What does it cost to build a house in the Triangle, and what do families forget?

The short answer: a builder's contract to build a house on land you already own ran a median of $388,100 across the South in 2025, according to the Census Bureau. That number leaves out your lot and later changes. Permits, septic or well, and water and sewer hookups can add thousands of dollars, so budget for them from the start.

What does it cost to build on your own lot?

The best public yardstick comes from the Census Bureau. It tracks "contractor-built" houses: homes built for the owner to live in, on land the owner already has, with one general contractor in charge, according to the bureau's survey definitions. The contract price is the price on the original contract. It generally does not include later changes, such as change orders.

In 2025, the Census contract price table put the median contract price for these houses in the South region at $388,100, with an average of $558,400. North Carolina is in the South region; Census gives no state or Triangle figure. Nationally, the 2025 median was $404,000 and the average $576,500. A year earlier, in 2024, the South median was $336,300.

A few cautions. The table notes say the contract price leaves out the value of the improved lot. And the 2025 South figures carry relative standard errors of 8% to 9%, so treat them as estimates, not price tags.

Where does the money go?

The National Association of Home Builders surveys builders about homes built for sale, so its numbers include the lot and selling costs and measure something different from the Census contract price. In its 2024 Cost of Construction Survey, construction made up 64.4% of the average sales price, the highest share since the series began in 1998. The finished lot was 13.7%.

Within construction, NAHB found interior finishes were the biggest slice at 24.1%, followed by major system rough-ins (plumbing, electrical and heating and cooling run inside the walls) at 19.2%, framing at 16.6%, exterior finishes at 13.4%, foundations at 10.5% and site work at 7.6%.

What permit and septic fees should you expect?

First, find out which office issues the building permit for your lot. Towns and counties set their own fees, so the numbers below depend on where you build.

Where Wake County issues the permit, its fee schedule charges $75 plus $0.25 per square foot of gross floor area for a new home. Gross floor area is measured inside the exterior walls, garage included. One permit covers all trades.

In Johnston County, the building permit fee schedule (headed effective July 1, 2024, and last updated November 4, 2025) lists a $50 zoning permit and a $600 building permit for up to 1,200 square feet, plus $0.30 for each square foot above that. An attached garage adds $90.

In Raleigh, the city's Development Fee Guide for July 2026 through June 2027 sets the building permit at 0.38% of construction value, with electrical, mechanical, plumbing and plan review fees figured as percentages of that. A single-family open space fee runs $1,615 to $1,916 depending on zone.

Septic and well, if your lot has no public water or sewer: Wake County's wastewater fees total $800 for a new septic system's two permits, and a new private well permit is $800, according to the county's well permit page. Johnston County's environmental health fees, effective July 1, 2026, list $600 for a septic permit for systems of 480 gallons or less and $400 for a private well. These are permit fees only; installing the system or drilling the well is a separate cost.

What costs do families forget?

Water and sewer connections. Johnston County Public Utilities' current fee schedule, starting September 1, 2026, lists a $1,000 water tap, an $8,980 water System Development Fee and a $395 meter for a 3/4-inch connection. Sewer adds a $3,890 System Development Fee and a tap fee of the county's cost plus 10%, at least $1,250. In Raleigh, capital facility fees for a 3/4-inch meter are $2,171 for water and $3,335 for sewer, and when the city installs the connections, a water tap is $5,756 and a sewer tap $5,155.

Changes and failed inspections. Wake charges $100 to $400 for re-inspections and $60 to amend a permit, such as when the number of bedrooms changes. Johnston charges $250 for plan changes after approval.

Items with no public price. Get written quotes for:

• Clearing and grading
• The driveway
• Septic installation
• Well drilling
• Land, property tax and loan costs, which a real estate attorney or lender can walk you through