How to Add a Door as an Egress to a Basement

Look for the best wall space for the egress door. Cut the door to open onto yard space or driveway space that sits level, for example. Define the exact dimensions for the door, so you can plan interior remodeling to accommodate it. Place the door so it appears well-spaced with any windows, both inside and outside.

Build a temporary wall to hold up the floor joists. Cut a framing unit consisting of a top plate, bottom plate and temporary studs nailed on 16-inch centers. Construct the framework of 2-by-4-inch boards using a circular saw. Install this temporary wall 2 feet back from the block wall you will cut. Leave room to work, because blocks will need cutting both inside and outside the basement.

Mark the door opening to cut, which must allow room for the framing material included with a pre-hung steel door. Measure the door width and add on an additional ½-inch for wiggle room in the width of the opening, plus 6 more inches. Add the 6 inches for two trimmer studs you will install on each side of the door framing to hold up the header board you will install.

Prepare to remove blocks all the way to the sill plate in most cases. Draw exact cutting lines on the blocks both inside and outside with chalk, making sure they are plumb and level using a 4-foot carpenter's level. Hire a mason with appropriate masonry saws to cut the blocks and chisel neat edges with a masonry chisel. Hang plastic sheeting to separate the door cutting from the rest of the basement to protect from concrete dust.

Construct wood framing to encase the pre-hung door and its surround framing, making sure the header is properly aligned at the top of the door unit. Build the framework using 2-by-6-inch boards that you will place inside the opening for a trial fitting. Secure the framework into the blocks using lag anchors when you are ready to install it permanently. Cut door jamb material to fill exact spacing for the pre-hung steel door. Position the door to close flush with the exterior wall, if the new door will open to the exterior of the house.