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Building Codes

Austin Plumbing Codes 2025: What Homeowners Need to Know

Stay compliant with the latest Austin plumbing regulations. Understanding code requirements can save you time, money, and headaches during renovations.

Published: January 8, 2025 • 12 min read

Austin follows the International Plumbing Code (IPC) with local amendments. Whether you're planning a bathroom remodel, adding a new fixture, or dealing with repairs, understanding these codes helps ensure your project meets safety standards and passes inspection.

Austin Plumbing Code Overview

Code Foundation

  • Based on 2021 International Plumbing Code
  • Austin-specific amendments and modifications
  • Regular updates and revisions
  • Coordinated with building and electrical codes

Key Objectives

  • Protect public health and safety
  • Ensure proper sanitation
  • Prevent contamination of water supply
  • Standardize installation practices

When You Need a Permit

Permit Required

These projects always need permits in Austin

  • • New plumbing installations
  • • Moving existing plumbing fixtures
  • • Installing new water heaters
  • • Adding new bathroom or kitchen
  • • Sewer line repairs or replacements
  • • Water service line work
  • • Gas line installations
  • • Backflow prevention device installation
  • • Septic system work
  • • Commercial plumbing projects
  • • Whole-house repiping
  • • Swimming pool plumbing

No Permit Needed

Minor repairs and maintenance typically don't require permits

  • • Replacing faucets or fixtures (same location)
  • • Toilet replacement (same location)
  • • Clearing drain clogs
  • • Replacing water heater elements
  • • Minor leak repairs
  • • Replacing supply lines to fixtures
  • • Installing water filters
  • • Garbage disposal replacement
  • • Routine maintenance
  • • Emergency repairs

Key Code Requirements

Water Supply Systems

Pipe Materials:

  • Approved materials: Copper, CPVC, PEX, PVC (cold water only)
  • Prohibited: Lead pipes, galvanized steel for new installations
  • PEX requirements: Must be certified to ASTM standards

Installation Standards:

  • Minimum 3/4" service line for single-family homes
  • Proper pipe support every 6-8 feet
  • Insulation required in unconditioned spaces
  • Backflow prevention where required

Drainage Systems

Pipe Sizing:

  • Toilet drains: Minimum 3" diameter
  • Shower/tub drains: Minimum 2" diameter
  • Sink drains: Minimum 1.5" diameter
  • Main building drain: Minimum 4" diameter

Slope Requirements:

  • 4" pipes: 1/8" per foot minimum slope
  • 3" pipes: 1/4" per foot minimum slope
  • 2" and smaller: 1/4" per foot minimum slope

Venting Requirements

General Rules:

  • Every fixture must be properly vented
  • Vent pipes must extend through roof
  • Minimum vent size: 1.5" diameter
  • Vents must be at least 6" above roof line

Distance Limitations:

  • Toilets: Maximum 6 feet from vent
  • Sinks: Maximum 3.5 feet from vent
  • Floor drains: Maximum 15 feet from vent

Water Heater Code Requirements

Installation Requirements

  • Minimum 18" clearance on all sides for gas units
  • Proper venting for gas water heaters
  • Temperature and pressure relief valve required
  • Drain pan required in certain locations
  • Seismic strapping in earthquake zones
  • Proper electrical connections for electric units

Safety Features

  • Gas shutoff valve within 6 feet
  • Electrical disconnect switch required
  • Carbon monoxide detectors (gas units)
  • Proper combustion air supply
  • Expansion tank for closed systems
  • GFCI protection where required

Bathroom Code Requirements

Fixture Spacing

Minimum Clearances:

  • Toilet: 15" from centerline to wall
  • Toilet: 21" clear space in front
  • Sink: 4" from centerline to wall
  • Shower: 24" x 24" minimum interior

Accessibility (when required):

  • 36" wide doorways
  • 60" turning radius clear space
  • Grab bar reinforcement
  • Accessible fixture heights

Ventilation Requirements

Mechanical Ventilation:

  • 50 CFM minimum for bathrooms up to 100 sq ft
  • Additional 1 CFM per sq ft over 100 sq ft
  • Must exhaust to exterior, not attic
  • Timer or humidity controls recommended

Natural Ventilation Alternative:

  • Operable window of at least 3 sq ft
  • Window area must be 10% of floor area
  • Not recommended for interior bathrooms

Inspection Process

Required Inspections

Rough-In Inspection:
  • Before covering pipes with drywall
  • Verifies pipe sizing and routing
  • Checks venting system
  • Tests water pressure
Final Inspection:
  • After all fixtures are installed
  • Tests all connections
  • Verifies proper operation
  • Checks code compliance

Scheduling Tips

  • Schedule inspections at least 24 hours in advance
  • Be present or have contractor available during inspection
  • Have permits and plans readily available
  • Address any violations promptly
  • Request re-inspection after corrections

Common Code Violations

Installation Issues

  • • Improper pipe support or hangers
  • • Incorrect pipe sizing
  • • Missing or inadequate venting
  • • Improper drain slopes
  • • Cross-connections between potable and non-potable water
  • • Missing shutoff valves

Safety Violations

  • • Missing GFCI protection
  • • Improper water heater installation
  • • Inadequate fixture clearances
  • • Missing backflow prevention
  • • Improper gas line connections
  • • Insufficient ventilation

Working with Licensed Professionals

Why Use Licensed Plumbers:

  • Thorough knowledge of current codes
  • Experience with permit process
  • Proper tools and materials
  • Insurance and warranty protection
  • Relationship with inspectors

Questions to Ask:

  • Are you licensed in Austin?
  • Will you pull the necessary permits?
  • Do you guarantee code compliance?
  • What warranty do you provide?
  • Are you insured and bonded?

Need Code-Compliant Plumbing Work?

Don't risk code violations or failed inspections. Our licensed plumbers know Austin codes inside and out and handle all permit requirements for you.

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