Average house building cost per square foot can be very complex to estimate. Your home will vary in price from others according to size, but also according to methods and materials used in construction, and how much of the job you will do yourself. Materials account for about one third of the actual price of a home. Another third goes to the labor of subcontractors, and one third goes the labor and management skills of your general contractor. Parts of your home also cost different amounts. Another way to break down costs is, foundation and labor for foundation, shell materials, labor for shell, Electrical, plumbing, and finishes.
House Building Cost Per Square Foot Factors
House Building Cost Per Square Foot Factors: Grading and Lot Preparation
Variables include the amount of leveling needed, and the cost of trying to preserve trees. Cost for grading and lot prep on a level lot range from $400 – $800, while a steep, wooded lot would cost up to $4000. In addition cut and backfill on a mountain lot can cost $5 – $30 per cubic yard of earth moved.
House Building Cost Per Square Foot Factors: Foundation Costs
The difference in cost between slab, crawl space and basement vary. The need for each varies by climate. In Northern states, one might as well have a basement, because the frost line is so deep, that the foundation must be sunk about 7 feet anyway. In the dampness of the Southeastern states, it is better to have a crawl space, especially in red clay soil or a high water table. Basements can be quite costly to water proof. Slabs work OK in some areas, but I do not think it is wise to run plumbing pipe under the slab.
Slab – A concrete slab will cost about $4 per square foot. So if a the slab is 24 x 30 foot, then your slab would cost $2880. This price varies though in different areas, and with the cost of concrete.
Crawl Space – The cost is based on the perimeter of the home. While local prices and soil conditions make this cost variable, we can make a rough estimate. Trenching is approximately $2 per linear foot. Reinforced concrete continuous footings cost another $10 to $15 per linear foot. Add to this about $6 or $7 per line foot for a concrete block foundation wall. Supports in the center may be needed too, but to estimate figure $18 – $24 per linear foot of the parameter. For example if the foundation will be 24 x 30 foot, then you would multiple108 by $18 and then by $24. We get the number $1,944 and $2592. Adding about $500 for additional support pillars under the house, should leave you with a good idea of how much a crawl space foundation will cost.
Basement – Unfinished basement costs in the US vary from $12 to $28 per square foot. Soil conditions vary and it could be even more in some areas. Of course unlike with a slab or crawl space you are adding usable square footage.
House Building Cost Per Square Foot Factors: Shell Costs
The cost of a shell can be as low as $20 to $30 per square foot. Even expensive contractors can put up a shell for a fraction of the price of completing the home. Consider the difference in the amount of time he will spend on your home. Of course a shell is just a wood frame with sheathing, windows, doors, roofing, and siding. Some shells may include insulation and some even include dry wall, but the interior is still unfinished.
House Building Cost Per Square Foot Factors: Plumbing, HVAC, and Electrical
These costs vary considerably with quality, however installation of these things for an average modular home, can be $20,000 or more. Professional licensed electricians are absolutely necessary, and it’s generally necessary to hire professional plumbers and HVAC experts.
So if we add this up, the foundation and site prep is going to cost roughly $5 per square foot. The shell will cost $20 to $30 per square foot, and the HVAC Plumbing and Electrical will cost add about $10 to $15 per square foot. So, we have $35 to $50 per square foot to build a shell, with a crawl space foundation, which is outfitted with electricity, HVAC and plumbing.
House Building Cost Per Square Foot Factors: Interior Finishes
Finished homes cost, on average, cost between $80 and $130 per square foot. There is a substantial cost involved apparently between the finished home, and a shell. A do it yourselfer with an eye for bargains on floor coverings could finish the home for significantly less than the contractor. At least half of the cost of your home will be accrued in the finishing touches. If you wish to finish out the shell yourself, you could possibly spend only $20 per square foot. That is a substantial savings.
The fact is that finishing the interior is very time consuming for the contractor. He’s not taking advantage by expecting to be paid for six months work, after the shell is complete. Many subcontractors are also being employed during this period. Carpet layers, painters, and drywall people are paid during this time, and scheduling them can be a headache. Some of the largest expenses, or at least the greatest variables in costs, can be the kitchen and bath(s). Cabinetry, appliances, and plumbing fixtures can vary considerably in cost.
Finishing the interior of a home can be a time consuming and painstaking process, however if you feel comfortable completing your own home, it is possible to contract for a shell and save $25 to $60 per square foot. Which you choose to do is completely up to you. In general the interior of your home is not as crucial as the structure, but if you are the type to be really upset if things aren’t just perfect, you may be better off to leave it to the pros. If you are hard pressed on the budget, you’d be better off completing the house from a shell with your own labor. Your house building cost per square foot is largely dependent on your choices.