What a barndominium costs to build in Delaware and Maryland

Shell or finished: the first decision

The first thing that sets the price is how far the builder takes the house. A shell is the structure: posts, trusses, roof, walls, exterior doors and windows, and often the slab. A finished home adds everything inside: insulation, plumbing, wiring, heating and cooling, drywall, kitchen, baths, flooring and trim. Once the first set of drawings is done, we quote either one, just the shell or the complete fit-out from start to finish.

A shell price looks smaller, but the house still has to be finished and pass inspection before anyone lives in it. If you finish it yourself or hire your own trades, you take on the scheduling, the subcontractors and the inspections, and the home still needs the county’s final inspection and a certificate of occupancy. If you’re financing, talk with your lender before you choose, because the loan has to cover whatever the builder doesn’t.

The slab and the ground under it

Most barndominiums sit on a concrete slab, and a house slab does more than a shop floor. Drains and water lines go in before the pour, so the floor plan has to be final first. Living space usually gets a vapor barrier under the concrete and insulation planned at the slab edge, and some owners add tubing for radiant floor heat. Garage and shop areas may need a thicker slab where a lift or heavy machine will sit.

The site matters as much. Low spots need fill brought in and compacted, and in a mapped flood zone the flood rules set the floor height: in Sussex County the lowest floor must be at or above the base flood elevation, and New Castle County requires 18 inches of freeboard and prohibits net fill in the floodplain. Building higher to meet those rules is a real cost, so check the flood map before you settle on a spot for the house.

Septic and well

On rural land without public sewer and water, the septic system and well are costs a town lot doesn’t have, and the soil decides what kind of septic system you can use. In Delaware, an off-sewer home needs DNREC approval in three steps: a site evaluation by a licensed Class D soil scientist, a design and permit from a licensed Class B designer for a gravity system or a Class C designer for an engineered or pressure-dosed one, and installation by a licensed Class E contractor.

Engineered and pressure-dosed systems are more involved than gravity systems, which is why the soil evaluation comes early. A well must be drilled by a DNREC-licensed water well contractor, who files the well permit application, and a proposed well with a potential contamination source within 1,000 feet gets a contamination review. Sussex County wants the DNREC septic completion report before its final inspection.

In Maryland, well and septic approvals run through the county health department. The Somerset County Health Department’s Environmental Health program reviews private septic systems and wells and does perc tests (443-523-1700), and in Queen Anne’s County the Health Department’s Environmental Health Section signs off on well and septic (410-758-1271). Plan the septic area first; it can decide where the house goes.

Permits, drawings and inspections

A barndominium is a house, so it’s drawn to the residential code and permitted like one, and homes usually take 3 to 5 months to permit, depending on the county. For homes, the drawings come from a house designer who specializes in post-frame design, one we work with regularly. Once the contract is signed, we manage the permits, unless you’d rather handle them yourself.

The paperwork reaches past the fee. In Sussex County, a pole building with approved living space must meet single-family dwelling requirements, and poles over 16 feet or a second story outside the trusses need sealed plans.

Kent County doesn’t require sealed plans for a single-family home, but it can require approvals from the State Fire Marshal, the Kent Conservation District, the Division of Public Health, DNREC and a Delaware-recognized electrical inspection agency before the permit, plus a DelDOT entrance permit on a state road. Delaware also requires a sediment and erosion control plan for disturbing 5,000 square feet or more, and that includes a single-family home site.

In Maryland, every county builds to the same Maryland Building Performance Standards, currently the 2021 IRC, and counties may not weaken the residential sprinkler provisions. New one- and two-family homes, barndominiums included, keep the sprinkler requirement, with narrow exceptions such as a property not connected to an electric utility, and on a well the water supply has to be planned for it. Our guide to living in a pole barn covers zoning and the legal side.

The energy code

Energy rules shape the walls, roof, windows and mechanical systems of every new home, and Delaware’s are changing. State law makes county and town codes meet the most recent IECC within 12 months of the Delaware Energy Office adopting it, and as of December 31, 2025, all new residential construction must be “zero net energy capable.” In April 2026, DNREC’s State Energy Office adopted the latest IECC with zero-net-energy-capable amendments.

Sussex County will enforce the 2024 IECC from April 11, 2027 for new homes and for conditioned residential additions and accessory structures, and plans submitted after April 10, 2026 must be designed to the 2024 IECC with a REScheck or COMcheck report. Kent County’s adopted-codes page lists the 2018 IECC, which may change after the state’s 2026 update. Maryland uses the 2021 IECC statewide, with the 2024 edition proposed, and counties can make the energy code stricter but not weaker. Confirm the edition with the building office before the drawings are final.

For cost, that means thicker insulation, better windows, careful air sealing, right-sized heating and cooling and the energy report itself. Post-frame walls are deep, which leaves room for thick insulation. If the shop or garage under the same roof stays unheated, the wall between it and the house becomes part of the insulated envelope.

Interior allowances and finishes

Allowances are a common reason two finished-home quotes look alike but aren’t. An allowance is a placeholder budget for something you haven’t picked yet: cabinets, countertops, flooring, plumbing fixtures, lighting or appliances. If your picks cost more than the allowance, the price goes up, so a quote with low allowances looks cheaper than the house you actually want. Compare allowances line by line, and set them close to what you expect to choose.

The other interior choices that move the price shape the space itself: a vaulted ceiling on scissor trusses, a loft or second floor, a fireplace and chimney, and drywall or steel liner on the walls. Every bathroom adds plumbing, fixtures and finish, so a plan with more baths costs more than one the same size with fewer.

Garage, shop space and porches

Room for a shop or garage under the same roof is one of the reasons people build barndominiums, and that space is priced differently from living space. A garage bay or shop needs a slab, overhead doors and lighting, but not a kitchen, baths or full interior finish. Heat or cool it and it becomes part of the home’s conditioned space under the energy code. An attached garage also has to meet the residential code’s garage rules, including how it’s separated from the living space.

Porches are the other big exterior choice. A wide covered porch or a timber-framed gable gives a post-frame home its front, and each one adds posts, framing, roofing, a ceiling and often concrete; a wraparound porch multiplies that. Decide on porches and lean-tos before the drawings are done, since they reshape the roofline and where the house sits on the lot. Our pole barn cost guide covers the shell choices in more detail.

Comparing quotes and paying for it

Ask each builder to price the same scope: shell or finished, the same plan and slab, the same septic and well, the same allowances, site work, driveway and permits. Then compare what’s left out, because a lower number that skips the septic system, or the sprinklers in Maryland, isn’t a lower price. Our quote is organized and easy to read, and the contract lists the payment schedule. The final payment is due once the build is complete and the county’s final inspection is done; the certificate of occupancy follows.

Most people pay for a new home with a construction loan or mortgage from a bank or credit union, and the lender will want the drawings and contract, which we provide. For smaller projects, such as a shop added later, our partner HFS Financial offers home-improvement loans with no home equity needed; see financing. Browse our barndominiums and Maryland barndominiums pages for photos and planning advice, then ask for a free quote on yours.