How much does it cost to add a new space?
Adding on to any home, whether it is an expansion of the existing "footprint" or an entirely new level is a very complex project. For this discussion we will examine the requirements and general costs associated with adding a single-story 192 square foot (12'x16') room. This type of project will not be considered a "DIY" project in the least, and several contractors will be necessary for the job (carpentry, installation, electrical, etc.).
For the new addition such as described above, the typical costs include:
- According to Hanley Wood and their "Remodeling" magazine 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 carpet and windows are installed and all electrical and HVAC works is completed will cost $23,804. The resale value of this update would hold at $19,757, or an 83% return on investment.
- The above figures place the cost of the addition at $124 per square foot. This pricing structure assumes that carpenters charge an average of $70 per hour, electricians between $65 to $85 per hour, and painters between $20 and $35 per hour.
What needs to be included:
- Architectural design services to ensure that new addition is housed in a structure in a style appropriate to the existing house, and up to code for the neighborhood or area in which the home is located. This should require no more than 10 - 17% of the total building budget;
- Arrange any required demolition, excavation, or site preparation - Average costs are going to vary according to the level of work necessary;
- Pour concrete footings 2 and slab if no crawlspace foundation exists - Average price of concrete is $75 per cubic yard, with piers and the full slab it that would require roughly 14 cubic yards and would cost at least $1050;
- Build roof trusses 3 and support beam system and tie into existing structure - lumber prices will vary as will the design used by the carpenters constructing the new space. The project should require 2x4 wood framing along with OSB structural sheathing;
- Asphalt 4 shingles 5 with galvanized metal flashing 6 - Average of $80 to $100 per square of 50-year shingles 5. Total cost of $450, plus installation time of at least 16 hours;
- Install vinyl 1 siding and trim - Average price of $7 per square foot installed, and for the 514 square feet needed, this would total $3600;
- Finish ceilings and walls - Drywall 7 throughout would require 20 panels of 4'x8' for walls and ceiling at $9.80 each (plus screws, nails and finishing compound) for an approximate total of $250 plus approximately 24 hours of installation;
- Fiberglass 8 wall and attic insulation with R-49 and R-28 values respectively value will cost an overall average of $2.00 per square foot (installed) for an approximate total cost of $825;
- 1 - six-panel primed hardboard door 9 - 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. Be sure that the windows purchased will qualify for tax deductions;
- Carpeting - Averages at $15 to $25 per square yard (with padding 10 and installation) totals $533;
- New moldings - Average of $3.00 per foot of installed molding for a total of roughly $850;
- Tie into existing HVAC - Average cost will vary according to pre-existing system;
- Provide electrical wiring and lighting to code - This is going to depend upon the amount of work required, but electricians average from $65 to $85 per hour. This project might be priced on a per item basis, or the electrician might simply base it on the square footage; and
- Provide carpentry to code - This is going to depend upon the amount of work required, but carpenters average $70 per hour. This project might be priced on a per item basis, or the carpenter might simply base it on the square footage.
Enhancement and improvement costs
- 6 recessed ceiling lights; and
- Painting of trim and walls.