Carpet types: Plush or cut-pile carpet has loops trimmed off so that yarn ends poke up. Saxony plush, one of the most popular varieties, has short tufts that are densely packed. While a popular choice, plush carpet doesn't tend to wear as well as berber (or high level loop) carpet.

Berber (or high level loop) carpet creates a nubby texture with complete yarn loops that stand upright. Looped carpet tends to wear better than cut-pile, such as plush, where the loops are cut.

Wool generally is considered to be the ultimate fiber. It costs two to three times the price of synthetics, but it's particularly comfortable, durable and natural in appearance. It is resistant to soil, but when soiled may be particularly hard to clean. Be aware that direct sunlight will fade wool fiber over time.

Synthetic fibers are made from several artificial materials. Although these are given trade names, generically they are called nylon, olefin, polyester or acrylic. Nylon is the most popular because of its durability, although it can be damaged by prolonged exposure to sunlight. It is less costly than wool, one of the most expensive of the synthetic varieties.

Olefin is a low cost, easy-care material that's often used as an indoor (basements, rec rooms) and outdoor (patios)carpet. It is usually pre-treated to resist fading. Polysters are softer but a bit less durable and more inexpensive than nylon. They can be damaged by heat and sunlight.
Acrylics resemble wool more than other fibers and resist fading. They are more expensive than nylon.

Sisal carpet is made from a natural fiber derived from a cactus plant that's stronger and more durable than other natural fibers. Sisal carpets and area rugs are highly durable, earthy and rough textured like jute.

Stairs: The type and amount of stairs you have will, of course, affect your carpeting budget. The national cost average ranges between six and nine dollars per stair step for a fully carpeted stairway.

The cost goes up significantly if you want runner-style carpeting, which is carpet that runs up the middle of the stairway. That's because even though less carpeting is used, more labor is involved.

Curved stairways are also more expensive to carpet, and the cost can also vary, depending on whether the staircase has a closed riser or open riser.

Adding Padding: Carpeting is applied over padding most of the time (in an estimated 90 percent of residential jobs) for two basic reasons: comfort and to prolong the carpet's life. While carpet pad does add to the cost of carpeting, the fact that it extends a carpet's lifespan makes it more than worth the additional cost. The added cushioning provided by padding makes it better able to withstand the wear of foot traffic and more comfortable to walk on.

Even if your old padding seems to be in good shape, it's recommended that you replace it if you want the carpet warranty to stay intact. Most carpet manufactures will not honor warranties if old pad is used.

Padding: The type of subflooring you have does not impact the choice of padding. The two most popular padding options are 7/16-inch or 3/8-inch thick.