Cost to Build home per square Foot
Estimate of building a home can be all over the place. I get it. But hope the following can help some people out in estimating some costs on their own project...
I have seen homes and apartments sell in the Inland Empire and Antelope Valley of Southern California for less than $100/SF and include the land. I've seen homes and apartments in Texas, etc also sell for less than $100/SF including the land.
Contractors and home builders can become millionaires and even billionaires (ex. Mr Broad). It is the ignorant consumer such as me that feed into that whole industry. Yet, it is really just simple math.
What you really want to know is how much is materials and labor for a pre-finished house. That means before you pick the flooring material, window quality, appliances, cabinet quality, counter tops, other fixtures. Those finished items are what can really change the cost per square foot.
But if you just can figure out the pre-finished house cost, then you can better understand if the contractor bid is out of line. Plus, you can then better plan your budget on the cost of flooring, windows, fixtures, etc.
I don't know how to figure cost for a foundation footings (maybe someone can contribute that information), but I can at least estimate the cost for lumbar to construct a 12 x 12 x 8foot high ceiling room. Twelve foot 2x6 Douglas Fir about $7.50 each.
8 x 4 foot plywood sheet (15/32 thick, pressure-treated rated sheathing) is about $27/each. (There is cheaper plywood if you like).
8 x 4 drywall sheet high-strength lite gypsum board (1/2 inch thick) is about $15/each. (There is cheaper drywall if you like).
So, for a common 12 ft x 12 ft x 8 ft ceiling room: (Not accounting for cut outs for doors and windows, switches, sockets, etc.):
about 36 8-foot 2x4s vertical studs (spaced every 16 inches around the four walls) x $2.50 = $90
about 18 8-foot 2x4s for the perimeter footing and double-top header x $2.50 = $45
about 11 12-foof 2x6 beams as your foundation beams spaced 16 inches and two end caps (if having a raised foundation) x $7.50 = $85
about 12 8x4 plywood around the exterior walls x $27 = $324
about 5 8x4s plywood for the flooring x $27 = $135
about 12 8x4 drywall sheets for the interior walls x $15 = $180
about an extra 8 8-foot 2x4s to cut into 15-inch pieces to brace all the studs and floor beams x $2.50 = $20
So lumbar is about $880 +/- for that pre-finished room.
Oh, if you want a ceiling you have to add either 9 more 2x6 (($68) or 9 more 2x4 beams ($23), and 5 more drywall sheets ($45).
So lumbar is about $1000 +/- for that very pre-finished merely framed 12x12 8-foot ceilingroom.
I've seen a few Youtube videos about framing. Only including the actual time to use a nail gun to assemble the floor beams, nail the plywood flooring, and wall studs with footing and header (not yet counting for the plywood sheathing and drywall), it takes less than one hour to nail the pieces together for each wall, and the floor. It is not rocket science. Cutting the braces and nailing them between the floor beams and wall studs probably takes about another 2 hours.
Day #1: So for framing that room should take 1 day.
$60/hour rate x 8 = $480 labor. for walls and floor framing.
Day #2: Next day exterior plywood nailing should be about 1 hour per wall. half day labor = $$240
Maybe another half day to do the ceiling beams =$240.
Also put in your wall insulation: R-13 Owens Corning Kraft 15-inch x 32 feet roll is $13/each x 9 (cut to 36 pieces of 8-feet high length to put between the wall studs) = $120.
If you add insulation for under plywood floor between the floor beams then just calculate what insulation you are going to buy with the square footage to cover 144 square foot subfloor area.
Before you drywall, need to coordinate electrical, plumbing, socket and switches placement, etc.
Maybe someone can add to this rough estimate by figuring out those service costs.
Day#3 (Which is likely days after electrical, plumbing, etc work) Drywall the walls and ceiling is likely a whole day's work at $60/hr = $480 .
Nails varies from about $10/1000 nails to $40/1000 nails. Minor cost.
So I listed the above:
$1000 +/- for lumbar
$120 +/- for insulation
$1500 +/- labor (three days of work, not including electrical, plumbing, etc.)
If it takes more days of labor, then just make the adjustment in cost.
Hope someone can contribute the costs of foundation footings versus slab foundation, electrical and plumbing labor costs, and roof laborcosts, etc.
You can see that materials for a pre-finished structure is really not the main costs. It is the labor.