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Boulder, CO Building Safety: Plumbing Permits (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Governing section
City Code § 10-10-2(a)-(b)
Code adopted
2024 International Plumbing Code with Appendix E
Permit administration
Follows Building Code Chapter 1 permitting process
Water closet flow limit
1.28 gallons per flushing cycle
Test pressure
100 psi for non-plastic water supply piping

Summary

Boulder adopts the 2024 International Plumbing Code, with Appendix E, as the City of Boulder Plumbing Code under City Code Section 10-10-2(a), and administers plumbing permits through the same Chapter 1 permitting rules used for the building code. Local amendments raise water test pressure, delete the graywater and nonpotable water chapters, and set flow-rate limits on fixtures.

(a)The 2024 edition of the International Plumbing Code, published by the International Code Council, including Appendix E, "Sizing of Water Piping System," is hereby adopted by reference as the City of Boulder Plumbing Code or plumbing code, and has the same force and effect as though fully set forth in this chapter, except as specifically amended by the provisions of this chapter.(b)Except for Sections 101, 102, and 107, Chapter 1 is repealed. This code shall be administered in accordance with Chapter 1, "Administration," of the International Building Code as adopted, with amendments, by Section 10-5-2, "Adoption of International Building Code With Modifications," B.R.C. 1981.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 167 Update 3).

Full Breakdown

City Code Section 10-10-2(a) adopts the 2024 edition of the International Plumbing Code, including Appendix E, "Sizing of Water Piping System," by reference as the City of Boulder Plumbing Code, giving it the same force and effect as if set out in full in the chapter, except where the chapter's amendments apply. Subsection (b) repeals most of the code's own Chapter 1, keeping only Sections 101, 102, and 107, and instead administers plumbing permits under Chapter 1, "Administration," of the City of Boulder Building Code adopted at Section 10-5-2, meaning a plumbing permit follows the same application, plan review, and inspection process as a building permit.

3, and repealing the code's own disinfection-of-potable-water-system section, Section 610, in favor of separate city standards. 0 gallon-per-minute shower head limit. The chapter also deletes Chapter 13, "Nonpotable Water Systems," and Chapter 14, "Subsurface Graywater Soil Absorption Systems," from the adopted plumbing code in their entirety, channeling graywater questions instead to the separate prohibition in Section 10-10-3.

Violations & Fines

Because plumbing permits are administered under the Building Code's Chapter 1, plumbing violations follow that code's Section 113.1 civil penalty schedule of $100, $300, then $1,000 for repeat violations within twelve months, plus stop-work authority and criminal prosecution under Section 5-2-4. Unpermitted plumbing work can also delay a certificate of occupancy until the code official signs off on inspection.

Frequently Asked Questions

What plumbing code does Boulder use for permits?
City Code Section 10-10-2(a) adopts the 2024 International Plumbing Code, including Appendix E on sizing water piping systems, by reference as the City of Boulder Plumbing Code, with local amendments to test pressure, fixture flow rates, and administration.
How do I get a plumbing permit in Boulder?
Section 10-10-2(b) repeals most of the Plumbing Code's own administrative chapter and instead applies Chapter 1, "Administration," of the City of Boulder Building Code, adopted at Section 10-5-2, so plumbing permits go through the same application and inspection process as building permits.
Are there local water-pressure or fixture requirements?
Yes. Section 312.5 raises the water supply system test pressure from 50 psi to 100 psi for non-plastic piping, and Table 404.4 caps fixture flow rates, including 1.28 gallons per flush for water closets and 2.0 gallons per minute for shower heads.

Sources & Official References

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