§ Chapter 3 IRC 2021
Building Planning
22 entries from Chapter 3 of IRC 2021, organized by section number. Each entry covers what the code requires, why it exists, what inspectors look for, and common mistakes.
§ 01 Sections
All 22 entries.
Sorted by section number. Click any row for the full entry — answer, requirements, edition diff, related sections.
Section
Title
Question
R302.1
Fire Separation Distance Controls Walls and Openings Near Property Lines
R302.1
How close can I build a house, addition, deck, or shed to the property line before I need fire-rated walls or protected openings?
How close can I build a house, addition, deck, or shed to the property line before I need fire-rated walls or protected openings?
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R302.5.1
Garage-to-House Doors Must Meet IRC Opening Protection Rules
R302.5.1
Does the door from the garage into the house have to be fire-rated, solid core, and self-closing?
Does the door from the garage into the house have to be fire-rated, solid core, and self-closing?
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R302.6
Garage and House Separation Requires Specific Drywall Protection
R302.6
Does the wall between my garage and house need to be fire-rated, and what drywall is required?
Does the wall between my garage and house need to be fire-rated, and what drywall is required?
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R303.1
Habitable Rooms Need Required Light and Ventilation
R303.1
Do bedrooms and living rooms need windows, or can mechanical ventilation satisfy the code?
Do bedrooms and living rooms need windows, or can mechanical ventilation satisfy the code?
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R303.3
Bathrooms Need Natural Ventilation or Mechanical Exhaust
R303.3
Does a bathroom need an operable window if it has an exhaust fan?
Does a bathroom need an operable window if it has an exhaust fan?
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R304.1
Habitable Rooms Must Meet Minimum Floor Area Rules
R304.1
What is the minimum size for a bedroom or habitable room?
What is the minimum size for a bedroom or habitable room?
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R305.1
Finished Basements Must Meet Minimum Ceiling Height
R305.1
What is the minimum ceiling height for a basement bedroom or finished basement?
What is the minimum ceiling height for a basement bedroom or finished basement?
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R305.1
Sloped Ceilings Need Enough Compliant Headroom
R305.1
How much low or sloped ceiling area is allowed in a finished attic, loft, or bonus room?
How much low or sloped ceiling area is allowed in a finished attic, loft, or bonus room?
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R306.1
Dwelling Units Need Minimum Plumbing Fixtures
R306.1
What plumbing fixtures are required for a dwelling unit?
What plumbing fixtures are required for a dwelling unit?
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R308.4
Safety Glazing Is Required in Hazardous Locations
R308.4
When does glass near a door, stair, shower, tub, or floor have to be tempered or safety glass?
When does glass near a door, stair, shower, tub, or floor have to be tempered or safety glass?
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R310.1
Bedrooms Need Emergency Escape and Rescue Openings
R310.1
Does every bedroom need an egress window or exterior door?
Does every bedroom need an egress window or exterior door?
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R310.2.1, R310.2.2
Egress Windows Must Meet Clear Opening and Sill Height Rules
R310.2.1, R310.2.2
What are the minimum egress window size, clear opening, sill height, and dimensions?
What are the minimum egress window size, clear opening, sill height, and dimensions?
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R311.2
A Dwelling Needs a Required Exterior Egress Door
R311.2
How many exterior doors are required from a house, and does a patio door count?
How many exterior doors are required from a house, and does a patio door count?
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R311.3
Exterior Doors Usually Need Landings at Each Side
R311.3
Is a landing required at an exterior door, garage door, or door at the top of stairs?
Is a landing required at an exterior door, garage door, or door at the top of stairs?
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R311.7
Stairways Need Consistent Risers, Proper Treads, Landings, Lighting, and Handrails
R311.7
What stairway details does the IRC require beyond basic guard height?
What stairway details does the IRC require beyond basic guard height?
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R312.1.1
Guards Are Required Where Walking Surfaces Are More Than 30 Inches High
R312.1.1
When is a guardrail required on a deck, porch, balcony, or stair landing?
When is a guardrail required on a deck, porch, balcony, or stair landing?
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R312.1.2, R312.1.3
Guards Need Minimum Height and Limited Opening Size
R312.1.2, R312.1.3
How high do guards need to be, and what is the maximum baluster spacing?
How high do guards need to be, and what is the maximum baluster spacing?
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R314.3
Smoke Alarms Are Required in Bedrooms, Hallways, and Each Story
R314.3
Where are smoke alarms required in a house, bedroom, hallway, basement, or each story?
Where are smoke alarms required in a house, bedroom, hallway, basement, or each story?
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R314.4, R314.6
Smoke Alarms Often Need Power and Interconnection During Remodels
R314.4, R314.6
Do smoke alarms have to be hardwired and interconnected when remodeling or finishing a basement?
Do smoke alarms have to be hardwired and interconnected when remodeling or finishing a basement?
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R315.2
Carbon Monoxide Alarms Are Required With Fuel-Burning Appliances or Attached Garages
R315.2
When are carbon monoxide alarms required because of an attached garage, fireplace, furnace, water heater, or gas appliance?
When are carbon monoxide alarms required because of an attached garage, fireplace, furnace, water heater, or gas appliance?
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R320.1
Townhouse Accessibility Depends on the Applicable Code Path
R320.1
Do new single-family homes or townhouses have to be accessible or adaptable?
Do new single-family homes or townhouses have to be accessible or adaptable?
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R326.1
Residential Pool Barriers Must Limit Unsupervised Access
R326.1
What fence or barrier is required around a residential swimming pool?
What fence or barrier is required around a residential swimming pool?
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