Basements are a valuable part of any new home, with benefits far outweighing the costs. About half of all new homes in North America are built with basements, and the rest could be. Concrete is the material of choice for basement construction, with 98% of North American basements built of one of many available concrete wall systems.
WHY BUILD A BASEMENT?
Basements provide inexpensive space for many uses. A basement's sturdiness and location make it ideal for housing mechanical equipment such as furnaces, water heaters, and other utilities. These same properties make it an excellent choice for recreational space, storage areas, workshops, or hobby rooms. Basements typically house main electrical lines, plumbing, and ductwork, making these easily accessible for changes and repair. The sheltering properties of belowgrade space make basements “safe havens” for occupants during hurricanes, tornados, and severe thunderstorms. With a few upgrades, basements can be transformed into entertainment centers, offices, or extra bedrooms for a growing family. This provides a homeowner future expansion potential without the cost of constructing more floor space aboveground, and also can increase substantially the resale value of a property.
HOW MUCH DOES BASEMENT SPACE COST?
Building almost any home requires digging, from a few inches to a few feet. By increasing the digging to 6 to 8 feet, forming walls of the desired height, and pouring a concrete slab at the bottom, a contractor can make a foundation into a full basement. The incremental cost can be as little as $10 per square foot over the cost of a shallower, stem wall foundation, or $20 per square foot over the cost of a simple slab on grade—far below the cost of constructing more space in the aboveground portions of a house.
WHY IS MY BASEMENT BUILT OF CONCRETE?
For basement construction, concrete is by far the product of choice. Concrete provides a permanent, stable base for a house to rest on and creates an enclosed space protected from the ground, rodents, and weather. Sturdy concrete walls are highly resistant to shifting or sagging under ground and water pressure, often for a century or more. When necessary, strength can be enhanced by increasing wall thickness and embedding steel reinforcing bars inside the concrete. Concrete does not rot, warp, rust, deteriorate, or provide a food source for mold in the presence of water or moisture. Concrete doesn't burn and can't be eaten or damaged by termites, insects, or vermin. Properly designed concrete walls keep out water, radon, and outside noise. They also can be constructed with a durable architectural finish and high insulation value.
WHAT ARE THE DIFFERENT WAYS TO BUILD A BASEMENT OUT OF CONCRETE?
Cast-in-place concrete using removable forms (sometimes called “poured concrete”) produces an economical wall with a hard, durable surface on both sides. Concrete masonry (block) walls can provide an architectural surface in many different colors and textures, for a distinctive exterior appearance and an attractive interior finished wall. Insulating options are available for both cast-in-place and masonry wall systems, depending on desired results. Insulating concrete forms create a highly energy-efficient wall that is ready to finish with traditional gypsum wallboard on the interior surface. Solid precast panels are pre-insulated, ready for wallboard, and go up rapidly in almost any weather. Some precast panels have insulation “sandwiched” into the center of the wall, providing a smooth finish that doesn't require wallboard. Autoclaved aerated concrete blocks are made of a lightweight concrete with good insulating properties.
WHAT'S THE BOTTOM LINE?
A basement provides valuable, versatile space for a new home at a relatively small additional cost. Plan your space with an eye toward future use. Look for proper water control measures, and verify that the results match your plans. Concrete can create strong, high-quality walls, with different systems offering a variety of properties to meet your needs.
For more information, contact the Portland Cement Association at 5420 Old Orchard Road, Skokie, IL 60077. Call 847-966-6200 or visit www.cement.org.