NRCS High Tunnel Requirements: The CPS 325 Checklist for 2026

NRCS HIGH TUNNEL REQUIREMENTS: THE CPS 325 CHECKLIST FOR 2026

By Toby Fischer, Co-owner, CT Greenhouse · Updated July 2026

If you're planning to use NRCS funding for a high tunnel, your structure needs to meet a specific set of technical requirements called Conservation Practice Standard 325 (CPS 325). The good news: the requirements are straightforward, and most commercial high tunnel kits already meet them. Here's the complete checklist so you know exactly what your kit needs before you start the EQIP application process.

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1. What Is CPS 325?

CPS 325 covers everything from your frame material and covering thickness to how you grow crops inside the tunnel. If your structure doesn't meet these standards, your NRCS reimbursement won't be approved. The requirements are the same nationally, but your state may have additional implementation guidelines on top of the base standard. Always confirm the details with your local NRCS office before you purchase a kit.

For a full overview of the NRCS high tunnel program, including payment rates and how to apply, see our Complete Guide to the NRCS High Tunnel Grant.

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2. Structure Requirements Under CPS 325

Here's every technical requirement your high tunnel needs to meet according to CPS 325. Use this as a pass/fail checklist when evaluating kits.

Requirement	NRCS Minimum Standard
Structure type	Pre-fabricated kit from a commercial manufacturer. No DIY or homemade structures.
Peak height	Minimum 6 feet at the center peak
Frame material	Metal, wood, or durable plastic. Galvanized steel is most common and preferred for longevity.
Bow spacing	Varies by state, generally 4,5 0r 6 feet between bows.
Cover material	6 mil greenhouse plastic, shade cloth, bug netting or polycarbonate
Ventilation	Passive ventilation typically expected (roll-up sides, end wall vents, or removable panels)
Installation	Must be built according to the manufacturer's specifications and instructions

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3. Growing Rules Under CPS 325

CPS 325 isn't just about the structure itself. It also governs how you use it. The core rule is simple: crops must be grown in the ground.

• In-ground growing required: Crops must be planted directly in the natural soil profile
• Raised beds are OK: Permanent raised beds are permitted, but they can't exceed 12 inches in height
• No containers or tables: Growing in pots, on benches, or using hydroponic systems is not eligible under CPS 325
• Seasonal management: You're responsible for managing the cover during severe weather. If your tunnel isn't rated for your local snow or wind loads, you may need to remove or roll up the plastic seasonally

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4. What's NOT Covered Under CPS 325

The list of what CPS 325 doesn't cover is actually pretty short. Here's what falls outside the standard:

• DIY or homemade structures built from raw materials
• Container or hydroponic growing (pots, benches, tables)
• Livestock housing or equipment storage
• Irrigation lines, land costs, or site grading (these are separate from the high tunnel practice)

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5. Size and Dimensions: Does NRCS Have a Limit?

The most commonly cited payment cap is around 2,178 square feet (roughly a 30' x 72' structure), but this varies by state. Some states fund larger structures, and some set lower caps. The payment is calculated as a flat rate per square foot, not a percentage of your actual cost, so your out-of-pocket amount depends on both the state rate and the kit you choose. Some states cap the dollars rather than the footprint. 

Before you settle on a size, call your local NRCS office to get your state's current payment cap and rate per square foot. That way you'll know exactly how much of the cost is covered before you commit. 

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6. How CT Greenhouse Kits Meet CPS 325

All three CT Greenhouse high tunnel models are designed to meet or exceed every CPS 325 requirement, so picking the right kit comes down to fit rather than eligibility. Here's a quick look at how each model stacks up:

CPS 325 Requirement	Grower	Plus	Pro
Pre-fab kit	✓	✓	✓
6-ft+ peak height	✓	✓	✓
Galvanized steel frame	✓	✓	✓
6-mil UV poly cover	✓	✓	✓ Double-layer
4-ft bow spacing	✓	✓	✓
Passive ventilation	Roll-up sides	Roll-up sides + peak vents	7-yr woven roll-up sides

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Frequently Asked Questions

What are the requirements for the USDA high tunnel program?

Your high tunnel must meet Conservation Practice Standard 325 (CPS 325). The key requirements are: a pre-fabricated commercial kit, minimum 6-foot peak height, 6-mil UV-resistant polyethylene cover, metal or durable frame, and in-ground or raised-bed growing (12-inch max bed height). The structure can't be used for livestock or storage.

Does NRCS have a size limit for high tunnels?

No. There's no federal size limit for NRCS high tunnels. However, most states set a payment cap or size that limits reimbursement to a specific square footage. You can build larger, but you'll cover the cost difference yourself. Check with your local office for your state's current cap.

Can I build my own high tunnel and get NRCS funding?

No. CPS 325 requires a manufactured kit from a commercial supplier. DIY or homemade structures built from raw materials don't qualify for EQIP cost-share. You can assemble the kit yourself, but the tunnel itself must be a pre-fabricated product with manufacturer specifications and instructions.

What cover material does NRCS require?

NRCS requires a minimum 6-mil, greenhouse-grade, UV-resistant polyethylene cover (or equivalent material) with at least a 4-year lifespan. Standard hardware store plastic sheeting won't meet this standard. All CT Greenhouse kits come with greenhouse-grade poly that meets or exceeds this requirement.  You can also use shade cloth, polycarbonate or bug netting in some states. 

Are CT Greenhouse high tunnels NRCS-eligible?

Yes. All three CT Greenhouse models (Grower, Plus, and Pro) are designed to meet every CPS 325 requirement. They're pre-fabricated kits with galvanized steel frames, 6-mil UV poly covering, 4-foot bow spacing, and passive ventilation. We've worked with growers across multiple states to fulfill their NRCS contracts. That said, always confirm your specific kit with your local NRCS agent before purchasing.

Next Steps

CPS 325 is straightforward once you see all the requirements in one place. If the kit you're considering checks every box in the table above, you're in good shape. Your next step is to start the application process with your local NRCS office; application windows follow your state's NRCS ranking dates. And if you want a kit that's already been through the process with hundreds of growers, take a look at what we offer.