Meeting standard dimensional specifications after you build is costly and time consuming. Doing things wrong means ripping out walls, and moving electrical outlets, buying more sheetrock, lumber, and labor. So, there is value in knowing the standard dimensional specifications, and planning with these specifications in mind.

So, what are these specifications? Well, here is a list of some of the standard dimensional specifications, but you will want to check with the building department for a full and complete list for your city or county.

General

• Floor to ceiling: 7'6" minimum with no beams projecting down more than 6".
• Smoke detectors must be located in each sleeping area or in hallway located centrally to the sleeping areas.

Bedroom

• No dimensions less than 7' in any direction.
• Two means of escape in case of fire, one door, one window.
• Closet in all bedrooms
• Easy access to a bath
• Space on a wall for a queen size bed
• At least one window
• Room for a 6' dresser
• Should not have to go through a bedroom to get to any other room
• Bed to closet: 36" minimum
• Bed to dresser: 36" minimum
• There are other minimal space requirements between beds etc.

Closet

• Depth: 24"
• Pole height: 5' to 6'
• Pole depth: 1" from closet rear wall
• Unsupported clothes rack: 4' maximum
• Shelving depth: 6"
• Shelving spacing: 8" vertical clearance

Hallways

• Minimum width: 36"
• Minimize overall hallway length

Dining Room

• Eight-person dining room: 10' x 12' minimum
• Direct access to kitchen
• Should not have to walk through dining room to access any other room

Kitchen

• A clear walkway at least 32" wide must be provided at all entrances to the kitchen
• No entry or appliance door may interfere with work center appliances and/or counter space
• Work aisles must be at least 42" wide, and passageways must be at least 36" wide for a one-cook kitchen
• In kitchens 150 sq ft or less, at least 144" of wall cabinet frontage, with cabinets at least 12" deep and a minimum of 30" high must be installed over countertops.
• In kitchens over 150 sq ft, 186" of wall cabinets must be included. Diagonal or precut wall cabinets count as a total of 24".
• There are several other specifications for kitchens, too numerous to include, so check with the county because these get complex.

Cabinets

• Base cabinet depth: 24"
• Floor-to-countertop: 36"
• Countertop to bottom of range vent: 24"
• Countertop to bottom of unprotected (wood) wall cabinets: 30"
• Minimum of 40 sq ft of cabinet shelf space per household member

Refrigerator

• At least 15" from inside countertop corner

Range

• At least 9" from an inside countertop corner
• Horizontal clearance from a wall cabinet: 12"

Bathroom

• A clear walkway of at least 32" must be provided at all entrances to the bathroom
• No doors may interfere with fixtures
• Mechanical ventilation system must be included in the plan
• Ground fault circuit interrupters specified on all receptacles. No switches within 60" of any water source. All light fixtures above tub/shower units are moisture-proof special-purpose fixtures.
• If floor space exists between two fixtures, at least 6" of space should be provided for cleaning
• At least 21" of clear walkway space exists in front of the lavatory and toilet
• A minimum clearance from the center of the toilet to any obstruction, fixture, or equipment on either side of the toilet is 15"
• Toilet paper holder must be installed within reach of person seated on toilet.
• No more than one step leads to the tub
• Bathtub faucets are accessible from outside the tub
• At least one grab bar is installed to facilitate bathtub or shower entry
• Minimum usable shower interior dimension is 32"x 32"
• Bench or footrest is installed within shower enclosure
• Shower door swings into bathroom
• There are other bathrooms specifications, and they vary depending on your city and county, so check before you start building.