Due diligence when buying land is the investigation you run between signing the purchase agreement and closing, and it exists because vacant parcels hide their problems in places you cannot see from the road: public records, soil, and rights that may have been separated from the surface decades ago. The typical window is 30 to 90 days, negotiated into the contract. Use it to verify who owns what, whether you can legally build what you plan to build, whether the land can physically support it, and what liabilities and costs come with the deed. Miss any one of those, and a promising parcel becomes an expensive mistake.
Keep Your Earnest Money in Play
Before you spend a dollar on inspections, look at the contract. A due diligence contingency clause lets you terminate and recover your earnest money if the investigations turn up problems you will not accept. Without it, walking away means forfeiting the deposit, and on a land deal the deposit is often substantial.
For vacant land, common contingencies cover a satisfactory title search, a survey, environmental testing, a percolation test, zoning confirmation, and confirmation of legal access. Each needs a clear deadline. Environmental testing in particular often runs longer than expected, so build in a right to extend. Once the diligence period expires, you are generally locked in or you lose the deposit.
Verify Who Owns What, and Where the Lines Run
Title Search and Title Insurance
A title search traces ownership through public records and surfaces the encumbrances that come with the parcel: unpaid contractor liens, delinquent property taxes, recorded easements, and gaps or fraudulent transfers in the chain of title. Parcels that have sat unused for years tend to accumulate recording errors and boundary disputes, so problems show up on vacant land more often than buyers expect.
An owner’s title insurance policy protects you against losses from defects the search missed. It is separate from the lender’s policy, which only covers the mortgage company. For a one-time premium paid at closing — usually a fraction of a percent of the purchase price — the owner’s policy covers legal defense and financial losses if someone later asserts a valid claim against your ownership.
Survey the Property, and Look at the Edges
A standard boundary survey locates property lines and corner markers. For vacant land, an ALTA/NSPS Land Title Survey is worth the extra cost because it also locates utilities, easements, and encroachments — information title insurers rely on when deciding whether to remove broad survey exceptions from your policy.1National Society of Professional Surveyors. 2026 ALTA/NSPS Standards A simple boundary survey on a small lot can run a few hundred dollars; a detailed ALTA survey on a larger parcel can run several thousand.
Pay attention to what the survey shows about the neighbors. A fence, driveway, or outbuilding that crosses onto your land is not just an inconvenience. If a neighbor has used part of the parcel openly, exclusively, and continuously for long enough — typically 7 to 20 years depending on the jurisdiction — they may be able to claim ownership of that strip through adverse possession.2Legal Information Institute. Adverse Possession Catching an encroachment now gives you leverage to resolve it before closing.
Confirm What You Can Legally Build
Zoning
Local zoning ordinances control what you can build and how you can use the land. Municipalities divide territory into residential, agricultural, commercial, and industrial zones, each with rules on building height, lot coverage, setbacks, and permitted uses. Call the local planning and zoning department, confirm the classification, and verify your intended use is allowed. If it is not, ask whether a variance or rezoning is realistic before you commit further.
CC&Rs and HOA Rules
Even where zoning allows your plans, private restrictions might not. Covenants, Conditions, and Restrictions are private agreements recorded against the property, most often in planned communities and common interest developments, and they bind every owner.3Legal Information Institute. Covenants, Conditions, and Restrictions They can require minimum home sizes, approved exterior materials, landscaping standards, or bans on structures like metal buildings and detached workshops. Because they run with the land, they bind future owners regardless of consent at purchase. A title company can supply copies. Read them cover to cover.
Permits and Impact Fees
Zoning approval is not a green light to build. Most jurisdictions require building permits, and the application process can involve engineering reviews, site plan approval, and code compliance. On undeveloped land, you may also owe impact fees — one-time charges local governments levy on new development to fund roads, schools, parks, and other infrastructure. These vary widely and can add thousands to a project budget. Ask the local building department about every required permit and fee before closing, because those numbers belong in your purchase-price analysis.
Check Whether the Land Can Physically Support Your Plans
Utilities and Septic
Find out whether the parcel can connect to public water and sewer, or whether you will need a private well and septic system. If public utilities are available, ask about connection fees and capacity. If they are not, drilling a well and installing a septic system becomes a major line item; conventional septic installations often run $3,000 to $12,000 or more depending on soil and system size.
Before a septic system can go in, most jurisdictions require a percolation test to measure how quickly the soil absorbs water. A failing perc test can mean the land simply cannot support a conventional septic system, which ends most residential plans. Alternative systems exist at significantly higher cost. Budget $750 to $1,900 for the test and schedule it early in the diligence period. If the soil fails, nothing else matters.
Do not overlook extending power, internet, and gas to a remote parcel. Utility companies will provide estimates, and the numbers can be staggering. A quarter-mile power line extension alone can cost tens of thousands of dollars.
Legal Access
A dirt road leading to the parcel is not the same as a legal right to use it. Physical access and legal access are two different things, and this trips up more buyers than almost any other issue. If the only route to your land crosses someone else’s property, you need a recorded easement granting permanent access. Without one, the parcel is functionally landlocked, and a neighbor who tolerates your use today can block it tomorrow.
If the parcel was carved out of a larger tract and left without road frontage, you may have grounds for an implied easement by necessity, but establishing one in court is expensive and uncertain.4Legal Information Institute. Implied Easement by Necessity The better path is to confirm recorded legal access during diligence and make it a contingency of the purchase.
Screen for Environmental and Regulatory Exposure
Flood Zones
Check whether any part of the property sits in a Special Flood Hazard Area by pulling the Flood Insurance Rate Maps through FEMA’s Flood Map Service Center.5Federal Emergency Management Agency. Flood Maps Building in a flood zone does not automatically kill a project, but it changes the economics. Construction must meet elevated foundation standards, and a federally backed loan will require flood insurance as a permanent carrying cost.6Federal Emergency Management Agency. Understanding Flood Risk: Real Estate, Lending or Insurance
Wetlands
Wetlands can severely limit where and whether you can build. Filling or grading wetlands under federal jurisdiction requires a Section 404 permit from the Army Corps of Engineers, and the process often demands compensatory mitigation elsewhere.7U.S. Environmental Protection Agency. Section 404 of the Clean Water Act: Permitting Discharges of Dredge or Fill Material The scope of federal protection narrowed after the Supreme Court’s 2023 decision in Sackett v. EPA, which held that only wetlands with a continuous surface connection to traditionally navigable waters qualify under the Clean Water Act.8Supreme Court of the United States. Sackett v. EPA – Supreme Court Opinion The agencies amended their rules to conform,9U.S. Environmental Protection Agency. To Conform with Recent Supreme Court Decision, EPA and Army Amend Waters of the United States Rule and as of late 2025 have proposed a further updated definition.10U.S. Environmental Protection Agency. Definition of Waters of the United States: Rule Status and Litigation Update Wetlands that no longer qualify federally may still be regulated at the state or local level. If the property has any wet or marshy areas, hire a qualified consultant to do a wetlands delineation before closing.
Contamination and the Phase I ESA
This is where the stakes get genuinely dangerous. Under the federal Superfund law, the current owner of contaminated property can be held liable for the full cleanup cost even if someone else caused the contamination decades earlier.11Office of the Law Revision Counsel. 42 USC 9607 – Liability Liability is strict. Cleanup costs routinely reach six or seven figures, and the liability follows the title.
The primary defense is qualifying as an “innocent landowner” who conducted “all appropriate inquiries” into the property’s history before purchasing.12Office of the Law Revision Counsel. 42 USC 9601 – Definitions In practice, that means hiring an environmental professional to perform a Phase I Environmental Site Assessment meeting the ASTM E1527-21 standard, which the EPA has recognized as satisfying the requirement.13Federal Register. Standards and Practices for All Appropriate Inquiries
A Phase I does not involve drilling or sampling. The consultant reviews historical records, aerial photographs, government databases of known contaminated sites, and the chain of ownership, inspects the site, and interviews past owners or occupants. The goal is to flag “recognized environmental conditions.” If any turn up, a Phase II follows with soil and groundwater sampling. To preserve the liability protection, buyers must also take reasonable steps to address any contamination they discover and prevent further releases.14U.S. Environmental Protection Agency. Third Party Defenses/Innocent Landowners Skipping the Phase I to save a few thousand dollars is one of the worst gambles in real estate.
Protected Species
The Endangered Species Act makes it unlawful to “take” any listed species, and courts have read “take” broadly enough to reach habitat destruction.15Office of the Law Revision Counsel. 16 USC 1538 – Prohibited Acts If your land contains habitat for a listed species, clearing it could trigger federal enforcement. The workaround is a Section 10 incidental take permit, which requires a habitat conservation plan detailing impact, mitigation, alternatives, and funding.16U.S. Fish and Wildlife Service. Section 10 – Exceptions The process can take months to over a year and may require mitigation credits or setting aside part of the property. For a buyer who just wants to build a house, that finding changes the whole calculus.
Look Below the Surface and at the Water
Mineral Rights
Buying land does not necessarily mean buying what lies beneath it. In many parts of the country, mineral rights have been severed from the surface estate through a deed, reservation, or federal patent, sometimes generations ago. When ownership is split, the mineral estate is typically considered dominant, meaning the mineral owner or their lessee has the right to access the surface to the extent reasonably necessary to extract those minerals.
Someone else, in other words, could have the right to drill, mine, or excavate on property you thought you owned outright. A thorough title search should reveal any severance in the chain of title, and your title policy should address it. In roughly a dozen states, dormant mineral statutes allow unused mineral interests to revert to the surface owner after a period of inactivity — typically 10 to 20 years — if the holder fails to file a preservation notice. Whether any such statute helps depends entirely on the state.
Water Rights
In the western half of the country, water is allocated under prior appropriation: first in time, first in right. Water rights are property separate from the land, and they do not necessarily transfer with a deed. A senior holder gets their full allocation before junior holders receive anything. If you are buying land for agriculture, livestock, or anything else that depends on reliable water, verify which rights attach to the property, whether they are in good standing, and whether they will transfer at closing. Forfeiture for non-use is a real risk in many western states, where rights can lapse after as few as five years of inactivity.
In the eastern half of the country, water is generally governed by riparian rights: if your land borders a water source, you have a reasonable right to use it. The rules are less formal but still worth investigating if your plans depend on water access.
Understand Every Cost That Will Follow You
Property Taxes and Reassessment
The most significant recurring cost is property taxes. Contact the local assessor, confirm the current rate, review the assessment history, and ask about any planned reassessments. A change in ownership frequently triggers a reassessment to current market value, especially when the seller owned the parcel for many years and benefited from caps on annual increases. The first tax bill after closing often bears no resemblance to the figures shown during diligence.
Special Assessments
Special assessments are charges levied on properties within a specific district to fund infrastructure improvements such as roads, water lines, or sewer systems. They are not the same as regular property taxes; they are tied to a project and billed only to properties that directly benefit.17Federal Highway Administration. Center for Innovative Finance Support Fact Sheets – Special Assessments An existing assessment could mean the seller is passing along a debt you did not budget for. A planned one could mean a bill lands shortly after closing. The local assessor’s or public works office can tell you what is current and what is coming.