Know the Rules for Finished Basements

Finishing your basement? Be sure that your remodeling work is in compliance with building codes in your area.

By Maureen Blaney Flietner and Bob Vila | Updated Oct 5, 2020 6:48 PM

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Finished Basement Code Requirements

Photo: Flickr

Converting your basement is like finding new space, fully equipped with plumbing and heat. Before you begin your remodeling, however, you’ll need to check local codes for safety exits or egress.

Know Your Code

Basement living space requires emergency escape and rescue openings. Your first step is to check local building codes. Your code authority may have authored its own rules or it may be among the more than 90 percent of communities in the United States that adopt the standards of the International Code Council (ICC). The council is a nonprofit organization that publishes new editions of the codes every three years and, in interim years, produces a supplement. The ICC’s 2006 International Residential Code for One- and Two-Story Dwellings has new language stating that basements that contain one or more sleeping rooms are required to have emergency egress and rescue openings in each sleeping room. Emergency exit and rescue openings are not required in adjoining areas of the basement, according to the code.

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Marc Nard, ICC technical expert, further explains which spaces require emergency egress or exit openings, saying emergency exits are required in basement sleeping rooms or habitable space — defined as spaces used for living, sleeping, eating, or cooking. While that does not include spaces like bathrooms, toilet rooms, closets, halls, storage spaces, or utility spaces, it does include offices, recreation rooms, bedrooms, and home theaters. 

There are some fine points. For example, a basement that has no bedroom but has an office would need an emergency exit for the office. But, says Nard, “Say you have a basement bedroom and an office which is not in the bedroom. How many emergency egress and rescue openings do you need? Answer: One, but it has to be in the sleeping room.”

Egress Requirements

Whether it is an egress window or an egress door, it has to open to the outside and open easily without the use of keys or tools. It must also follow code requirements for the height and width of basement egress windows. Egress opening requirements include:

  • A window with a minimum width of opening of 20 inches.
  • A window with a minimum height of opening of 24 inches.
  • A window with a minimum net clear opening — the actual opening through which a person must crawl — of 5.7 square feet.
  • A sill height no higher than 44 inches above the floor.
  • A window-well floor space of 9 square feet with minimum dimensions of 36 inches wide and long.
  • A permanent ladder or steps if the window well depth is more than 44 inches.

Homeowners may come up with all sorts of reasons why they don’t think they need an egress. But, says Nard, “It’s not about you. It’s about the firefighter or rescue worker carrying gear and wearing an oxygen backpack who has to get through that opening to drag you out in case you are unconscious from a fire or other emergency.” It’s also about anyone who will own the home after you and may use that basement space.

Basement Egress Options

Many manufacturers offer basement egress options. Boman Kemp, based in Ogden, Utah, has its Basement Window Well Systems. Boone Brown, national sales manager, says the Boman Kemp product is a full system that includes everything needed, from double-insulated vinyl window to escape ladder. The system works in new homes as well as retrofits in concrete or block basements. The basic code-compliant system costs about $950 for the do-it-yourselfer.

The Bilco Company, based in West Haven, CT, has its high-density polyethylene ScapeWel terraced-step window-well system that accepts other manufacturers’ windows. The ScapeWel works for new or retrofit work. Bilco’s poured-in-place ScapeView two-piece window system works with the ScapeWel for new home construction. Jim Edgeworth, director of sales and marketing, says the ScapeView now gives its customers one-stop shopping.

Bilco also offers an alternative basement egress. PermEntry is a pre-cast concrete stairwell with steel or maintenance-free polyethylene basement doors. The direct basement access can be installed by a Bilco dealer in a few hours. According to Edgeworth, PermEntry works for both new construction and remodeling. Retrofits involve excavating and cutting a hole in the foundation. The entrance system sits on the footing and is drawn tight to the foundation for a watertight seal.

Up and Out

Here are the basics of a typical basement egress window system:

  • A “buck,” poured into the wall during new construction, creates a frame in the foundation wall.
  • A window well keeps the earth away from the basement window. It can be bolted to a buck or, if a remodel, to the foundation wall.
  • A basement window can be of any style that meets code requirements.
  • Safety grates or grilles keep people and pets from falling into the well.
  • Well covers keep debris from filling the well.
  • Ladders or steps provide a way to get out of the well.

Added Value

Homebuilders like the idea that a livable basement easily doubles the amount of marketable square footage of new homes they sell. Homeowners are finding how easily and affordably they can open up formerly uninviting basements to new uses. Finishing the basement typically costs a third to half of what it would take for above-ground construction.