If you build your own house, you don’t pay income tax on the value you create by building it, but you will owe sales and use tax on the materials, property tax that rises sharply once the home is finished, and potentially capital gains tax if you later sell for a profit. A few federal deductions can soften the cost while construction is underway, and the rules for paying workers are more forgiving on a personal residence than most people assume. Here is what to plan for at each stage when you take on the taxes that come with building your own house.
Sales and Use Tax on Building Materials
Most states charge sales tax on building supplies, and as the person who will ultimately use those materials, you are the end consumer. The tax applies at the register on lumber, concrete, fixtures, wiring, and everything else that goes into the structure. If you hire a general contractor, the same logic applies. The contractor buying on your behalf is still purchasing for the final consumer, and sales tax is owed on the materials.
The less obvious obligation is use tax. When you order materials from an out-of-state supplier that doesn’t collect your state’s sales tax, you owe the equivalent amount directly to your state’s revenue department. Use tax exists to prevent people from dodging sales tax by shopping across state lines, and it applies at the same rate. States expect you to self-report these purchases on your state return, and some localities require an estimated use-tax deposit before issuing a building permit, with a final reconciliation after construction wraps up.
Keep every materials receipt. Those receipts handle tax compliance and also establish your cost basis, the number that directly reduces your taxable gain if you ever sell.
Property Taxes Before and After the Home Is Finished
While construction is underway, your property tax bill is based on the value of the land alone. Depending on where you’re building, that can mean a noticeably lower bill for 12 to 24 months.
Once the home is finished and a certificate of occupancy is issued, the local assessor is notified that a new structure exists. The assessor adds the value of the completed home to the land value, and that becomes the property’s new taxable value. Assessors typically look at your construction costs (building permits provide a starting point), comparable home values in the area, and features like square footage and material quality.
The reassessment doesn’t always wait for the next annual tax cycle. Many jurisdictions issue a supplemental tax bill covering the gap between when construction finishes and the next regular assessment date. The supplemental amount is prorated based on the time remaining in the tax year, so you pay the higher rate only for that remaining portion. This bill catches people off guard because it arrives separately from the regular property tax notice and often within a few months of moving in.
Federal Deductions You Can Claim During Construction
Two federal deductions can offset some of the financial burden while you build. Both require itemizing on your return rather than taking the standard deduction.
Construction Loan Interest
If you’re financing the build with a construction loan, the IRS lets you treat a home under construction as a qualified home for up to 24 months, as long as it becomes your main home or second home once it’s ready for occupancy.1Internal Revenue Service. Real Estate (Taxes, Mortgage Interest, Points, Other Property Expenses) The 24-month window starts on or after the day physical construction begins. Clearing, grading, excavating, or actual building work all count. Interest paid before construction starts, such as during land acquisition, planning, or permitting, does not qualify.
The deduction is subject to the $750,000 acquisition debt limit ($375,000 if married filing separately). This cap applies to the combined mortgage debt on your primary home and any second home, so if you already carry a mortgage on another property, the remaining room under the limit may be smaller than you expect. The loan must also be secured by the property being constructed.
State Sales Tax Deduction
When you itemize, you choose between deducting state and local income tax or state and local general sales tax, not both. In a year when you’re spending heavily on taxable building materials, the sales tax deduction could easily surpass your state income tax. The IRS provides optional sales tax tables based on income, and if your construction materials were taxed at the general sales tax rate, the sales tax paid on those materials can be added on top of the table amount.
Either way, this deduction falls under the SALT (state and local tax) cap, which for 2026 is $40,400 ($20,200 for married filing separately). The cap begins to shrink once your modified adjusted gross income exceeds $500,000, reduced by 30 cents for every dollar over that threshold, down to a floor of $10,000. For many owner-builders, property taxes and sales tax together will bump against this limit well before they’ve captured the full benefit.
Capital Gains Tax If You Sell
If you eventually sell the home for more than you spent building it, the profit is subject to capital gains tax. Your cost basis, the number subtracted from the sale price to calculate the taxable gain, includes the price of the land plus your total construction costs.
IRS Publication 551 lists the expenses that count toward the basis of a self-built home:2Internal Revenue Service. Publication 551 – Basis of Assets
- The purchase price of the land
- Labor and materials, from framing lumber to drywall installation
- Architect’s fees for design and engineering
- Building permit charges paid to your local jurisdiction
- Payments to contractors, including electricians, plumbers, and roofers
- Rental equipment such as excavators and scaffolding
- Required inspection fees during construction
One thing does not count: the value of your own labor. The IRS is explicit that you cannot include sweat equity, or any other labor you didn’t pay for, in the basis of property you construct.2Internal Revenue Service. Publication 551 – Basis of Assets If you spent weekends framing walls or laying tile, that time doesn’t increase your cost basis. Only money you actually spent is counted. The more work you do yourself, the lower your basis and the larger your taxable gain on a future sale.
The Section 121 exclusion can wipe out that tax entirely for many owner-builders. An individual can exclude up to $250,000 of gain from the sale of a primary residence, and married couples filing jointly can exclude up to $500,000. To qualify, you need to have owned the home and used it as your principal residence for at least two of the five years before the sale, and the two years don’t need to be consecutive.3Office of the Law Revision Counsel. 26 U.S. Code 121 – Exclusion of Gain From Sale of Principal Residence For someone who built the home and lived in it for several years, this exclusion frequently covers the entire profit.
Paying the People Who Help You Build
If you’re building a home to live in, you are not operating a trade or business. You’re undertaking a personal project. That distinction matters because the IRS requires Form 1099-NEC reporting only for payments made in the course of a trade or business; personal payments are not reportable.4Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC So when you hire a plumber, electrician, or roofer to work on your personal residence, you generally don’t need to file a 1099-NEC for those payments.
The rules change if you’re building to sell or constructing a rental property. That activity qualifies as a trade or business, which triggers 1099-NEC requirements for each contractor paid $2,000 or more in a calendar year, a threshold that increased from $600 for payments made after December 31, 2025.5Internal Revenue Service. 2026 Publication 1099
The one area where even personal-residence builders can face payroll obligations is the employee-versus-contractor distinction. If you hire someone directly and control not just what gets done but how and when they do it, the IRS may treat that person as your employee. In that case, you’d owe employment taxes including Social Security and Medicare contributions. For 2026, household employer obligations kick in when you pay a single worker $3,000 or more in cash wages during the year.6Internal Revenue Service. Publication 926 – Household Employer’s Tax Guide In practice, this is uncommon for owner-builders. Most hire licensed subcontractors who bring their own tools, set their own schedules, and carry their own insurance. The risk appears when someone hires day laborers or unskilled helpers and directly supervises every aspect of their work.
Energy Tax Credits Are Mostly Gone for New Builds
If you were counting on a federal tax credit for solar panels or other clean energy systems installed during construction, the ground has shifted. The Residential Clean Energy Credit under Section 25D, which covered 30% of installation costs for solar, wind, geothermal, and battery storage systems, does not apply to property placed in service after December 31, 2025.7Office of the Law Revision Counsel. 26 U.S. Code 25D – Residential Clean Energy Credit For homes completed in 2026 or later, this credit is no longer available.
The Section 45L credit for energy-efficient new homes still exists through mid-2026, but it’s designed for eligible contractors who build homes for sale, not for individuals constructing their own residence.8Internal Revenue Service. Credit for Builders of New Energy-Efficient Homes State and local incentives for energy-efficient construction may still be available and vary widely by jurisdiction, so checking with your state energy office before finalizing plans is worth the effort.