Barndominium cost calculator for the Texas Hill Country

Compass Camper LLC is a marketing and matching service, not a contractor. This page prices nothing itself. It restates ranges other people published, keeps them as ranges, and names each one. The cost guide explains why a single confident dollar figure would not be honest here, and this page holds to that: it never collapses the spread into one number. Only a licensed local builder, standing on your site with your plans, can quote your project.

Estimate your build

Everything this widget does is already on the page as a table. It only saves you the arithmetic.

Finished square footage

30x40 30x50 40x60 40x80 50x80 60x80

This calculator covers 400 to 12,000 sq ft.

Scope

Finished turnkey Shell only (frame, roof, walls, slab)

No publisher prices a separate dried-in tier, so dried-in is not offered as its own option.

Site work add-ons

Aerobic septic system (ATU), plus site evaluation and system design ($11,100 to $25,000) Water well, drilled and equipped ($10,000 to $45,000) Limestone site work: clearing, grading, rock removal, drainage, driveway ($20,000 to $80,000) Engineered, sealed structural plans ($1,450 to $5,500) Electric service, published cooperative fees only ($575 to $875)

Planning estimate, three layers kept separate. As shown: 2,400 sq ft, finished turnkey, five site work add-ons.

Shell	$120,000 to $192,000
Interior finish	$240,000 to $648,000
Site work	$43,000 to $156,000
Total	$403,000 to $996,000

The building is the predictable part. The site is the variable part. A shell of a given size costs about the same on any lot, while the septic, the well, the rock, and the driveway depend on your specific acre and do not scale with building size. Estimate only, assembled from the published ranges below and verified as of July 27, 2026. Land, the electric line extension, and Edwards Aquifer review are not included.

Common Hill Country sizes, precomputed

Shell and finished figures are the published per-square-foot bands multiplied by floor area and rounded to the nearest thousand. The site-work column is the same dollars in every row on purpose: those costs come from the land, not from the size of the building.

Shell band $50 to $80 per square foot (Texas Complete Barndo Solutions, Published 2026-04-17). Finished band $150 to $350 per square foot, the union of Quality Hill Country Homes at $150 to $280 and J. Bryant Boyd at $200 to $350 and up. Every figure is restated in the methodology table below with its source and date.

Site work add-ons, one row per sourced item

These are the Hill Country lines a national calculator never shows. Each one is priced from a published figure or a disclosed sum of published figures. Nothing here is estimated by us. These rows print the exact published dollars, so they read a few hundred off the calculator and the sizes table above, which round to the nearest thousand. The publisher and the date behind every figure in this table are listed in the methodology table below.

Septic: the permit line, and when it does not apply

The septic row above covers the system, the site evaluation, and the design. The county permit is extra. Gillespie County publishes its fees: $325 for a new or upgraded system under 500 gallons per day, and $425 where a maintenance contract is required, which is the case for an aerobic unit (Gillespie County fee schedule, Effective 2025-10-14). Across Texas, county permit fees run $30 to $710 depending on the county and the system type (Texas Septic Guide, permit lookup, Updated and verified by the publisher 2026-03-09). Where TCEQ administers the program directly the statutory fee is $200 for a single-family dwelling plus a $10 state surcharge, a floor almost nobody in this area actually pays because every county here is an authorized agent charging its own fee (30 TAC 285.21, Last amended 2012-08-16, verified as of July 27, 2026).

On a tract of 10 or more acres the permit and planning step can be exempt under 30 TAC 285.3, which would remove the permit and the design fee, but all five conditions have to hold: the tract is 10 acres or larger, the single-family dwelling is the only dwelling on the tract, every part of the system sits at least 100 feet from all property lines, effluent stays on the same tract, and the system is not causing a nuisance or polluting groundwater. On thin soil over limestone that last condition is the one that fails. Gillespie County requires an approved system in all areas regardless of tract size (Gillespie County OSSF order, Effective 2025-10-14), and other counties are tightening their rules, so confirm with your county before you count on the exemption. The septic and OSSF guide walks through it, and the Gillespie County page has the local office.

An aerobic unit costs money every year, not just once

The required maintenance contract runs $200 to $500 a year, and all in, including electricity, amortized pumping, and disinfection, an aerobic unit runs $500 to $800 a year to keep (Texas Septic Guide, Verified by the publisher 2026-03-09). That is an ongoing cost, so it is not in the estimate above, which prices the build.

How this estimate is built

Every band, its publisher, its date, and what kind of figure it is. The distinction matters: survey data is measured, contractor-published figures are marketing. Treat the contractor bands as the shape of the market rather than a quote.

Three things worth knowing about these numbers

First, no government agency or established survey publisher breaks barndominiums out as a category. Not the Census Bureau, not NAHB, not the state extension service. Every per-square-foot barndominium figure on this page is contractor-published or supplier-published marketing, and the page labels it that way. The only survey-grade rail available covers custom homes generally, and it sits well below the barndominium bands at a $138 median per square foot for the West South Central division.

Second, the Hill Country bands sit above the statewide bands, and that gap is real rather than noise. The two statewide publishers do not agree with each other: Texas Complete Barndo Solutions puts turnkey at $160 to $180 per square foot and Squires Construction puts it at $140 to $150. Those are two disjoint bands, and nobody publishes anything between $150 and $160, so this page does not merge them into one continuous $140 to $180 range. The Hill Country publishers sit above both, at $150 to $280 and at $200 to $350 and up. Limestone, slope, distance from suppliers, and the finish level buyers here choose all push it. This page drives off the Hill Country figures and shows the two statewide bands as low anchors rather than averaging anything into a number nobody published.

Third, the interior finish line is derived, not published. It is the finished band minus the shell band, so shell plus interior always equals the finished total. Against the statewide turnkey bands the shell works out to roughly a third to a half of a finished build, and the arithmetic is worth showing because the two statewide publishers disagree. Against the $160 to $180 band the $50 to $80 shell is 28 to 50 percent ($50 divided by $180, then $80 divided by $160). Against the $140 to $150 band it is 33 to 57 percent ($50 divided by $150, then $80 divided by $140). Against the higher Hill Country finished bands the shell is a smaller share, because the extra Hill Country money lands in finish and siting, not in the steel.

What this estimate leaves out on purpose

A calculator that invents a number for an unpublishable cost is worse than one that names the gap. Four costs are deliberately excluded because no one publishes a figure for them.

• The electric line extension. Neither Central Texas Electric Co-Op nor Pedernales Electric Cooperative publishes a per-foot or per-mile rate. Both compute the contribution in aid of construction case by case from an engineered estimate. Only the fixed application and engineering fees above are published, and only those are in the estimate.
• The ridge-top wind premium. An exposed crest raises effective wind pressure through the ASCE 7 topographic factor, and no source prices that increment separately from the plan set. Pull your own design wind speed for your exact address from the ASCE Hazard Tool, and read the wind-load guide for what to ask a builder for.
• Water storage and booster pumps. Common on low-yield Hill Country wells, with no published Texas figure found.
• Edwards Aquifer review. Hays and Comal counties sit over the regulated recharge and contributing zones, and so does the southeast corner of Kendall County near Boerne. A Water Pollution Abatement Plan or Contributing Zone Plan adds time and cost that TCEQ does not publish a price for. The five western counties are outside the program.

Land is also excluded, which matters more than it sounds: the custom-home survey figures above exclude the improved lot too, because custom homes get built on ground the owner already owns.

How to use this before you talk to a builder

Take the three lines separately. Argue with the finish line, because that is the one you control. Then walk the site-work line with someone who has read your actual acre, because that is the one that moves most and the one a national calculator hides. The land feasibility checklist is the order to run those checks in, and the barndominium builders page is where to start when you want the estimate replaced with a real quote.