What drives home addition costs?

Trying to pin down home addition pricing can feel challenging because every project is completely different. Size matters, but what you plan to put in that new space makes an even bigger difference in cost. Adding a new bedroom or enlarging your family room costs far less than creating a kitchen or bathroom addition, simply because kitchens and bathrooms need expensive plumbing, electrical work, and specialized fixtures throughout the space. Most homeowners spend about $51,047 on their addition according to Angi’s latest 2025 data, but actual costs range anywhere from $4,000 to $160,000 depending on size, type, and materials.