How much does it cost to build a single-family house? For this discussion, we will consider the costs of building a 2,470 square feet, two-story structure with footprint of 24'x50' single family house, which averages $295,000 ​including labor and materials.
https://www.fixr.com/costs/build-single-family-house
The simple answer is, cost. The average cost for a site-built 900 square foot duplex is approximately $138,500. That’s $154 per square foot. Depending on what size, options, and brand you choose American Homes can build your duplex for $59 to $75 per square foot. That means on average you’ll save $60,000 with a modular duplex as compared to a site-built duplex.
http://americanhomestyler.net/duplexes.php
The above figures place this construction at a $117 per square foot cost, though national average stands at $125. This pricing structure assumes that carpenters, masons and excavators charge an average of $70 per hour, electricians between $65 to $85 per hour, painters between $20 and $35 per hour and plumbers between $45 and $65 per hour.
https://www.fixr.com/costs/build-single-family-house
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.
http://homebuildingsmart.com/house-building-cost-per-square-foot/
For instance, a 2-story, 3,200 sq ft single family house should be cheaper to build per sq ft than a 1600 single family house with the same quality standards, So, I'm curious how the overall cost per sq ft would compare if a 3200 single family house was split in two to make a duplex. The footprint would be nothing fancy, 40 feet x 40 feet (4 corners). If it helps, I'm in Pennsylvania. Thanks for weighing in! 1645 sq ft per unit Duplex from Building Designs by Stockton. I believe the following quote, taken from my blog of Monday, February 9, 2009 on Plex Building should answer your question. A four unit house (4 plex) will cost at least 4 X the price of 1, maybe more.
http://buildorremodelyourownhouse.blogspot.com/2010/07/cost-to-build-duplex.html
For the purpose of this discussion we will look at a standard duplex containing four dwellings 900 square feet each. This translates to more than 4000 square feet of construction, and assumes a footprint of approximately 30'x60' for the building.
https://www.fixr.com/costs/build-duplex
(900 square feet, with mid-range materials) Cost to build a duplex varies greatly by region (and even by zipcode).
https://www.fixr.com/costs/build-duplex
Typically, the cost of construction depends on what quality of construction you want. Typical C class construction costs around 700 to 800 rupees per square foot of construction. So a 1000 square foot house should cost between 7 to 8 lakhs to build. Typical B class construction costs around 1000 to 1100 per square foot. So a 1000 square foot house should cost between 10 to 11 lakhs. Typical A class construction costs anywhere from 1500 to 2500 per square foot. So a 1000 square foot house would cost between 15 to 25 lakhs.
https://www.quora.com/What-is-a-good-way-to-estimate-the-cost-of-construction-for-a-residential-house-in-Hyderabad-India
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.
http://homebuildingsmart.com/house-building-cost-per-square-foot/
This sort of building, however, would not come in at the lower cost of $85 per square foot due simply to the excessive amount of construction required. A two-story unit of wooden and masonry construction with four duplex units would run roughly $552,000 in total costs.
https://www.fixr.com/costs/build-duplex
cost per square foot for a duplex
The cost for a duplex is $154 per square foot.