The Average Cost Per Square Foot to Add an Addition to Your House

Planning and building a new addition to your house is a major undertaking. Home additions are an excellent way to invest money and reap returns years down the road when the market value of the home increases. However, the original cost per square foot for an addition can be high and requires tight budgeting.

Most new additions require entirely new construction, from foundational elements all the way up to new gutters and roofing materials. Essentially, this is so much like building a new house that homeowners can often use new home-building costs to calculate how much they have to spend. In general, in 2011 it cost between $100 and $300 per square foot to build a new house, and this is also true of most additions, not including any furnishings or complicated additions such as bars, but including electricity, plumbing and other necessities.

For some homeowners the line between an addition and a remodel is very vague. Homeowners may find it easier to remodel a home and increase its size at the same time. These remodeling costs are actually very close to new home-building prices, and in 2011 ranged between $115 and $250 per square foot for a single room remodel with addition. A two-story addition tends to start at the higher range of $175, while a multi-room addition often falls in the $150 to $325 range.

There are important variant factors that affect the price of a home addition. Location is one factor, since work and materials will always vary in price from place to place. But the primary determinant is the quality of materials that homeowners choose. Wood costs more than carpet, stone costs more than vinyl, and prices can quickly rise to $300 and beyond with higher-end material choices for the new addition. This can make it difficult to create averages without having some idea of what the homeowner wants.

Adding onto an addition space may not seem like an addition, but in many cases it allows homeowners to change an attic or basement into a new, functional room. In this case, prices are far lower because the basic structure is already there. Basements can cost around $40 per square foot, while attic costs may be similar, lower or higher depending on the existing electrical and plumbing work.