Building Codes: Adding New Openings or Making Structural Modifications

structural modification plans for new window openings

There are many regulations and best practices to consider when making modifications to your home, some of which impact how and where you can add windows, doors, additions or extra rooms. In most parts of the country, including the Seattle area, contractors and builders must follow the International Residential Code (IRC) for One-and-Two Family Dwellings and the International Energy Conservation Code (IECC), both of which define guidelines intended to ensure each home is safe and energy efficient.

Some of these guidelines pertain to window and door openings.

Emergency Egress and Escapes

One of the features a room must have to be categorized as a bedroom is some type of egress or escape option for anyone living or sleeping in the room. As we’ve discussed in a previous blog, this opening needs to meet certain requirements:

  • Be no more than 44-inches from the floor
  • Be a minimum of 24-inches tall, 20-inches wide and have a minimum opening area of 5.7 square feet
  • Be easy to operate

Minimum Sill Height

If a window is located six feet or more above the ground outside the home, the windowsill must be at least 24-inches from the floor of the room in which it’s located. If the window can’t be opened, however, the sill can be closer to the floor, or it can even be a floor to ceiling window.

Safety Glazing Requirements

Not all doors or windows require safety glazing, which is a special glazing that makes the window or glass in a door harder to break. If you have a shower enclosure in your home or you’ve seen one in a hotel room you can safely assume that glass has safety glazing. There are some exterior-facing windows and glass doors that are also required to have safety glazing, including windows that are near swinging doors, sliding patio doors and windows near stairways, ramps and their landings.

Glass in bathrooms and around pools – anywhere with water and slipping hazards – should have safety glazing. 

Properly Framing a Window is Key

Adding a new window opening can be a messy job if not done correctly. It’s not as simple as cutting out a square of drywall, removing the studs in the wall and shoving in a replacement window. Simply put, there’s a right way and a wrong way to add window openings, and the wrong way can result in excessive drywall damage, crooked window openings and potentially compromise wall stability. Some of the things a contractor needs to do when adding a window or door opening include:  

  • Avoid hitting electrical wires or plumbing
  • Temporary floor and roof supports should be put in place prior to cutting into studs on load-bearing walls
  • The top part of the studs in the wall should be removed without damaging the drywall that’s covering them
  • Lower wall stud cripples need to be installed to support the windowsill without damaging the drywall
  • A “kingstud” needs to be installed for added support, along with a header and cripples to replace the top part of the removed studs
  • Extra attention should be paid to structural stability if the window opening is being put in the bottom floor of a two-story home

There’s a lot that goes into safely adding windows or doors to a home to prevent compromising structural integrity or doing more damage than necessary to surrounding electrical, plumbing, studs, drywall and insulation.

You likely won’t want to trust just any handyman or contractor with a job. Make sure to ask for references and review their experience with this particular home modification.

Adding window and door openings is one of Procraft Windows’ specialties. Our experts have added hundreds of windows to homes, so we have gotten the process down to a science. Even if there are unique challenges involved with adding windows to your home, you can rest assured our experienced contractors can develop a solution to make it work.

Give us a call at 206.361.5121 to request a free, no-obligation window opening additional consultation.

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