A finished barndominium at dusk with warm interior lighting glowing through its large windows.
Washington County 2018 IRC with Tennessee amendments

Barndominium Builders in Washington County, TN

This is Washington County in East Tennessee — county seat Jonesborough, Tennessee's oldest town, and largest city Johnson City, the anchor of the Tri-Cities. It is one of the very few Tennessee jurisdictions that answers the barndominium question in writing on its own website: barn-dominium style dwellings are allowed anywhere a single-family home is allowed, and stamped drawings from a design professional are required because the county classes them as an alternative construction method. The county enforces the 2018 International Residential Code itself, its own building inspector runs the footer-to-certificate-of-occupancy sequence in the unincorporated area, and its residential permit form has a checkbox for post-frame construction.

Washington County at a glance

County
Washington County
Population
141,199
ZIP codes
37601, 37604, 37614, 37615, 37659, 37656, 37681, 37690
Site visits
About 300 miles east of our Franklin office, in the Tri-Cities
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Building conditions in Washington County

What actually changes from one Tennessee jurisdiction to the next: who issues the permit, whether the residential code is enforced there at all, what the structure has to be engineered to, and what the ground is like. These are the numbers your drawings have to satisfy.

Build conditions for Washington County , Tennessee: design wind speed Set with the county building official. BUILD CONDITIONS WASHINGTON COUNTY, TNEast TennesseeCRITERIA SET LOCALLY DESIGN WIND SPEED Set with the county building officialWashington County publishes no filled-in Table R301.2, so the ultimate design wind speed, exposure…ZONING · A-1 GENERAL AGRICULTUREOne acre without public water or…A-1 permits detached single-family dwellings outright and places no…BUILDING PERMIT FEE$595 plus $3 per $1,000 above $100,000…Washington County's published schedule is valuation-based on materials…WHO ISSUES THE PERMITWashington County Zoning Office100 E Main Street, Suite 103, Jonesborough, TN 37659, (423) 753-1753…Design criteria are filled in by the jurisdiction under Table R301.2 and are confirmed per parcel before any drawing is sealed.
Build conditions for Washington County, drawn from the sourced facts on this page. Every figure above is cited in the quick-facts panel below, with its source and vintage.
The county answers the barndominium question by name
Washington County's own Frequently Asked Questions page asks "Are barn-dominium style dwellings allowed in Washington County?" and answers: "Yes - Anywhere single family dwellings are allowed. Stamped drawings from a design professional are required for all alternative construction methods." Two questions earlier the same page says plans are not required for a typical residential permit. So the county draws the line explicitly — a conventional house needs no plan set, a barndominium needs a sealed set. That is 2018 IRC R301.1.3, engineered design, restated in plain English on a county web page.

Washington County, TN Zoning, Planning & Building Codes, Frequently Asked Questions, washingtoncountytn.org/377/Frequently-Asked-Questions, fetched 31 August 2026

Building code enforcement
Washington County enforces its own code. The Codes Compliance page states that the county "has adopted and is enforcing the 2018 International Residential Code", and lists the inspections performed by the County Building Inspector: footer, slab where applicable, framing, rough-in plumbing, rough-in mechanical, insulation, plumbing, mechanical, final and Certificate of Occupancy. The Certificate of Occupancy must be obtained before the structure is occupied. The county's permit addendum cites 2018 IRC Section R111.1 and T.C.A. 13-7-110, which confirms the edition a second way.

washingtoncountytn.org/173/Codes-Compliance and the Washington County Building Permit Addendum revised 5 September 2024, DocumentCenter 2203, both fetched 31 August 2026

Post-frame is on the county's own permit form
The Washington County residential building permit application, current revision dated August 2026, carries a Construction Type field with two named options: Conventional and Post frame. The Work Description line adds an Alternative box. A county whose intake form already has a post-frame checkbox is a county whose counter staff have seen the building type before, and it removes an argument most rural jurisdictions still make you have.

Washington County Residential Building Permit Application (8/2026), washingtoncountytn.org DocumentCenter 2880, fetched 31 August 2026

Published design criteria for the Tri-Cities
Washington County publishes no filled-in Table R301.2. Johnson City does, and it is the nearest published set of numbers to the rural county: ground snow load 15 psf, Seismic Design Category B, frost line depth 12 inches, winter design temperature 14 degrees, mean annual temperature 55 degrees, wind speed 90 mph, weathering severe, termite severe-moderate, ice barrier underlayment not required. That sheet governs inside the Johnson City limits. Outside them the figures are settled with the Chief Building Official on (423) 753-2062 before steel is ordered, because a nominal wind speed and an ultimate design wind speed size a frame very differently.

Johnson City, TN Design Criteria, Development Services Department Codes Division, 601 East Main Street, Johnson City, cms7files.revize.com Johnson City Design Criteria PDF, fetched 31 August 2026

No minimum house size, and lot size moves with the utilities
The Washington County Zoning Resolution, re-adopted 28 October 2013 and amended 22 June 2026, sets no minimum heated floor area for a dwelling in any district. In A-1 General Agriculture, where most rural parcels sit, a detached single-family dwelling is a permitted use and the minimum lot area is 15,000 sq ft on public sewer, 21,780 sq ft with public water and a septic system, and one full acre with neither. Lot width is 100 ft at the building line, front and rear yards 30 ft, side yard 12 ft.

Washington County Zoning Resolution Sections 601.1.4 and 601.2, washingtoncountytn.org DocumentCenter 2852, fetched 31 August 2026

The metal siding rule, and who it actually applies to
Section 622, the Corridor Overlay District, requires a Planning Commission waiver for corrugated metal siding, vinyl siding and unpainted concrete block where they are visible from a designated roadway. The overlay runs 300 feet back from the front property line, and any parcel under five acres with any area inside that band is pulled in whole. Section 622.2 then exempts it: "New and existing single-family, two-family, and agricultural uses land uses shall be exempt from the provisions of this overlay." So a metal-skinned house is outside the rule. Converting a residential or agricultural structure to a commercial or industrial use is inside it.

Washington County Zoning Resolution Sections 622.1 to 622.3.3, washingtoncountytn.org DocumentCenter 2588 and the consolidated resolution DocumentCenter 2850, fetched 31 August 2026

Also worth knowing before you build in Washington County

In R-1 the shop cannot outgrow the house
R-1 Low Density Residential caps accessory buildings against the dwelling: "The total floor area of all accessory structures (total square footage) shall not exceed the area within the [principal] structure." A-1 and A-2 carry no equivalent cap, only setbacks — side or rear yard, 12 feet to any lot line. R-1 also requires the owner to sign a statement before the permit is issued affirming the structure is used for residential purposes only and not for commercial or industrial use or storage. On a shouse programme with a large detached workshop, the zoning district decides the build before anything else does.

Washington County Zoning Resolution Sections 604.1.1, 604.1.4 and 604.3, DocumentCenter 2853, and Section 601.1.14, DocumentCenter 2852, fetched 31 August 2026

Three permitting authorities in one county
Washington County's building programme reaches the unincorporated area only. Johnson City runs its own Building Division at 601 East Main Street, (423) 434-6047. Jonesborough, the county seat, runs its own. Watauga is a third municipality. Everything else — Gray, Boones Creek, Limestone, Telford, Fall Branch, Sulphur Springs, Embreeville, Washington College — is county jurisdiction, and the parcel viewer at gis.washingtoncountytn.org/zoningmap settles which side of the line a lot falls on.

washingtoncountytn.org/172/Zoning-Planning-Building-Codes and johnsoncitytn.org Building Division contact details, fetched 31 August 2026

Septic runs through the state, not the county
Washington County does not operate a septic programme under contract. Its own FAQ and its permit form both send applicants to the Tennessee Department of Environment and Conservation on (423) 854-5400, the Johnson City Environmental Field Office, for septic verification, permits and layouts. That matters to sequencing: the county requires the septic permit and the driveway permit in hand before it will issue the building permit, so on an unsewered parcel the soil and site evaluation is at the front of the critical path rather than a later step.

washingtoncountytn.org/377/Frequently-Asked-Questions, the Washington County Residential Building Permit Application, and tn.gov/environment/contacts.html, all fetched 31 August 2026

How the permit actually runs
Inspections must be scheduled by 3:00 p.m. the day before, on (423) 753-1753. One re-inspection is included at no charge; further re-inspections are $40 and must be paid before the next inspection can be booked. The permit becomes invalid if work has not started within 180 days, and expires if no inspection is requested for 180 days. Property corners must be marked and maintained for the term of construction, with the line strung or an as-built survey produced on request. Final inspection also covers driveway, seeding and drainage away from the building, and the owner stays responsible for reseeding until 70 percent growth coverage is reached.

Washington County Building Permit Addendum revised 5 September 2024, DocumentCenter 2203, and the Residential Building Permit Application, DocumentCenter 2880, fetched 31 August 2026

Climate zone 4A, on a 2009-era energy table
Washington County is IECC climate zone 4A under Table N1101.7 of the Tennessee Residential Code 2018. Only twelve Tennessee counties sit in 3A and all of them are in the west of the state. The Tennessee amendments matter as much as the zone: the state replaced Tables N1102.1.2 and N1102.1.4 with the 2009 IRC tables and made duct testing under N1103.3.3 and N1103.3.4 optional, so a 4A envelope specified from a national article is usually specified tighter than Tennessee requires.

Tennessee Residential Code 2018, Table N1101.7, up.codes Tennessee IRC 2018 Chapter 11; Tenn. Comp. R. & Regs. 0780-02-23-.02, fetched 31 August 2026

Which Washington County this is
Tennessee's oldest county, established 1777 while the territory was still part of North Carolina, with Jonesborough — founded 1779, Tennessee's oldest town — as its seat. 326 square miles of land carrying about 141,000 people, which is roughly 410 to the square mile and unusually dense for East Tennessee, so large acreage close to Johnson City is scarce. Buffalo Mountain rises to 3,520 feet at Pinnacle Knob on the eastern boundary. Washington County, Virginia, seat Abingdon, borders Sullivan County immediately to the north, and Bristol straddles the state line between them.

US Census Bureau 2020 census and 2025 county estimate via Wikipedia, Washington County, Tennessee and Jonesborough, Tennessee; Washington County, Virginia adjacency per the same source, fetched 31 August 2026

An excavator grading a compacted building pad on a cleared lot, with survey stakes and a drainage swale visible.
Below the slab

The expensive surprises are in the ground, not the building

What moves a Tennessee budget is usually below grade: limestone sitting shallow, karst voids and sinkholes, and slope. Those are the same conditions that decide whether a septic field passes its soil and site evaluation, so the grading plan, the footing depth and the drainfield get resolved together rather than one at a time. We price the dirt before we price the building.

What we build in Washington County

All nine services are available across Washington County. What a build costs depends far more on the parcel than on square footage, so we price against your land rather than publishing a rate card.

Barndominium Kits

Engineered barndominium shell packages delivered to your Tennessee lot, stamped for the criteria your county adopted.

Turnkey Builds

Start to finish barndominium construction: we handle permits, slab, shell, and full interior finish.

Custom Plans

Barndominium floor plans drawn to your land, your family, and the residential code your county actually enforces.

Post-Frame Homes

Pole barn construction adapted into full residences, with wide clear spans and fast dry-in.

Steel Construction

Red-iron and light-gauge steel framing: no rot, no termites, engineered to your county’s adopted wind criteria.

Shouses

Shop and house in one building: workspace and living space under a single roof and a single permit.

Metal Homes

Full metal-clad residences: low maintenance envelopes specified to your Tennessee climate zone.

Site Preparation

Clearing, grading, pad, drainage, and utilities: the work that decides whether the build goes smoothly.

Permitting & Engineering

Sealed structural engineering and the permit that depends on it, from submittal through final inspection.

What a build looks like

Three stages every Washington County project passes through, from a raw parcel to a finished home. Site work first, because that is where the budget is decided.

Aerial view of an undeveloped rural lot with cleared grass, a cedar and hardwood treeline, and a pale gravel access track.
Stage one

The parcel

Zoning, setbacks, flood zone and utility access get checked before anything is drawn.

An excavator grading a compacted building pad on a cleared lot, with survey stakes and a drainage swale visible.
Stage two

Pad and permit

Clearing, grading and a compacted pad, while the submittal works through Washington County.

A finished barndominium at dusk with warm interior lighting glowing through its large windows.
Stage three

Frame to finish

Shell erected and dried in, then systems, insulation and interior finish through to CO.

Those are the rules for Washington County. Tell us what you want to build and we will draw it to them.

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Where we build around Washington County

Washington County and the rural land around it. The buildable acreage for a project this size usually sits outside the city limits, which is frequently what changes who issues your permit.

Our Washington County service area, covering Washington County and the surrounding rural acreage. We build across this area from our office in Franklin, TN — this map marks the territory we serve, not a branch location.

Keep reading

The questions that usually come next once you know what Washington County allows.

Barndominium Cost Guide

Sourced per-square-foot ranges by tier and by size, with a calculator built on the same figures.

Read it

Is It Legal in Tennessee?

Classification, zoning, the HOA gate, and why "nonresidential farm building" does not cover a home.

Read it

How Long Does It Take?

Census build-duration data, and what actually sets the permit clock where you are building.

Read it

Sources for this page

The primary documents behind the Washington County figures above. We would rather you checked them than took our word for it.

Nearby areas we build in

Others we cover in this part of Tennessee. The permitting authority, the adopted design criteria and the zoning can all differ from one to the next.

Jefferson County

Jefferson County
Knoxville

Knox County

Building in Washington County: common questions

7 questions we get asked most often about building in Washington County. If yours is not on the list, ask it directly.

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Are barndominiums allowed in Washington County, Tennessee?
Yes, and the county says so in writing. Its Frequently Asked Questions page asks whether barn-dominium style dwellings are allowed and answers that they are, anywhere a single-family home is allowed, adding that stamped drawings from a design professional are required for all alternative construction methods. That second sentence is the important one. The same page says plans are not required for a typical residential permit, so the county is drawing a deliberate line: a conventional stick-built house can be permitted off the application alone, and a clear-span steel or post-frame shell needs a sealed set. That is 2018 IRC R301.1.3 in practice — a building with structural elements beyond the prescriptive tables of Section R301 must be designed in accordance with accepted engineering practice. We engage a Tennessee-licensed engineer to seal the structure so the drawings arrive at the counter in the form the county has already told you it wants.
Who issues the permit — the county, Johnson City or Jonesborough?
It depends on which side of a municipal line your parcel sits, and this is the first thing to settle. Washington County's Zoning Office at 100 E Main Street, Suite 103 in Jonesborough, (423) 753-1753, permits and inspects in the unincorporated area — Gray, Boones Creek, Limestone, Telford, Fall Branch, Sulphur Springs and the rest of the rural county. Johnson City runs its own Building Division at 601 East Main Street, (423) 434-6047, and its rules and design criteria are its own. Jonesborough, the county seat, also runs its own. Watauga is a fourth authority. The county's parcel viewer at gis.washingtoncountytn.org/zoningmap will tell you which applies to a specific lot, and we check it before quoting anything, because the answer changes both the inspection sequence and the fee.
Does Washington County inspect, or does the state?
The county inspects. Its Codes Compliance page states plainly that Washington County has adopted and is enforcing the 2018 International Residential Code, and lists what the County Building Inspector checks: footer, slab where applicable, framing, rough-in plumbing, rough-in mechanical, insulation, plumbing, mechanical, final, and Certificate of Occupancy. This matters in Tennessee more than it would elsewhere, because a Tennessee county can vote itself out of the residential code entirely by two-thirds resolution under T.C.A. 68-120-101(b)(1)(B)(i), and dozens have. Washington County has not. Two things do go to the state rather than the county: electrical permits and inspections, and manufactured-home set-up inspections. Inspections here must be booked by 3:00 p.m. the day before, and one re-inspection is free before the $40 fee starts.
Can I put metal siding on a barndominium in Washington County?
On a house, yes. There is a metal-siding rule in the Zoning Resolution and it is worth understanding rather than fearing. Section 622, the Corridor Overlay District, requires a Planning Commission waiver to use corrugated metal siding, vinyl siding or unpainted concrete block where they are visible from a designated roadway, and the overlay reaches 300 feet back from the front property line — with any parcel under five acres pulled in entirely if any part of it falls inside that band. But Section 622.2 exempts new and existing single-family, two-family and agricultural uses from the overlay outright. So a detached single-family dwelling is not caught by it. What is caught is conversion: turning a residential or agricultural structure into a commercial or industrial use on a corridor parcel puts you back inside the standard. If a workshop building might one day take on a commercial use, that is the conversation to have early.
How much land do I need, and is there a minimum house size?
There is no minimum house size. A full reading of the Zoning Resolution, re-adopted in October 2013 and amended in June 2026, turns up no minimum heated floor area for a dwelling in any district — which is not true of every Tennessee county and is worth knowing if your plan is compact. Lot size depends on the district and on the utilities. In A-1 General Agriculture a detached single-family dwelling needs 15,000 sq ft on public sewer, 21,780 sq ft with public water and septic, and a full acre with neither, at 100 feet of width and 30-foot front and rear yards with 12-foot sides. A-2 Agriculture-Residential is one acre for a single-family structure. R-1 Low Density Residential is 15,000 sq ft. The district also decides your workshop: R-1 caps the total floor area of all accessory structures at the area of the house, while A-1 and A-2 impose only setbacks.
What does the permit cost, and how does septic fit in?
Washington County publishes its schedule, and it is valuation-based on declared materials and labour: $225 at $1,000 or less, $275 plus $5 per additional $1,000 up to $50,000, $395 plus $4 per additional $1,000 up to $100,000, $595 plus $3 per additional $1,000 up to $500,000, then $1,795 plus $2 above that. A $5 archive fee is added, and plumbing and mechanical or gas permits are included rather than charged separately. An accessory building of 200 sq ft or more is charged on the same schedule; under 200 sq ft it is a $75 zoning compliance permit. Septic runs through the state, not the county: the Tennessee Department of Environment and Conservation on (423) 854-5400. Sequence matters here — the county wants the septic permit and the driveway permit in hand before it issues the building permit, so on an unsewered parcel the soil and site evaluation is the first thing to book, not the last.
Is this the Washington County near Bristol and the Virginia line?
It is, and the confusion is worth clearing up because it costs people real time. This is Washington County, Tennessee — county seat Jonesborough, largest city Johnson City, the anchor of the Tri-Cities. There is also a Washington County, Virginia, seat Abingdon, and it borders Sullivan County, Tennessee, which is the county immediately north of this one. Bristol straddles the state line between them. So two counties of the same name sit about forty minutes apart across a state border, running different codes under different states. If you are searching for permit rules and land in this region, check the state before you read the ordinance. Anything on this page is Tennessee: the 2018 International Residential Code as adopted by the State Fire Marshal, the Washington County Zoning Resolution, and the Washington County Zoning Office in Jonesborough on (423) 753-1753.

What clients say

4.9 out of 5 based on 8 reviews Placeholder content

We had ten acres outside town and no idea what we could legally put on it. They pulled the zoning and the A-1 lot minimum before we spent anything on drawings, which saved us from buying plans for a building that would not have been approved.

Dale W. July 18, 2026

Ordered the shell kit and erected it with my brother-in-law over about six weekends. The drawings were clear, the bolt schedule matched what showed up on the truck, and the county inspector had no issues with the engineering.

Marisol T. June 2, 2026

Turnkey from a cleared lot to certificate of occupancy. What I appreciated most was that when plan review came back with comments, I heard about it the same day along with what they were doing about it.

Ray B. April 27, 2026

Building in Washington County?

Start with the plan. Tell us what you want to build and we will draw it, then confirm what Washington County will actually let you put on the parcel and what wind load it has to meet. That conversation costs nothing.

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