Cost of a home addition – 4 different additions you can choose from.

When calculating the cost of adding an additional room to your house, a lot depends on what space will be used for.

A 10×12 kitchen or bathroom will be more expensive than just an additional bedroom in the home as the price of fixtures and appliances tends to drive prices up.


While a simple kitchen renovation, as of 2019, might run anywhere from $12,000 to $35,000, the new construction costs for other rooms are usually in the $80 to $130 per square foot range. Labor and materials for new home construction anywhere in the United States run, as mentioned, between $110 and $190 per square foot. From that point, you will have a general idea of what construction costs could be, low or high end in your area. Assume a $125/square foot cost for this example. A 10×12 room equals 120 square feet, multiplied by $125, yields a total estimate of $15,000.

In most cases, that amount above will likely be in the ballpark of where the actual cost will fall for most room additions are most likely the same as new construction. Your room will need a concrete foundation, 4 walls, a roof, electrical and plumbing system.

Be advised that this approximate cost is based on simple construction and does not include any materials upgrades you have in mind to make. It includes just the basic standard materials required for additional room to be built.

Before you start, remember to check your local authorities to see if a permit is required for your planned addition as many municipalities regulate any different type of new construction in the city limits.

For the new addition such as described above, the typical costs include: The average basic addition in which a foundation is added, vinyl 1 siding is applied, adequate roofing is done, interior walls are insulated and finished, new hardwood floors or carpet and windows are installed and all electrical and HVAC works (if there is central air in the house) is completed will cost $15,000. The above figures place the cost of the addition at $125 per square foot. This pricing structure assumes that carpenters and electricians charge the standard amount for Fairfield County between $65 to $95 per hour for electricians and painters between 700 and 1300$ per room for painting.

Cost breakdown

What needs to be included:

Architectural design services are the most important part that new addition will require in a structure in a style appropriate to the existing home, and up to code for the neighborhood or area in where the house is located. This should require no more than 8 – 15% of the total set project budget;

Arrange any required demolition, excavation, or site preparation – Costs are variable based on the work that needs to be done.

Pour concrete footings and slab if there is no crawlspace foundation exists for 10×10 room foundation will cost around 2500$.

The roof trusses and support beams are tied into an existing structure – lumber prices will be variable based on the design. The project should require 2×4 wood framing along with OSB structural sheathing;

Asphalt shingles with galvanized metal flashing Install vinyl 1 siding and trim – Average price of $7 per square foot installed, and for the 320 square feet needed, this would total $2200;

Finish ceilings and walls – Drywall throughout would require around 14 panels of 4’x8′ for walls and ceiling at $12 each (plus screws, nails, and finishing compound) for an approximate total of $350 plus approximately 1-2 days of installation;

Fiberglass wall and attic insulation with R-49 and R-28 values respectively value will cost an overall average of $4.00 per square foot (installed) 4-panel primed hardboard door – Average of $178 each plus four hours of installation; Three new windows – Average price of $300-$700 per window, plus installation time of two to five hours per window. Make sure that the windows you will purchase will qualify for tax deductions;

Carpeting – Averages at $25 to $35 per square yard New moldings – Average of $3.00 per foot of installed molding Tie into existing HVAC – Average cost will vary according to the pre-existing system;

Install electrical wiring and lighting up to code – This is going to depend upon the amount of work light fixtures and outlets, but electricians average from $65 to $85 per hour. For a project like that it will be better to price per item installed.

Carpentry up to code – This is going to depend upon the amount of work required and type of roof.

For a project like that is the carpenter to simply quote it based the square footage.

Sometimes, rearranging your existing rooms won’t work and you will just need more space. If your city’s zoning rules allow it, the home additions can be the only solution.

Today, let’s take a look at price point averages for bathroom additions, master suite additions, family room additions, and second-story additions in Fairfield county.

Bathroom addition


Standard bathroom additions cost an average of $13,000 if you adding a bathroom inside of the existing structure like converting a home office to a bathroom or building it in the basement. These numbers are based on a 6-by-8 foot bathroom with a vanity, a regular faucet, a 30-by-60-inch tub, a standard toilet, a linen storage, 12×24 tile flooring, and spotlighting. Adding a bathroom and expanding the footprint of the house will roughly double the price.

Upscale bathroom additions come in at a $70,000 range.

For that amount you can get a 100-square-foot master bathroom featuring a double vanity with quartz counter tops and mirrored integrated lights in the cabinets; a 45-by-45-inch frameless glass shower; a compartmentalized commode, large ceramic tile flooring, an extended HVAC system, including in-floor heating, and general and spotlighting.

Master suite


Standard master suite additions cost will be in the range of $80-90,000 This quote includes a 24-by-16-foot hardwood area with a walk-in closet and a bathroom featuring dual vanities, a 3-by-4-foot stall shower, a freestanding soak tub, a design tile floors, an exhaust fan, and a recessed lights. Upscale master suite additions can go north of $150,000.

That amount will give you a 32-by-22-foot bedroom with a lounging area, custom bookcases, built-in closet units, and a gas fireplace with handcrafted wooden mantle. French doors will be installed. A large walk-in closet with lights on every shelf, mirrors, and storage is also included. In addition to the closet is a bathroom with two separate custom vanities with quartz countertops and mirrors, a frameless glass walk-in shower, a freestanding soak tub, a 5-foot-long wet bar with a sink, a wine refrigerator, a microwave, and custom cabinetry with a quartz or marble countertop. Heated floors, custom wall finishes, and spotlighting are also added.

Family room additions

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Family room additions cost will be in the range of $70,000.

Those numbers are based on a 16-by-25-foot room with siding, an asphalt shingles roof, drywall and insulation, hardwood floors, 180-square-feet of glazing, including exterior doors, windows, and two 3×4 skylights, recessed lighting, and central air systems incorporated into the home’s existing HVAC system.

Second-floor additions

2 story additions are quoted at around $130,000.

The addition includes a 24-by-16-foot, two-story addition to the house with a 1st floor living room and a 2nd floor bedroom and bathroom.

The living room includes a gas fireplace with a wooden mantel, 8-10 windows, an exterior door, and hardwood floors.

The upstairs features a bedroom with a walk-in closet, carpeted floors, recessed lights, as well as a 6-by-9-foot full bathroom with a vanity, a mirrored cabinet, a tub/shower unit, a standard toilet, tiled flooring, and an exhaust fan. An independent HVAC system is also in the price for the new addition.

Final note

While every project and price will be different, the above quotes will give you an excellent place to start when planning your budget for your own Fairfield county home addition or home renovation project. For a more specific quote on your personal project, please don’t hesitate to reach out to us.

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