🇺🇸 United States · Construction cost guide · Updated 2026
How much does it cost to build a duplex in the United States?
Building a duplex in the United States typically costs $764,400 to $1,419,600 in construction cost — roughly $137–$254 per ft² ($1,470–$2,730 per m²) over 5,597 ft² (520 m²) of floor area. That excludes land, professional fees and statutory charges.
The United States is a high-cost construction market by global standards — it is the baseline our construction cost index is measured against (index 100). This page prices a duplex — two-unit dwelling over two floors, shared party wall, separate services to each unit — at 520 m² of gross floor area, then breaks the cost down element by element so you can see where the money actually goes. Costs are quoted in USD for comparability; the local currency in the United States is USD ($), and a bill of quantities generated from your own drawings is priced in USD using the CSI MasterFormat divisions standard.
What is being priced
The figures on this page price a duplex in United States at 5,597 ft² (520 m²) of gross floor area over 2 storeys, specified as two-unit dwelling over two floors, shared party wall, separate services to each unit. Construction cost only — land, professional fees, statutory charges, utility connections and loose furniture are all excluded, and together commonly add another 15–30%.
Cost by specification level
| Specification | Construction cost (USD) |
|---|---|
| Basic / low-cost finish | $550,368 – $1,022,112 |
| Standard finish | $764,400 – $1,419,600 |
| Premium finish | $1,108,380 – $2,058,420 |
Where the money goes
Elemental split of construction cost for a duplex of this type. Percentages are concept-stage cost-planning proportions; the ranges below apply them to the totals above.
| Element | Share | Cost (USD) |
|---|---|---|
Substructure & foundations Excavation, strip footings, hardcore, blinding, DPC and ground slab. | 15% | $114,660 – $212,940 |
Walling & superstructure Masonry, lintels, ring beam and any suspended floor. | 22% | $168,168 – $312,312 |
Roofing Trusses or rafters, covering, ceilings, fascia and rainwater goods. | 14% | $107,016 – $198,744 |
Internal finishes Plaster, screed, floor and wall tiling, ceilings and painting. | 18% | $137,592 – $255,528 |
Joinery & fittings Doors, windows, cupboards, worktops and ironmongery. | 9% | $68,796 – $127,764 |
Services (plumbing & electrical) Wiring, distribution board, fittings, water reticulation, sanitaryware and drainage. | 14% | $107,016 – $198,744 |
External works & preliminaries Site setup, supervision, paths, boundary works and connections. | 8% | $61,152 – $113,568 |
No drawings needed
Get a priced bill of quantities for your own house
The figures above are benchmarks for United States. Tell us how big your build is and get the itemised version — every material and trade measured and priced in USD, — without needing architectural drawings.
Building duplexes in United States — frequently asked
How much does it cost to build a duplex in the United States?
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Building a duplex in the United States typically costs $764,400 to $1,419,600 in construction cost — roughly $137–$254 per ft² ($1,470–$2,730 per m²) over 5,597 ft² (520 m²) of floor area. That excludes land, professional fees and statutory charges. At a basic specification the same building lands nearer $550,368–$1,022,112; at a premium specification, $1,108,380–$2,058,420.
What is the cost per square foot in the United States?
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About $137–$254 per ft² ($1,470–$2,730 per m²) for this building type at a standard finish. Per-m² rates rise with storey height (frame, cores and cranage) and with specification, and fall on simple single-storey plans.
What is the biggest cost item?
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Walling & superstructure — about 22% of construction cost, or $168,168–$312,312 on this build. Masonry, lintels, ring beam and any suspended floor.
Does this include land, fees and furniture?
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No. These are construction costs only — materials, labour, plant and site preliminaries. Land, statutory approvals, professional fees, connections, landscaping and loose furniture are all additional, and together commonly add 15–30% on top.
How do I get an accurate figure for my own plans in the United States?
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Benchmarks give you the ballpark; a measured bill of quantities gives you the number. Upload your dimensioned floor plans to Enormous Buildings and get an itemised, source-cited BoQ in USD in the CSI MasterFormat divisions format that the United States quantity surveyors and lenders expect — free to preview.
Why do build costs vary so much between countries?
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Three things dominate: labour cost, how much of the material basket is imported, and the code requirements the building must satisfy. The United States sits at index 100 against the United States at 100, which is why the figures above differ from what you'd see quoted for the same building elsewhere.
Other build costs in United States
For contractors & quantity surveyors
Tendering in United States every month?
A one-off bill suits a single project. If you tender regularly, a monthly plan brings the cost of each bill right down, with no card to re-enter each time.