Colorado Building Permits for Sheds, Greenhouses & Saunas: What You Need to Know

A Complete Guide from South Table Sheds | 17 Years Serving the Denver Metro Area

If you're planning to add a shed, greenhouse, or sauna to your Colorado property, one of the first questions you'll face is: Do I need a Colorado building permit?

The answer depends on where you live, what you're building, and how you're building it. Colorado building permits are handled at the local level, which means requirements vary significantly from Denver to Jefferson County to Colorado Springs. After 17 years of helping Front Range homeowners navigate these requirements, we've learned that a little research upfront saves a lot of headaches later.

This guide covers what you need to know about Colorado building permits for backyard structures, including some surprises that catch homeowners off guard.

The 200 Square Foot Rule (And Why It's Not That Simple)

Across most Colorado jurisdictions, 200 square feet is the magic number. Detached accessory structures under this threshold typically don't require a building permit. This applies to sheds, greenhouses, and sauna structures alike.

But here's where it gets complicated:

Height matters too. Most jurisdictions also have height limits for permit-exempt structures, typically 8 to 14 feet depending on the area. A tall greenhouse or two-story shed might trigger permit requirements even if it's under 200 square feet.

Denver is different. The City and County of Denver requires a zoning permit for ALL accessory structures, regardless of size. Even a 100 square foot shed needs zoning approval in Denver.

Boulder County is stricter. Boulder County only exempts structures up to 120 square feet, not the typical 200.

Colorado Springs adds zoning review. While structures under 200 square feet don't need a building permit, anything 125 square feet or larger requires zoning approval in Colorado Springs city limits.

Jefferson County has cumulative limits. JeffCo caps "mini-structures for storage" at a cumulative 200 square feet total. If you already have a 150 square foot shed, adding another 100 square foot structure would exceed the limit.

Understanding Colorado Building Permits: Zoning vs. Building

One common source of confusion: there are actually two types of permits to consider.

Zoning permits govern WHERE you can build. They ensure your structure meets setback requirements (distance from property lines), lot coverage limits, and land use regulations. Even permit-exempt structures must comply with zoning rules.

Building permits govern HOW you build. They ensure structural integrity, proper foundations, and compliance with building codes for wind loads, snow loads, and safety.

A structure might be exempt from building permits but still require zoning review—or vice versa. Always check both.

Colorado Building Permits for Sheds

Storage and Garden sheds are the most straightforward of the three structure types, but there are still nuances to understand.

When You Typically DON'T Need a Building Permit:

• Detached shed under 200 square feet (120 sq ft in Boulder County)

• Single-story with height under local limits (usually 8-14 feet)

• Placed on grade or gravel pad (not permanent foundation)

• Used strictly for storage (not habitation or workspace)

When You Likely WILL Need a Building Permit:

• Shed over 200 square feet

• Shed with electrical wiring

• Shed on a concrete foundation

• Attached to your home or garage

• Located in Denver (zoning permit required for all sizes)

Pro tip: Even if your shed doesn't need a permit, it must still meet setback requirements. Most jurisdictions require structures to be a certain distance from property lines—typically 3 to 5 feet for side and rear setbacks, more for front yards.

Colorado Building Permits for Greenhouses

Greenhouses follow similar rules to sheds, but with a few important distinctions.

Freestanding vs. Attached A Critical Difference

This is the biggest factor for greenhouse permits in Colorado:

Freestanding greenhouses are treated as accessory structures. Under 200 square feet, they typically don't require a building permit (same rules as sheds).

Attached greenhouses (lean-to style against your home) are treated as home additions. They require full building permits regardless of size, including structural review and potentially impacting your home's heating and cooling systems.

Barrel Outdoor Sauna | 6 Person

$6,498.00

Everything You Need for an Authentic Sauna Experience This barrel outdoor sauna arrives complete with premium components from trusted manufacturers. From the Finnish-made Harvia heating system to thoughtful comfort features, every element is included so you can start enjoying your… read more

Add to cart

Colorado-Specific Considerations

Snow loads: Colorado's Front Range requires structures to handle significant snow loads—minimum 30 pounds per square foot in most areas. For larger greenhouses requiring permits, you may need engineered drawings demonstrating compliance.

Wind loads: Many Front Range areas have wind speed requirements of 115+ mph for structural calculations.

Agricultural exemptions: Some rural areas and agricultural zone districts have exemptions for farm structures. If you're on agricultural land, ask your building department about potential exemptions.

Colorado Building Permits for Saunas

Saunas are where Colorado building permits get interesting. The structure itself follows the same 200 square foot rule, but the heater introduces additional requirements.

Electric Sauna Heaters

Most traditional sauna heaters require 240V electrical service. This means:

• Electrical permit required in virtually all Colorado jurisdictions

• Installation must be done by a licensed electrician

• Inspection required before use

The good news: electric heaters don't require EPA certification or face air quality restrictions. We offer Harvia KIP electric heaters that provide an authentic traditional sauna experience without the regulatory complications of wood-burning options.

Wood-Burning Sauna Stoves

Wood-burning saunas face additional hurdles in Colorado:

Mechanical permit required: Wood stove installation typically requires a mechanical permit and inspection.

Air quality regulations: In the seven-county Denver metro area (Denver, Boulder, Broomfield, Douglas, Jefferson, and portions of Adams and Arapahoe counties below 7,000 feet), wood-burning devices must be EPA Phase III certified. Many popular Finnish sauna stoves are NOT EPA certified.

Action Day restrictions: Non-certified wood-burning devices cannot be used during air quality Action Days (November through March).

Mountain exemption: Properties above 7,000 feet elevation are exempt from these restrictions, making wood-burning saunas more practical in mountain communities like parts of Evergreen and Conifer.

How Foundation Type Affects Colorado Building Permits

The type of foundation you choose can significantly impact permit requirements for any backyard structure.

Gravel pad or placed on grade: Treated as temporary or accessory structures. This is the easiest path for permit-exempt sheds, greenhouses, and saunas under 200 square feet.

Concrete slab: A permanent foundation often triggers permit requirements regardless of structure size. Some jurisdictions require a permit for the concrete work itself before you even build the structure.

Attached to existing structure: Any structure attached to your home—whether a lean-to greenhouse, shed addition to a garage, or indoor sauna conversion—is treated as a home addition requiring full building permits.

For most customers, we recommend freestanding structures on gravel pads. It simplifies the permit process and gives you flexibility to relocate the structure later if needed.

Don't Forget Your HOA

Colorado building permits are only part of the equation. If you live in a community with a homeowners association, you'll likely need architectural approval—and HOA rules can be stricter than local building codes.

• HOAs can restrict structure size, placement, materials, and colors

• Some prohibit certain structure types entirely

• Wood-burning saunas often face extra scrutiny due to smoke

• Approval can take 30-60 days or more

Critical advice: Always get written HOA approval BEFORE purchasing any backyard structure. We've seen too many homeowners buy a shed or greenhouse only to have their HOA reject it after the fact.

Colorado Building Permits: Quick Reference by Jurisdiction

Here's a snapshot of requirements across major Front Range areas:

Denver

• Zoning permit required for ALL accessory structures

• Building permit if over 200 sq ft or over 8 ft tall

• Air quality restrictions on wood-burning devices

Jefferson County (Unincorporated)

• No building permit for structures under 200 sq ft and under 14 ft tall

• Cumulative 200 sq ft limit on mini-structures

• Mountain areas may require Defensible Space Permit

Golden

• No building permit for detached structures under 200 sq ft

• Pools, hot tubs, spas require permits

Colorado Springs / Pikes Peak Region

• No building permit for structures under 200 sq ft

• Zoning approval required if 125 sq ft or larger (city limits)

• Outside Denver metro air quality restricted area

Fort Collins / Larimer County

• Prefab structures typically don't require building permits if under 200 sq ft

• Outside Denver metro air quality restricted area

Boulder County

• More restrictive: only 120 sq ft exempt

• Structures with utilities typically require permits

• 12 ft height limit for exempt structures

What Happens If You Skip the Permit?

We understand the temptation to skip the paperwork, but here's why it's not worth the risk:

Stop work orders: If inspectors notice unpermitted construction, work stops until permits are obtained.

Sale complications: Unpermitted structures discovered during home inspections can derail real estate transactions.

Insurance issues: Damage to or caused by unpermitted structures may not be covered. This is especially critical for saunas with unpermitted electrical work.

Forced removal: In worst cases, you may be required to remove non-compliant structures entirely.

Retroactive permitting: Getting permits after the fact is often more expensive and complicated than doing it right the first time.

Questions to Ask Your Building Department

Before purchasing any backyard structure, call your local building department with these questions:

1. What's the maximum size for a permit-exempt accessory structure?

2. Are there height restrictions?

3. What are the setback requirements for my property's zoning?

4. Do I need a zoning permit even if no building permit is required?

5. Is my property in any overlay districts (flood plain, historic, wildfire)?

6. For saunas: Do I need an electrical permit for a 240V heater?

7. For saunas: Are there air quality restrictions on wood-burning devices?

8. For greenhouses: Does an attached greenhouse require different permits than freestanding?

Pro tip: Know your property's zoning designation before you call. Most Colorado counties have online maps where you can look this up.

How South Table Sheds Can Help

At South Table Sheds, we've spent 17 years helping Denver metro homeowners navigate Colorado building permits for outdoor structures. While we guide you through the research process, homeowners handle the actual permit filing, which ensures you're working directly with your local jurisdiction.

Here's what we provide:

• Help identifying which jurisdiction governs your property

• Consult for permit applications

• Knowledge of common requirements across Front Range municipalities

• Guidance on placement to comply with typical setback requirements

• For saunas: electric heater options that simplify the permit process

Whether you're looking for a storage shed, a greenhouse to extend your growing season, or a backyard sauna for year-round relaxation, we're here to help you do it right.

Contact us to discuss your project, or browse our selection of sheds, greenhouses, and saunas online.

South Table Sheds

Serving the Denver Metro Area for 17 Years

Sheds | Greenhouses | Saunas | Cold Plunges