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Larimer County, Colorado Building Codes

Updated : 04/22/2024

Overview

Larimer County, CO adopts the following codes:

  • The International Building Code, 2021 edition. Larimer County, CO County Code § 10-31 (adopted) with amendments at § 10-32.
  • The International Residential Code, 2021 edition. Larimer County, CO County Code § 10-1 (adopted) with amendments at § 10-2.
  • The International Existing Building Code, 2021 edition. Larimer County, CO County Code § 10-121 (adopted) with amendments at § 10-122.
  • The International Property Maintenance Code, 2021 edition. Larimer County, CO County Code § 10-123 (adopted) with amendments at § 10-124.
Helpful resources for Larimer County, Colorado include the following.

Residential Building Code

Colorado has yet to adopt a statewide residential code. Local laws will control.See PLRB, Colorado Building Codes for more information on state level codes.

Larimer County adopted the 2021 IRC, locally. Note that adoptions usually come with amendments. So, it is important to review those amendments in addition to the unamended model code.

You can find a copy of the model code here.

You can find information about amendments to the model code here.

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2021 IRC(Larimer County, CO Sec. 10-1. - International Residential Code (IRC)—Adopted.)

...The 2021 International Residential Code with amendments thereto which are adopted in section 10-2 are hereby adopted and shall be part of the Larimer County Building Code effective March 1, 2022. (Res. No. 01292019R001, Exh. A, 1-29-2019; Res. No. 01-25-2022(1), § 6(Exh. A), 1-25-2022) Editor's note—...

Drip Edge

Drip Edge: yes

Ice Barrier

Are ice barriers required for Larimer County ? Yes
Citation: Larimer County, CO County Code § 10-2.
Municipal Code https://library.municode.com/co/larimer_county/codes/code_of_ordinances?nodeId=PTIGECO_CH10BUBURE_ARTIBUSTOMIDW_S10-2AM
Comments:

TABLE 301.2 (1) CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA

Ground Snow Load o
(P g )
Wind Design Seismic Design Cate-gory f Subject to
Damage from
Winter Design Temperature e
Speed d
(mph)
Topographic effects k Special Wind Region l Wind-borne debris zone m Weathering a Frost Line Depth b Termite c
35psf ≤5,000'
45psf ≤6,000'
50psf ≤6,500'
60psf ≤7,000'
70psf ≤8,000'
100psf ≤9,000'
140psf ≤10,000'

Engineered design required over 10,000'
115-225 mph

Ultimate Design Wind Speed
V ult
YES YES NO B Severe 30 inches Slight to Moderate +4 o F

 

Ice Barrier Underlayment Required h Flood Hazards g Air Freezing Index i Mean Annual Temperature j
YES  a) 1973
 b) Feb. 6, 2013
 c) Panels 08069C0025
through 08069C1420
906 in the Class C roofing area
(Front Range)
920 in the Class B roofing area
(foothills & mountains)
48.4 o F

 

For SI: 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447m/s.

Elevation Latitude Winter Heating Outdoor Design Dry-bulb Summer Cooling Outdoor Design Dry-bulb Altitude Correction Factor Design
Temp.
Heating Wet-bulb
Design
Temp.
Cooling Dry-bulb
Heating Temp. Difference
4,935 40 o North 4 o F 91 o F .85 72 o F 75 o F 68 o F
Cooling
Temp
Difference
Wind
Velocity Heating
Wind
Velocity Cooling
Coincident
Wet
Bulb
Daily
Range
Winter Humidity Summer
Humidity
 
16 o F 15 mph 7.5 mph 62 o F High (H) 50% 50%  

 

Comments

Larimer County, CO adopts the International Residential Code, 2021 edition, including Appendix Chapters A, B, C, E, F, H, and J. Larimer County, CO County Code § 10-1 (adopted) with amendments at § 10-2.

Existing Buildings

Existing buildings, meaning buildings that were built in accordance to code at the time of construction, typically merit extra consideration in a current updated code.

Larimer County, CO adopts the International Property Maintenance Code, 2021 edition. Larimer County, CO County Code § 10-123 (adopted) with amendments at § 10-124.

Also, refer to Appendix Chapter J of the adopted 2018 IRC.

Commercial Building Code

Larimer County adopted the 2021 IBC, locally. Note that adoptions usually come with amendments. So, it is important to review those amendments in addition to the unamended model code.

You can find a copy of the code here.You can find information about amendments to the model code here.

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2021 IBC(Larimer County, CO Sec. 10-31. - International Building Code (IBC)—Adopted.)

...The 2021 International Building Code with amendments thereto which are adopted in section 10-32 are hereby adopted and shall be part of the Larimer County Building Code effective March 1, 2022. (Res. No. 01292019R001, Exh. B, 1-29-2019; Res. No. 01-25-2022(1), § 6(Exh. B), 1-25-2022) Editor's note—...

Comments

Larimer County, CO adopts the International Building Code, 2021 edition, including Appendix Chapters C, E, and I. Larimer County, CO County Code § 10-31 (adopted) with amendments at § 10-32.

Existing Buildings

Larimer County, CO adopts the following codes:

  • The International Existing Building Code, 2021 edition. Larimer County, CO County Code § 10-121 (adopted) with amendments at § 10-122.
  • The International Property Maintenance Code, 2021 edition. Larimer County, CO County Code § 10-123 (adopted) with amendments at § 10-124.

Other Building Codes

Larimer County, CO also adopts the following codes:

  • The International Plumbing Code, 2021 edition. Larimer County, CO County Code § 10-61 (adopted) with amendments at § 10-62.
  • The International Fuel Gas Code, 2021 edition. Larimer County, CO County Code § 10-91 (adopted) with amendments at § 10-92.
  • The International Mechanical Code, 2021 edition. Larimer County, CO County Code § 10-111 (adopted) with amendments at § 10-112.
  • The International Energy Conservation Code, 2021 edition. Larimer County, CO County Code § 10-151 (adopted) with amendments at § 10-152.
  • The Uniform Fire Code, 1997 edition, including appendices I-A, I-C, II-A, II-B, II-C, II-D, II-E, III-A, III-B, III-C, III-D, IV-A, V-A, VI-A, VI-B, and VI-C. Larimer County, CO County Code § 24-46 (adopted) with amendments at § 26-47.