International Residential Code
The 2009 International Residential Code, incorporated by reference into the Washington State Building Code (WAC 51-51). Covers the design and construction of one- and two-family dwellings and townhouses.
International Residential Code (2009)
Washington adopted the 2009 IRC as WAC 51-51, effective July 1, 2010, with state amendments (Washington does not adopt the IRC energy chapter, relying instead on its own State Energy Code). The full text below is reproduced from the 2009 edition as incorporated into law, sourced from public.resource.org, and covers building planning, structural, mechanical, and plumbing provisions for homes.
- Appliance Installation
This chapter outlines the general installation requirements for various appliances and fixed heating equipment within residential buildings.
- Boilers and Water Heaters
This chapter establishes the installation and safety requirements for boilers, water heaters, and pool heaters, including controls, expansion tanks, and manufacturer instructions.
- Branch Circuit and Feeder Requirements
This chapter outlines the minimum requirements for branch circuits and feeders serving less than 100 percent of the total dwelling unit load, including their ratings, allowable loads, and overcurrent protection.
- Building Planning
This chapter establishes fundamental building planning and construction requirements for residential dwellings, covering design criteria, fire resistance, minimum dimensions, essential facilities, and protection against various hazards.
- Chimneys and Fireplaces
This chapter establishes the requirements for the construction and installation of masonry and factory-built fireplaces, masonry heaters, and their associated chimneys, including exterior air supply provisions.
- Chimneys and Vents
This chapter outlines requirements for venting fuel-burning appliances to the outdoors, including specifications for vent components, connectors, and chimney construction.
- Class 2 Remote-control, Signaling and Power-limited Circuits
This chapter outlines requirements for power supplies and wiring methods for Class 2 remote-control, signaling, and power-limited circuits not integrated into devices.
- Combustion Air
This chapter establishes requirements for providing combustion air to solid-fuel-burning and oil-fired appliances, referencing manufacturer instructions and NFPA 31.
- Definitions
This chapter establishes the definitions for words and terms used throughout the code, ensuring consistent interpretation of its provisions.
- Devices and Luminaires
This chapter establishes requirements for the rating, application, and installation of electrical switches, receptacles, fixtures, luminaires, and track lighting.
- Duct Systems
This chapter outlines requirements for the design, fabrication, and installation of duct systems and return air provisions for heating, cooling, and ventilation equipment in dwellings.
- Electrical Definitions
This chapter provides definitions for terms that are specifically used within the electrical requirements outlined in Chapters 34 through 43 of this code.
- Energy Efficiency
This chapter establishes regulations for the energy efficiency in the design and construction of buildings covered by this code.
- Exhaust Systems
This chapter outlines requirements for mechanical exhaust systems, including general outdoor discharge, specific rules for clothes dryers, range hoods, and overhead exhaust hoods.
- Floors
This chapter establishes the design and construction requirements for floors in all buildings, including those in attic spaces used for mechanical or plumbing equipment.
- Foundations
This chapter outlines the design and construction requirements for foundations and foundation spaces in all buildings, including specific provisions for materials, footings, walls, drainage, waterproofing, columns, and under-floor ventilation.
- Fuel Gas
This chapter establishes requirements for the design, installation, and maintenance of fuel gas piping systems, appliances, venting, and combustion air in one- and two-family dwellings.
- General Mechanical System Requirements
This chapter establishes general requirements for the installation of mechanical systems and appliances, addressing approval, labeling, fuel type, access, clearances, and installation practices not covered elsewhere.
- General Plumbing Requirements
This chapter outlines general plumbing requirements, covering water supply, sewage disposal, structural protection during installation, trenching, pipe support, waterproofing, workmanship, and material identification.
- General Requirements
Chapters 34 through 43 outline general electrical system and equipment requirements for one- and two-family dwellings, covering wiring, structural protection, clearances, and conductor identification.
- Heating and Cooling Equipment
This chapter establishes general installation requirements and specific standards for various heating and cooling equipment and appliances, including furnaces, heat pumps, and refrigeration systems.
- Hvdronic Piping
This chapter establishes installation and material requirements for hydronic piping systems, including baseboard convectors, floor heating, low-temperature piping, and ground source heat pump loops.
- Mechanical Administration
Chapters 12 through 24 regulate the design, installation, maintenance, alteration, and inspection of permanently installed mechanical systems used to control environmental conditions within buildings.
- Plumbing Administration
This chapter establishes the general administrative requirements and inspection criteria for plumbing systems as mandated by this code.
- Plumbing Fixtures
This chapter establishes requirements for the quality, materials, installation, and specific features of plumbing fixtures, faucets, and their accessories in residential buildings.
- Power and Lighting Distribution
This chapter establishes requirements for the installation of receptacle and lighting outlets, ground-fault and arc-fault protection, and general wiring practices for power and lighting distribution.
- Referenced Standards
- Roof Assemblies
This chapter governs the design, materials, construction, and quality of roof assemblies, including classifications, weather protection, insulation, and reroofing requirements.
- Roof-ceiling Construction
This chapter establishes requirements for the design and construction of roof-ceiling systems, encompassing framing, sheathing, finishes, ventilation, and attic access.
- Sanitary Drainage
This chapter establishes requirements for the materials, design, construction, and installation of sanitary drainage systems, including all piping for conveying wastes from plumbing fixtures.
- Scope and Administration
This chapter establishes the administrative framework for the Residential Code, covering its scope, enforcement, permits, inspections, and appeals processes for one- and two-family dwellings.
- Services
Chapter 36 governs the installation requirements for service conductors and equipment, including their size, rating, grounding, bonding, and clearances.
- Solar Systems
This chapter governs the design, construction, installation, alteration, and repair of solar energy systems for space heating/cooling, hot water heating, and swimming pools.
- Special Fuel-burning Equipment
This chapter governs the installation and clearance requirements for various special fuel-burning equipment, including ranges, sauna heaters, fuel cell power plants, and gaseous hydrogen systems.
- Special Piping and Storage Systems
This chapter outlines material, installation, and component requirements for oil tanks, piping, pumps, and valves within special piping and storage systems.
- Storm Drainage
This chapter establishes requirements for the materials, design, construction, and installation of storm drainage systems for buildings.
- Swimming Pools
This chapter governs the construction and installation of electrical wiring and equipment for permanently installed or storable swimming pools, spas, hot tubs, decorative pools, fountains, and hydromassage bathtubs.
- Traps
This chapter establishes design requirements and approved materials for fixture traps, ensuring they are self-cleaning and have smooth internal waterways.
- Vents
This chapter governs the selection and installation of piping, tubing, and fittings for plumbing vent systems, including minimum diameters, sizing, length, and various types of vents.
- Wall Construction
This chapter outlines the design and construction requirements for various wall types and partitions, including wood, steel, masonry, concrete, and structural insulated panels, along with exterior windows and doors.
- Wall Covering
This chapter establishes the design and construction requirements for both interior and exterior wall coverings for all buildings, ensuring proper application and weather resistance.
- Water Heaters
This chapter outlines requirements for domestic water heaters, including installation, protection of potable water, and safety devices like relief valves.
- Water Supply and Distribution
This chapter establishes requirements for potable water supply, distribution system design, protection against contamination, and specifications for materials, supports, and fire sprinkler systems in dwelling units.
- Wiring Methods
This chapter establishes the wiring methods for services, feeders, and branch circuits used for electrical power and distribution in buildings.