Wool carpet installed runs $5.50 to $23 per sq ft, four to six times the cost of mid-grade synthetic carpet. It lasts four to six times longer. The cost per year of service is roughly the same as premium nylon, sometimes slightly cheaper. Where wool wins decisively is on softness, thermal comfort, and the way it looks five years in. Where it loses is in humid environments and in any room where the household treats the carpet as a consumable item.
Wool carpet is expensive at install and cheap over time, which inverts the usual carpet-buyer instinct that cheaper-is-better. Run the cost-per-year arithmetic on a typical 12×12 bedroom and the picture clarifies. A budget polyester install at $480 ($3.33/sqft installed on 144 sqft) lasts roughly 7 years in a master bedroom, so cost per year of service is about $69. A mid-grade nylon install at $850 ($5.90/sqft) lasts 12 years, so cost per year is about $71. A 100% New Zealand wool install at $1,800 ($12.50/sqft) lasts 22 years, so cost per year is about $82. The premium wool option is the most expensive per year of service, but only by about 15 percent over nylon. For low-traffic master bedrooms the premium is easy to justify on comfort grounds alone.
The 80/20 wool-nylon blend changes the maths in wool's favour. At roughly $1,200 installed for the same 12×12 bedroom (about $8.33/sqft) and a 22-year lifespan, the cost-per-year is $55, lower than budget polyester. The 80/20 blend is the best value tier in residential wool carpet, and it is what most informed homeowners eventually land on after comparing the options.
The carpet industry recognises three quality tiers of wool based on origin. New Zealand wool is the top tier, prized for unusually long, strong, fine fibres with high natural lanolin content. The fibre length means stronger spun yarn with less shedding, and the lanolin provides inherent stain and water resistance without chemical treatment. New Zealand wool is the source of choice for premium brands (Karastan, Stark, Crucial Trading) and adds roughly 20 to 35 percent to the material cost vs UK wool.
UK wool (most often British Wool Marketing Board certified) is the second tier and excellent for budget and mid-grade wool lines. Fibre length and lanolin content are slightly below New Zealand but the carpet still performs well. Unspecified wool (labelled simply "wool" without origin information) is usually a blend of sources, often including coarser wools from China or Argentina that perform less well over time. If wool origin is not stated on the spec sheet, ask. Reputable dealers will tell you, sometimes proudly. A non-answer is a signal to compare with another dealer carrying spec-clear wool lines.
Wool absorbs about 30 percent of its weight in moisture from the air without feeling wet, which makes it a thermal-comfort asset in dry climates and a problem in humid ones. The list of places wool should not be installed is short but important. Basements, regardless of climate, because of slab-derived vapour. Coastal Gulf and Atlantic homes where indoor humidity routinely exceeds 65 percent. Bathrooms and rooms directly adjacent to bathrooms where steam exposure is regular. Mudrooms and entries where outdoor moisture enters. High-pet-traffic households where the carpet will see frequent spot-cleaning at scale; the wool-specific cleaning requirement makes routine spot maintenance harder than with synthetic. Outside these cases, wool is an excellent choice in any room that can sustain the install cost.
Wool carpet has different cleaning chemistry from synthetic. High-alkaline cleaning solutions, hot-water extraction at synthetic-appropriate temperatures, and many off-the-shelf spot cleaners will damage wool fibres or affect the dye. Professional cleaning of wool carpet requires cool water, low-alkaline pH cleaners (typically pH 5 to 8), and lower extraction temperatures than nylon. Most professional carpet cleaning services charge 15 to 25 percent more for wool-rated cleaning, so $0.35 to $0.60 per sqft vs $0.30 to $0.50 for synthetic. Annual cleaning on a 1,000 sqft install runs $350 to $600. Across a 22-year wool carpet lifespan, total maintenance cost is $7,700 to $13,200, a meaningful slice of the carpet's lifetime cost-of-ownership. Budget for it when comparing wool to nylon, because the synthetic cleaning cost will be slightly lower across the same period.