If you feel like you do not have enough space in your current home but love everything else about it, adding an addition makes your property exactly what you want. Additions come in many shapes and sizes, from tiny bump-outs to full second stories.
For this reason, there is a large range of costs associated with building an addition. The national range is $20,000 - $100,000 with most people spending around $55,000 on a 240 sq.ft. addition on the first floor.
Cost to Add a Room | |
---|---|
National Average Cost | $55,000 |
Average Range | $20,000-$100,000 |
Minimum Cost | $7,000 |
Maximum Cost | $200,000 |
Do not overlook the designing aspect of the addition because it is an important step. Your addition must match the details of your home inside and out to be seamless and to get the most value. Designing also makes the most of the space, so more is done with less square footage.
The general rule of thumb when it comes to the cost of designing a home addition is for the designs to cost between 10% and 17% of the final costs. So, for a 240 sq.ft addition costing $55,000, you pay between $5,500 and $9,350. This varies, depending on the designer and detail of the plans.
There is a range of associated costs per square foot 1 for a home addition, depending on the room’s use, how much existing space is used, and where the addition is built. In general, expect to pay roughly $200 a square foot for a finished addition. Some complex projects may cost more, while very simple ones may cost less. Based on this figure, the following spaces have these costs:
Size | Average Cost |
---|---|
200 sq. ft. | $40,000 |
400 sq. ft. | $80,000 |
500 sq. ft. | $100,000 |
600 sq. ft. | $120,000 |
1,000 sq. ft. | $200,000 |
The size of the room you add has an impact on its total cost, with larger spaces costing more than smaller ones. Keep in mind different types of rooms have varying costs regardless of size. The following room sizes have these costs on average:
Room Size | Average Cost |
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6’ x 8’ | $9,600 |
8’ x 10’ | $16,000 |
8’ x 12’ | $19,200 |
10’ x 10’ | $20,000 |
10’ x 12’ | $24,000 |
10’ x 15’ | $30,000 |
10’ x 20’ | $40,000 |
12’ x 12’ | $28,800 |
12’ x 16’ | $38,400 |
15’ x 20’ | $60,000 |
16’ x 16’ | $51,200 |
20’ x 20’ | $80,000 |
20’ x 40’ | $160,000 |
The room type you add impacts the total project cost as well. Closets, cabinets, plumbing, flooring, and other details make the space more or less expensive than the average cost. Below are some of the average prices for building different rooms based on the most common sizes for each space.
Type of Room | Average Cost |
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Laundry room | $7,000 |
Mudroom | $12,000 |
Sunroom | $45,000 |
Attic | $47,000 |
Bathroom | $47,000 |
Family room | $54,000 |
Living room | $54,000 |
Bedroom | $57,000 |
Kitchen | $60,000 |
Home theater | $87,000 |
The average laundry room is only around 35 square feet, making this more of a bump out than a full addition. Laundry rooms need to be waterproof and usually include cabinetry or storage along with the appliances. This means the costs stay relatively low at around $7,000.
A mudroom addition is usually around 50 square feet, so even with the included cubbies and organizational material needed, it costs around $12,000. The average mudroom includes cabinets, storage, and a durable flooring, such as porcelain or slate 2, in the price.
The sunroom takes on several different forms and building styles. Sunrooms have windows or screens or full walls, depending on your goals. They cost an average of $45,000 for a three-season room.
While it is called an attic addition, this is an attic conversion. It is still a relatively large project with an average cost of $47,000. This includes making sure there is an egress like stairs and working with the lower ceilings, so you may have less space than you imagine with this type of addition.
A full bathroom addition of 48 square feet in a new space costs around $47,000. While this is a small space, it has extra needs for plumbing, raising the costs. Bathroom additions include everything from the shower to the sink and toilet, along with tile and accessories.
The family room comes in many shapes and sizes and is finished in numerous ways. Family rooms are usually informal and made for the family, so they include storage, entertainment areas, and space to spread out. They have an average cost of around $54,000.
The living room is often smaller but more formal than the family room. So while there is less space, it is more likely to have higher-end materials like exotic hardwood 3 or marble floors and nicer features and moldings. Living room additions cost around $54,000.
Bedroom additions may be slightly smaller, but they have additional needs for closets, which raise the cost slightly. Closets, storage, and the necessary lighting drive up the costs closer to an average of $57,000, despite the smaller size.
Kitchen additions often have added costs for cabinetry and plumbing, so while the average size of the kitchen falls between 100 and 200 square feet, the cost averages around $60,000. The average kitchen addition includes flooring, cabinets, counters, appliances, and framing and finishing, driving most of the total cost.
Adding a home theater brings fun and entertainment to your home. They may be added to basements or existing spaces or built onto your home if you do not have the space. Because of the need for acoustic materials and equipment costs, it averages $87,000.
There are many other ways to add to your home to expand your living space, and not all create complete rooms. Each has an associated cost:
Extension Type | Average Cost |
---|---|
Bump out | $5,000 |
Dormer | $5,000 |
Balcony | $5,000 |
Greenhouse | $16,500 |
Cantilever | $20,000 |
Porch | $21,440 |
Modular | $25,000 |
Garage | $35,000 |
In-law | $80,000 |
A bump out is a small extension of an existing room. It adds square footage but at a much lower cost. Because this is not a full room, the costs are considerably lower at around $5,000.
A dormer is a roof extension with a window. It adds extra space to a low-ceilinged room like an attic space. Adding a dormer costs around $5,000.
A balcony is a small deck suspended off the side of the home. This is usually a short and simple project costing around $5,000 on average.
If you do a lot of gardening, add a greenhouse to your property. This project has an average cost of around $16,500.
If you want to add a room to the second floor of a home, extend the space by cantilevering it out over the lower floor. These spaces are not big, but the added support increases costs, averaging around $20,000.
Adding a porch boosts your home’s curb appeal and value while adding outdoor living space. The average cost to add a porch is $21,440.
Modular building is less expensive than traditional because the room is factory-built, delivered, and added onto your existing home. The cost per square foot is lower, and the timeline is faster. Modular room additions cost $25,000 on average.
Having an attached garage improves your home’s value and improves overall function as well. The average cost to add a garage is around $35,000.
An in-law is a fully fitted small building or apartment that is either attached or detached from the rest of your home. Because they often contain kitchens and baths, their costs are higher at around $80,000 on average.
Second story additions have much higher costs than adding a room on the ground level 4 of your home. They involve removing your roof and attic, adding a new floor, walls, and roof for several rooms. This often makes the cost per square foot between $300 and $500, and it is common for the total addition cost to reach $150,000 to $200,000 for homes that are 1,000 sq.ft. or larger. For smaller homes, it costs $90,000 to $120,000.
To add a basement to an existing home, you must give it a new foundation, which means lifting your home, excavating the area, and pouring a new foundation. This has a range of costs, depending on how high the house needs to be lifted and how big the basement is. Expect costs to be at least $50,000 for this project. They may be much higher, depending on factors like your location, soil, and house size.
While every project is different, most have several factors in common that give an idea of where your costs are going during an addition.
Factor | Average Cost Range |
---|---|
Insulation | $0.12 - $6.87/sq.ft. |
Drywall | $1 - $3/sq.ft. |
Roofing | $2 - $3/sq.ft. |
Painting and Finishing | $2 - $5/sq.ft. |
Electrical | $3 - $5/linear foot |
Siding | $3 - $12/sq.ft. |
Flooring | $3 - $20/sq.ft. |
Trusses (roof framing) | $4 - $8 per board foot |
Framing | $9 - $18/sq.ft. |
HVAC | $35 - $55/linear foot |
Doors | $350 - $1,100 each |
Windows | $650 - $1,500 each |
Design Costs | $2,000 - $20,000 |
Keep in mind that this is a general range that nearly all additions include. Specialty rooms like kitchens have additional costs.
The labor portion of your project is dictated largely by which professionals you use and in what capacities. In many cases, you hire a builder or general contractor, and they subcontract out the various specialties, so you are not paying each pro directly. Expect to pay the following rates:
Architect - $150 - $400/hour
Electrician - $65 - $85/hour
Roofer - $2 - $3/sq.ft.
Siding Contractor - $40 - $50/hour
Carpenter - $70/hour
HVAC technician - $50 - $100/hour
Framing professionals - $4 - $10/sq.ft.
Painters - $50/hour
Flooring installers - $1 - $5/sq.ft.
Drywall installers - $1 - $3/sq.ft.
General contractor - $150/hour
You may also need a plumber at $45 - $200/hour if your addition is a kitchen or bathroom.
Every project is different, and many factors impact the cost of your addition. These include the materials used, finishing choices, labor costs in your area, addition size and placement, how you heat and cool the addition, amount of design, and prep work entailed. Any special extras like built-in 5 cabinets or shelves all impact the final addition cost.
Most home additions need a set of blueprints, just like any other major build. A draftsperson works with an architect or builder to produce these. They have an average cost of around $1,200.
Your addition is framed in the same manner and materials as the rest of your home. This provides structure for the space and is integral to the project. Framing has an average cost of around $2,500 for a new addition.
HVAC
In some cases, you may extend things like ducts into your new addition, but in other cases, this stresses your current system too much. It may be a better choice to heat and cool your addition separately. Things like ductless heat pumps are good for additions because they do not tie into your existing system. The cost for a single-zone system is just over $2,000.
Post-Construction Cleaning
Additions are very messy both in the new area and in your existing space. Post-construction cleaning makes your space livable faster. This has an average cost of around $550.
Interior Designer
An interior designer is often helpful when adding a new space because they help you see the possibilities and help furnish it. The average cost of hiring an interior designer for one room in the home is around $5,500.
Expect costs for a 2-story addition to be around $300 - $500 a square foot, while single-story additions are closer to $200 a square foot. Both vary in costs depending on many factors.
The average cost to add a bedroom addition is around $57,000.
You do not necessarily need an architect or draftsman. Use a design/build firm to handle the initial drawings or start with a designer or architect. It is a good idea to have blueprints 6 made.
This depends on the addition’s size, with most costing roughly $200 a square foot.
This depends on the size and type of the addition. In most cases, $200 a square foot is a good estimate.
Cost to add a new space varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.