What is a high tunnel, and how is it different from a greenhouse?
A high tunnel is an unheated, plastic-covered structure tall enough to walk and work in. Crops grow in the ground, not on benches. Ventilation comes from roll-up or drop-down sides and end-wall doors, not fans.
NRCS sets the minimum for a cost-shared tunnel. Its practice 325 summary requires a frame at least 6 ft tall at the peak, constructed end walls, and crops "grown in the natural soil profile, or in raised beds up to 12 inches in height." Tables, benches, pots and hydroponics fall outside the practice.
A greenhouse adds what a tunnel leaves out: rigid glazing, heat, powered ventilation, a foundation. If you want year-round heated growing for a business, our commercial greenhouse construction page is the better fit.
Which tunnel size should you build?
Width sets the bow spacing, the snow and wind load each bow carries, and how many beds fit. Length is cheap to add once the end walls are paid for. Three common sizes:
| Tunnel (W × L) | Floor area | Typical layout | Build notes |
|---|---|---|---|
| 20 × 48 ft | 960 sq ft | 3 beds, one center aisle | Walk-in doors; lighter bows; easiest to film on a calm morning |
| 30 × 72 ft | 2,160 sq ft | 4–5 beds | Tractor-width end door possible; end walls carry more wind |
| 30 × 96 ft | 2,880 sq ft | 4–5 beds | A common long single-span size; more bows, same two end walls |
On the FY26 Kansas EQIP schedule, the 30 × 72 ft tunnel works out to $5,453.95 + (2,160 × $4.79) = $15,800.35 (payment schedule). The grant guide works all three sizes at both the standard and historically underserved rates.
For benchmarks, Rutgers found basic high tunnel kits typically run $3 to $6 per sq ft, with delivery and installation excluded (Rutgers Farm Viability, Apr 2026). A University of Florida budget for a 30 × 84 ft tunnel came to $6.16–$6.72 per sq ft with installation, about a third of the total, using 2017 pricing (UF/IFAS). Our installed price depends on width, bow spacing, end-wall framing, door count and site prep. We will quote it against your site.
What goes into a tunnel built for Kansas weather?
End walls
NRCS requires them. Most of the wind load on a tunnel lands on the end walls, so that is where we frame heaviest. Options run from framed lumber with film to framed polycarbonate panels. A double door or a roll-up door lets a small tractor or a wheelbarrow through.
Roll-up sides
Hand-crank roll-up sides are the standard. They vent heat on a sunny January afternoon and close before a north wind. Hip boards should be treated or rot-resistant lumber, which the NRCS summary also calls for.
Ground posts vs. anchors
Bows sit in ground posts, short steel sleeves driven or set in concrete. In loose or sandy soil, posts get concrete collars or earth anchors added. In the clay soils common on the east and south sides of the county, deeper posts help.
Wind is the design driver here. MABCD's local design table lists a 15 psf ground snow load and "76w/90-3 sec. gust" wind, one older value written two ways: 76 mph fastest-mile = 90 mph 3-second gust (Sec. 2.4.115, UBTC). Derby's code lists the same (Ord. 2623). Current maps give 115 mph ultimate (Meltplan), about 89 mph in allowable-stress terms. We size bows and anchors with margin over those minimums, to at least 20 psf snow. A rough check shows why anchors matter: velocity pressure is 0.00256 × V², and 0.00256 × 115² = 33.9 psf before exposure and shape factors. A 30-ft-wide end wall of about 270 sq ft sees on the order of 9,000 lb at that pressure. An engineer's numbers will differ, but the scale is real. Our wind-rated design guide runs the full method.
Snow and film
At a 20 psf design snow (the code minimum here is 15), a 30 × 96 ft footprint holds 57,600 lb if the film can't shed it. NRCS tells growers to "remove the cover prior to the 'snow season' unless the structure has been designed for expected snow loads." Gothic (peaked) bows shed snow better than round bows.
For film, NRCS requires "a minimum of 6 millimeter [6-mil] greenhouse grade, UV-resistant material" with "a min. 4-year lifespan." Plan to re-skin on roughly that cycle.
Hail
Poly film is not hail-proof. The Wichita area logged 333 hail reports within 10 miles since 2004 (stormersite), and the September 15, 2010 storm dropped a 7.75-inch stone in southwest Wichita. Film is cheap to replace, which is part of why tunnels make sense here. Our hail guide covers rigid glazing and insurance.
Do you need a permit for a high tunnel around Wichita?
It depends on where you build and what the tunnel is for.
| Location | Rule for a hoop house / high tunnel | Source |
|---|---|---|
| Wichita, unincorporated Sedgwick County and Derby | Residential polyethylene hoop houses are excluded from building-code requirements; zoning still applies | Sec. 2.4.035, UBTC; Ord. 2623 |
| Wichita city, other structures | Accessory structures ≤200 sq ft exempt from a building permit; a location permit is still required | Ord. 50-833 |
| Unincorporated Sedgwick County, other structures | Accessory structures ≤400 sq ft exempt from a building permit; a location permit is still required | Res. 080-2017; Ord. 50-833 |
| Ag land, county | K.S.A. 19-2921 exempts ag buildings from county zoning; MABCD still lists agricultural buildings as permitted work | AG Op. 2018-004; MABCD Permits |
Residential hoop houses. The Wichita–Sedgwick County code (Sec. 2.4.035, UBTC) and Derby's Ordinance 2623 use the same words: "Hoop Houses" are excluded from building code requirements, defined as a poly-tunnel, "hoop greenhouse or hoop house, or high tunnel" made of polyethylene. The catch: "Hoop houses, within this definition, are for residential use only." Setbacks and easements still apply. Derby doesn't say whether a zoning or accessory permit is still needed, so ask the city. See our Derby page.
Farm tunnels. A tunnel used to grow for sale is not "residential use," so the exclusion doesn't reach it. Almost every working tunnel is bigger than 200 or 400 sq ft; a 20 × 48 is already 960. On agricultural land in the county, zoning is exempt, but MABCD has no general ag exemption from building permits. Its Permits page lists "Detached Accessory Structures or Agricultural Building" as permitted work, with a site plan, a road approval permit and a fee of $0.20 per sq ft of unfinished space. An ag-use property owner statement may also be part of the process. Full detail is in the Wichita greenhouse permit guide.
How the EQIP money fits the build
EQIP pays after the tunnel is installed and checked against NRCS standards. The NRCS high tunnel page lists the steps: plan with your local field office, apply, get ranked, sign a contract, then build to spec within the set time. You don't buy the kit first and apply later.
The FY27 payment schedule isn't posted yet; the FY26 rates on this page are the latest (payment schedules). Water for the tunnel is its own question; see our Equus Beds well-water guide.
Who installs high tunnels in Kansas?
Kansas growers have good free help. The Kansas Rural Center publishes Growing Under Cover, built on input from more than 60 Kansas high tunnel growers. K-State's high tunnel video series covers design and crops. What growers usually lack is a crew to set posts, raise bows and pull film on a calm morning. That is the job we quote. Timing depends on season, permits and materials; your quote gives a schedule. If you plan to sell, our Kansas winter markets guide covers where tunnel crops go November through February.
Frequently asked questions
How much does NRCS pay for a high tunnel in Kansas?
For FY26, the standard rate is $5,453.95 per tunnel plus $4.79 per square foot. A 30 × 72 ft tunnel works out to $15,800.35. Historically underserved producers get $6,544.74 plus $5.75 per square foot.
Do I need a permit for a backyard hoop house?
In Wichita, unincorporated Sedgwick County and Derby, residential polyethylene hoop houses are excluded from the building code. Setbacks, easements and floodplain rules still apply, so check with the city or MABCD before you set posts.
How long does high tunnel plastic last?
NRCS requires 6-mil, greenhouse-grade, UV-resistant film with a minimum 4-year lifespan for cost-shared tunnels. Plan to re-skin on roughly that schedule.
Can I grow in raised beds or pots in an EQIP tunnel?
Raised beds up to 12 inches tall are allowed. Benches, pots and hydroponics are not covered by practice 325.
Will a high tunnel survive Wichita wind?
It can, if the bows are anchored, the end walls are braced and the sides are closed before a storm. Design against the 115 mph ultimate wind on current maps, which lines up with the 90 mph 3-second gust in MABCD's table.
Should I take the plastic off in winter?
NRCS says to remove the cover before snow season unless the tunnel is designed for the expected snow load. Gothic bows and closer bow spacing help.
Get a quote
Send us your planned tunnel size, the address and whether EQIP is in the picture. We'll come back with a layout, an anchoring plan for your soil and a price.