2019 Home Addition Cost Guide

Average reported cost to build an addition is $35,000-60,000. Because house additions come in a wide range of shapes and sizes, the construction costs vary greatly.

While expensive, building a home addition is a highly rewarding undertaking. After all, you will have the desired extra space, without having to buy a larger house.

Here is an updated list of common house addition costs that homeowners across the US incur, to help you plan your budget.

Cost to build 420 sq. ft. Addition:
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Mid Range
High End

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How Much Does A New Addition Cost?

The price for a large house addition that includes a kitchen or bathroom is comparable to building a small home. On average, addition cost per square foot is $125-400.

Home Addition Costs

Obviously its size and location will be the primary cost drivers, but there are hidden factors that may jack up the price as well.

These include: complexity of architectural design, quality of materials and finishes, permits and building inspections, just to name a few.

Here is what you can expect to pay to add on different types of rooms. This estimate includes: new foundation, roof, siding, proper wall insulation, new windows, flooring, electric, HVAC and finishing work.

– Typical bathroom addition cost: $25,000-40,000 for a 5×8 room with a tub or shower enclusore

– A spa-like, master bathroom: as much as$80,000 plus

– An average size, kitchen without the luxury bells and whistles: $25,000-50,000

– Upscale kitchen design: as high as $100,000+

– 10×15 bedroom (without a bathroom): $20,000-35,000

– Room addition cost (400 sq.ft.): $30,000-100,000

– First floor addition (800-1,500 sq.ft) with multiple rooms: $150,000 +.

– Second floor addition with multiple rooms (1,500 sq.ft.): $200,000-475,000

Pro Tip: the larger the size of the space you are looking to build, the less you will be paying per square foot.

If you are planning a complex project, such as a two-floor addition, you will need to hire an architect and budget for his fees. These can be as much as 10-15% of the total cost. Some people save money by hiring a design-and build firm, that has a staff architect and includes the design fees into the final price.

Expect to spend $1,200-2,500+ on blueprints and $2,000-5,000+ on architectural design.

While these prices may seem extremely high and out of your budget, you can pay for the addition by getting a home equity loan. In fact, that is what the majority of homeowners do. Another financing option is to get a construction loan.

The key to setting a reasonable budget and sticking to it is to identify and manage all the anticipated remodel costs in the beginning stages of the project.

To be on the safe side and avoid running out of funds, its best to budget 15-20% of the total cost for unforeseen expenses.

Factors That Drive Up Addition Cost

Cost of Building Home Additions

There are a number of factors that may significantly increase the total cost of an addition. For example, if you want a new bathroom or kitchen, you will need to install an entirely new plumbing system. This will be thousands of dollars. One way to save money on this is to connect to the existing plumbing system, if the addition design allows for it.

Another significant expenditure will be hiring a mason to pour a level concrete floor, if you are planning to build a garage.

You should also budget at least $1,500-4,000+ extra to fix the landscaping around the new addition.

You will need to pull building permits for most of the construction and remodeling jobs. Each permit will be a few hundred dollars. Also, you may need to run special kinds of tests, such as soil testing, which may cost $1,000+

Keep in mind that while your general contractor will be doing most of the work, and can most likely give you a discount if the scope of work is large enough, you will still need to hire professional contractors to complete specialized tasks. These may include a roofer, electrician, plumber, etc. To get the best rates, be sure to get quotes from at least 3 different contractors.

Lastly, the quality of materials you select will also make a great difference in the final price. Choosing, high quality, brand name, or luxury building materials can significantly drive up the cost. Here, you need to carefully consider your total budget and what you are planning to achieve.

Sometimes, going for more expensive materials is justified because of their improved longevity and durability, as opposed to spending a lot more money to have an upscale look. For example installing a metal roof instead of asphalt shingles may cost $10,000-15,000 more, but will offer superior weather protection for the lifetime of your house.

Cost to build 420 sq. ft. Addition:
Low End
Mid Range
High End

See costs in your areaStart Here - Enter Your Zip Code

About Yelena G

Yelena G. has been working in the remodeling and construction industry for over 15 years. Her focus is on construction planning and design as well as project cost estimating. Yelena also has a personal interest in interior design, as well as in unique DIY remodeling projects. Read more about Yelena

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4 thoughts on “2019 Home Addition Cost Guide

  1. Garry

    Thanks for a realistic price reality. Been doing this for years and still scratch my head pricing additions. Cost of living is like a mirage .

  2. Soppheap Thong

    plan to add a story with 4 bedrooms, 2 baths and family room on the top of 1471 sq.ft house. how much is total cost?

    In Garden Grove, California, does it required 3 cars garage for more than 5 bedrooms house ?