Interior vs exterior painting — which costs more?

Per square foot of paintable surface, exterior is typically cheaper ($1.50–$4.50/sqft of wall) than interior ($2–$6/sqft of floor). But exterior requires more frequent repainting — every 5–8 years vs 7–10 years for interior. Whole-home exteriors cost $4,000–$15,000 in 2026; interiors $3,500–$8,500. The cost driver split inverts: exterior is 50–60% labor (more prep, taller ladders, weather constraints), interior is 35–45% labor. Two-story homes add 30–50% to exterior cost from staging needs. Stucco and brick exteriors are 20–40% more than wood/fiber-cement siding.