Square Footage Standards - Residential (ALL)

Question 1

What is the minimum square footage for habitable rooms?

Answer 1

70 SF (net) minimum, except Kitchens

Refer to IRC 2018 304.1 & IBC 2018 1207.1

Question 2

What is the minimum horizontal dimension allowed in a room?

Answer 2

7’-0”

This means the minimum size room is 7x10 (IRC 2018 304.2)

Question 3

In some residential settings, what is the minimum square footage required for one room?

Answer 3

120 SF (net)

Refer to IBC 2018 1207.3

Question 4

What is the required clear passageway for kitchens?

Answer 4

36”

Between appliances and wall or counters (IBC 1207.1)

Question 5

What is the minimum ceiling height in non-habitable basements, bathrooms, closets, and laundry rooms?

Answer 5

6’-8”

Refer to IRC 2018 305.1.1

Question 6

What is the minimum ceiling height in all rooms including habitable basements?

Answer 6

7’-0”

Refer to IRC 2018 305.1

Question 7

What is the minimum height allowed in habitable basements to the bottom of a beam, girder, duct or obstruction?

Answer 7

6’-4”

Refer to IRC 2018 305.1

Question 8

What ceiling height is not considered habitable?

Answer 8

Lower than 5 feet and not less than 50% of the sf of the area

Refer to IRC 305.1 (1) & IBC 1207.2

Question 9

What is the aggregate glazing area requirement for habitable rooms?

Answer 9

Not less than 8% of the floor area

For a 10x10 room, this requires an openable area of 4 SF

Question 10

What is the minimum openable area to the outdoors for natural ventilation?

Answer 10

4% of the floor area being ventilated

For a 10x10 room, this requires an openable area of 4 SF

Question 11

True or False

Exceptions allow the use of artificial light and mechanical ventilation in bathrooms.

Answer 11

True

This is applicable regardless of natural ventilation requirements.