Deck Building in Broomfield, CO

A new deck in Broomfield is a structural permit project from the first sketch, reviewed by the same Building Division that handles roofing and siding permits. Broomfield’s own permit guidance names decks specifically as work that requires a permit, and the structural detailing that follows — footings, ledger attachment, guardrails, and stairs — is governed by the 2024 International Residential Code the city has adopted. Apollo Construction plans a Broomfield deck around those code sections rather than a generic deck layout.

Decks Are a Named Permit Item, Plan Set Required

Broomfield’s building-permit guidance lists decks among the residential projects that require a permit, and a Broomfield-oriented building guide developed under the city’s adopted 2024 IRC calls for a plot plan showing the deck’s dimensions and its relationship to the existing house and property lines, plus a section drawing showing post size, beam size, joist size and spacing, and footing depth. We were not able to confirm an official minimum size or height below which a Broomfield deck permit is waived, so even a modest deck addition should be confirmed with the Building Division before it’s treated as permit-exempt.

Footings Go Below Frost Depth, With Specific Pier and Anchor Details

The adopted-code deck guide calls for a minimum 8-inch diameter concrete pier, with a half-inch-diameter anchor bolt embedded at least 7 inches into the pier to secure the post. Posts need at least 6 inches of clearance above finished grade unless the post material is decay-resistant. The guide is explicit that footing depth has to go below the local frost depth and directs the applicant to confirm that specific number with the jurisdiction rather than printing one figure for every site — we do that frost-depth confirmation with the Building Division as part of the plan set rather than assuming a number from a neighboring project.

Ledger Attachment Has Its Own Table, and Masonry Veneer Is Excluded

Where a deck attaches to the house, the ledger board has a minimum size of 2×8 pressure-treated lumber (Hem-Fir, Douglas Fir, or Southern Pine grade #2 or better), and it may not be supported by a stone or masonry veneer wall — that detail requires an engineered connection instead. Attachment to a cantilevered floor also requires engineering design with the Building Division’s approval. Fastener spacing for the ledger-to-band-joist connection is set out in a code table keyed to joist span, and the design load assumptions behind that table are a 40 psf deck live load, 40 psf snow load, and 10 psf dead load — a site with snow loads above 40 psf needs to be confirmed with the jurisdiction separately.

Guardrails Trigger at 30 Inches, With a 36-Inch Minimum Height

Any deck walking surface more than 30 inches above grade requires a guardrail, and that guardrail has to be at least 36 inches tall with balusters spaced so a 4-inch-diameter sphere cannot pass through. Stairways attached to the deck have their own dimensional rules: minimum 36-inch width, maximum 7¾-inch riser height, minimum 10-inch tread run, and no more than a ⅜-inch variance in riser or run across the full flight. Stairs need illumination, and open risers are only allowed where the opening is under 4 inches.

Handrails are required on any stair with four or more risers, continuous on at least one side, with the top surface set 34 to 38 inches above the stair nosing and a graspable profile the guide details down to the eighth of an inch. We treat the guardrail and handrail thresholds as fixed points in the design, not adjustable finish details, since they’re the parts of a deck plan Broomfield’s inspectors check most directly against the code tables.

Setbacks Are a Planning Question the Structural Guide Doesn’t Answer

The structural deck guide Broomfield’s Building Division points to is a framing and connection reference; it does not state zoning setback distances from the property line, and we were not able to confirm a specific Broomfield deck setback figure during this research. That number depends on the zone district and, for PUD-zoned lots, on the property’s Site Development Plan, so we confirm setback with the Planning Division before finalizing a deck’s footprint, in addition to the structural review the Building Division performs.

How We Sequence a Broomfield Deck Project

We start with a site plan showing the deck’s footprint against the house and property lines, and confirm setback with the Planning Division before the structural plan set is finalized, since a structurally sound deck can still fail review on location. The structural plan — post size and spacing, beam size, joist size and spacing, ledger connection detail, and footing depth relative to the confirmed local frost depth — is built to the 2024 IRC deck tables the city has adopted.

On site, footings are set to the confirmed frost depth and anchor-bolt embedment before framing begins, and any ledger attachment to a cantilever or masonry veneer wall is flagged for engineering before installation, not after. Guardrails and stair handrails are built to the 30-inch/36-inch and 34–38-inch thresholds from the first framing pass, so the completed deck is ready for the Building Division’s inspection rather than needing rework at that stage.

Common Questions

Does every new deck in Broomfield need a permit?
Broomfield’s building-permit guidance names decks as a project that requires a permit, and the city’s structural deck guide calls for a full plot plan and section drawing. We were not able to confirm any size or height below which a deck is permit-exempt, so confirm with the Building Division before assuming one applies.

How deep do deck footings need to be in Broomfield?
Footings must extend below the local frost depth, with piers at least 8 inches in diameter and posts at least 6 inches above finished grade unless decay-resistant. The exact frost-depth figure needs to be confirmed with the Building Division for the specific site.

When does a Broomfield deck need a guardrail?
Any deck walking surface more than 30 inches above grade requires a guardrail at least 36 inches tall, with balusters spaced so a 4-inch sphere cannot pass through.

Can a deck ledger attach to a stone or masonry veneer wall in Broomfield?
No. The city’s adopted deck guide states the ledger may not be supported by stone or masonry veneer; that connection requires an engineered design instead of a standard ledger attachment.

Talk to Us About Your Project

Tell us the deck’s approximate size, attachment point, and height above grade, and we will map the Broomfield footing, ledger, guardrail, and setback steps before the plan set is drawn.