Land looks like a simpler purchase than a house. There is no roof to fail, no inspection report, no kitchen anyone dislikes. In practice it is the harder transaction, because everything that makes a house habitable is a question rather than a given.
Access, before anything else
Start here, because a parcel with no legal access is close to worthless regardless of how good the views are.
Being able to drive to a property is not the same as having a recorded right to. Rural access frequently runs across someone else's land, and if that arrangement rests on a handshake or on thirty years of habit rather than a recorded easement, it does not reliably transfer to you.
Ask specifically: is access recorded, does it run with the land, is it wide enough for construction traffic and emergency vehicles, and who maintains it. A shared private road with no maintenance agreement is a future dispute waiting for a bad winter.
Water
The second question, and on Hill Country land often the deciding one. Is there a well, and if so what does it actually produce under a sustained test. Is there a shared or community system, and what does it cost. Is rainwater collection viable given the roof area you plan and the storage you can install.
If there is no well, the question is whether one can be drilled, what the groundwater conservation district permits, and what neighbours experienced in the last dry year. That last question is worth more than any brochure. See wells and rainwater collection outside Austin.
Soil, and whether a septic system will work
Outside municipal service, wastewater is handled on site, and that requires soil that will take it. Thin soil over limestone, which describes a great deal of this region, constrains what is possible and may force a more expensive aerobic system.
Have the soil evaluated before you buy rather than after you have paid an architect. A lot that cannot support a system for the house you intend is a lot that does not do what you bought it for. See septic vs city sewer outside Austin.
What conveys, and what does not
Texas allows the surface and mineral estates to be severed, and on a great deal of Texas land they were separated generations ago. If the minerals belong to someone else, the mineral estate is generally dominant, which can include rights of reasonable surface access.
On a suburban lot this is usually academic. On acreage it is not, and it belongs in your diligence rather than in the fine print you read afterwards. Water rights, existing leases, and any agricultural or hunting lease in place are worth the same question: what exactly am I buying.
Restrictions
Land is rarely unrestricted. Deed restrictions, subdivision covenants, conservation easements, and county rules can all limit what you build, how many structures you put up, whether you can operate a business, whether short-term letting is permitted, and sometimes minimum or maximum house sizes.
Read the restrictions before you fall for a parcel, not after. A conservation easement in particular is permanent and travels with the land.
Over the Edwards Aquifer recharge zone, which covers much of the ground west and southwest of Austin, additional environmental requirements apply to development. That is not a reason to avoid it and it is a real constraint on cost and design.
Utilities cost what they cost
Ask what it costs to bring power to the building site, and get a written estimate from the provider rather than an assurance from a seller. Distance from an existing line drives that number, and on a large parcel the difference between two potential building sites can be substantial.
Then internet, which matters more than people admit for anyone working from home. Availability varies enormously in this region. Check the specific address rather than the general area.
Financing and taxes work differently
Raw land loans generally require a larger down payment, carry higher rates, and run shorter terms than a residential mortgage. Plan financing before you shop rather than after you have found a parcel.
On the tax side, land carrying an agricultural or wildlife valuation is taxed on its productive use rather than market value, which is a large difference. That valuation is not automatic and it can be lost, triggering a rollback of back taxes, if the use changes after you buy.
Where this comes up
Around Dripping Springs, Spicewood, Wimberley, Liberty Hill, and the land above Lakeway. Some of the best country in Texas, and none of it forgiving of a buyer who skipped the questions above.
What we do about it
We work through access, water, soil, restrictions, utilities, and what conveys before you are committed, and we would rather find the problem that kills a parcel during the option period than after you own it. Land rewards patience in a way houses do not.