Check local building codes and plan the required dimensions for the brick well. Many municipalities provide minimum dimensions for window wells, especially if they are being built around egress windows. If the window opens to the outside, the well should be large enough to accommodate the open window. The wall should extend at least 4 inches above the ground and at least 8 inches below the window.
Excavate the area for the window well. The brick window well should have a footing of poured concrete that extends below the frost line to prevent frost heave. The footing should have the same depth as the planned well's width, or the width of two bricks, and the footing should be twice as wide as the window well wall.
Build or assemble the forms for the poured concrete footing. Secure and brace the forms with wooden stakes or 2-by-4s. Coat the inside of the forms with form lubricant or motor oil.
Place rebar in the forms to act as a reinforcement for the footing and window well. This may only be necessary if the well, which is built to act as a retaining wall, will be more than a few feet tall. Run two or three lengths of rebar through the footing, tying pieces together at corners with rebar ties. Place vertical lengths of rebar that will extend nearly to the top of the wall. These pieces should be placed every few feet in the center of the footing, as the bricks will be laid on either side of the upright rebar.
Pour concrete into the forms and let it cure adequately before removing the forms and proceeding with window well construction.
Prepare to lay the bricks. Snap chalk lines on the top of the footing to mark where the bricks will be placed. Do a dry run first and cut several bricks to allow staggering of joints between layers.
Prepare mortar and use a trowel to place and spread mortar on the first few feet of the footing between the chalk lines.
Lay bricks in the mortar. Mortar the end of each brick as it is placed to secure the first brick to the wall and each subsequent brick to the brick before it. Fill in the center space between bricks. Wiggle each brick as it is set to reduce trapped air beneath the brick. Use a level to check the bricks for evenness regularly and adjust bricks as needed. Continue laying bricks until the first course is completed.
Place mortar along a few feet atop the first course of bricks. Work in small sections, increasing the size of sections as the work becomes more familiar.
Lay bricks for the second course in the mortar. The bricks must be staggered between courses to keep vertical joints from aligning. Continue building up the well in this manner.
Insert wall ties every few feet, beginning about the fourth course, to span the width of the two bricks for additional reinforcement.
Continue building the window well until the top of the planned wall is reached.
Place capstones on the window well. Capstones may consist of flat rocks, blocks or bricks aligned so that their ends are facing out. Place the capstones so that they slightly hang over the face of the lower bricks.
Waterproof the exterior of the window well where the bricks will be in contact with soil and soil moisture. Use a suitable waterproof membrane or paint on a tar or asphalt-based coating according to manufacturer instructions.
Lay a 4-inch perforated PVC drain pipe along the exterior of the well at the depth of the footing. Direct the drain pipe to an outlet or foundation drain, or otherwise extend it away from the structure.
Fill the base of the window well interior with gravel, leaving about 4 inches of space below the window. Add a layer of gravel atop the perforated drain pipe.
Backfill the remainder of the space around the exterior of the window well.