural building at any time for compliance with the specified use limitations, subject to the provision of reasonable notice to the property owner. The form of the Occupancy Covenant and Agreement shall be approved by the County Attorney.

(9) Common Agricultural Buildings: Within a Board approved subdivision or PUD in the AR-10, RS-20, RS-30, RS-35, LIR-35 or RS-160 zone districts, where agricultural buildings are limited to a common lot/parcel and prohibited on individual lots/parcels as part of the subdivision or PUD approval, the total acreage of all of the lots within the subdivision or PUD may be utilized to determine the common agricultural building floor area exemption. This provision may be utilized for a common parcel within a development of parcels in excess of thirty-five (35) acres not within a Board approved subdivision or PUD pursuant to the procedures of Sec. 2-30-20 and the criteria of Sec. 2-30-30(h)(2).

(10) Review Provision: This floor area exemption for agricultural buildings (Sec. 5-20-70.i) as a whole shall be reviewed by the Board of County Commissioners after four years from October 18, 2011. The purpose of the review will be to review how the exemptions have been used, and whether the exemptions shall be retained, modified or repealed.