Deck Building in Northglenn, CO

Deck building in Northglenn is guided by a document the city hosts and distributes itself: the Colorado Chapter ICC’s Single Family Residential Uncovered Decks and Porches building guide, written to the same International Residential Code edition Northglenn currently has codified. That guide functions as the city’s operative deck permit handout, covering everything from footing details to guardrail height to ledger attachment. Our crew builds the plan set and the framing sequence around that guide rather than a generic deck plan that was never checked against what Northglenn actually asks for.

The City’s Own Guide Sets the Permit Path

The process starts with a completed building-guide worksheet covering joist size and spacing, beam size, post size and spacing, decking type, wood species, and ledger fastener size and spacing, paired with a scaled site plan showing the deck’s dimensions and its distance to property lines. That worksheet and site plan go in with the building permit application before framing material is ordered.

We did not find a Northglenn page stating a specific small-deck exemption, the kind of rule some jurisdictions use to exempt a low, small platform from permitting entirely. Because the city’s own guide is written as the standard application handout for a residential uncovered deck, we treat a permit as the expected path for a new deck and confirm with the Building Division whether any specific low or small deck might be treated differently before assuming otherwise.

Footings: Below Frost Depth, Confirmed Locally

The city’s guide details a concrete pier footing with a minimum 8-inch diameter and a minimum ½-inch diameter anchor bolt embedded at least 7 inches into the pier, or an equivalent connection. Posts need to sit at least 6 inches above grade, or be decay-resistive lumber if the clearance is less. The pier bottom itself is specified as set below frost depth, with the guide directing builders to check the required depth with the local jurisdiction rather than printing one fixed number.

We did not find a specific frost-depth or minimum footing-depth figure stated in Northglenn’s own materials, so rather than reuse a number from a general Colorado frost-depth chart or a builder’s rule of thumb, we confirm the required footing depth with the Building Division before excavation on every project. That confirmation step also lets us account for any site-specific soil condition the standard guide would not capture.

Guardrails and Stairs Follow Fixed Dimensions

A guardrail is required once the deck’s walking surface is more than 30 inches above grade or the floor below. Where required, guardrails need to be at least 36 inches tall, with openings sized so a 4-inch diameter sphere cannot pass through anywhere in the rail assembly.

Stairways need to be at least 36 inches wide, with a maximum rise of 7¾ inches and a minimum tread run of 10 inches, and no riser or run in a single flight can vary by more than ⅜ inch from the others. Stairs need lighting, and where solid risers are used with a tread narrower than 11 inches, a nosing of ¾ inch to 1¼ inches is required. Handrails are required on any stair with four or more risers, mounted 34 to 38 inches above the nosing, with a graspable profile between 1¼ and 2¼ inches and at least 1½ inches of clearance from any adjacent wall. We frame stairs and rail posts to these numbers from the start, since retrofitting a rail height or a stair nosing after decking is installed usually means undoing finished work.

Ledger Attachment Is Where Most Deck Failures Start

The city’s guide calls for a ledger board of at least 2×8 pressure-treated lumber, grade #2 or better, and it specifically prohibits ledger support on stone or masonry veneer and attachment to a cantilevered floor. Lag-screw and bolt sizing and spacing are set out in span-based tables in the guide, along with the flashing detail required at the ledger-to-house connection to keep water from tracking behind the siding. A deck that needs to attach to a cantilevered floor structure requires engineer approval rather than a standard ledger detail.

We check the house’s existing wall construction before committing to a ledger-attached design. Where the wall framing does not support a standard ledger connection, a freestanding deck design, supported entirely on its own posts, is often the more reliable option than forcing a ledger onto a wall that was not built to carry it.

Structural Loads, Wind, and Egress

Northglenn’s guide provides joist, beam, and post span tables sized for a 40 psf live load and a 10 psf dead load, covering Southern pine and Douglas fir-larch, hem-fir, or spruce-pine-fir lumber graded #2 or better; engineered lumber and other species fall outside the guide and need review by the Building Division. In higher-wind conditions the guide points builders to the applicable lateral-load connection requirements and to the local jurisdiction for any additional connector requirements, consistent with the same 110 mph, Wind Exposure Category B design criteria the city’s building department has published elsewhere.

Where a deck or porch is built over a walk-out basement or patio egress window, the guide requires the covered path over that window to stay at least 36 inches high to a yard or court, or 6 feet 8 inches where the window serves as a walk-out basement escape. We check for a below-deck egress window early in design, since it can change joist layout and stair placement, not just deck height.

Setbacks Need a Zoning Check, Not a Guess

The city’s deck guide does not set its own separate deck setback distance; setback comes from the underlying zoning for the parcel. Rather than reuse a generic setback figure from an unrelated project type, we confirm the applicable setback for the specific zone district through the city’s zoning tools or the Planning Division before finalizing a deck’s footprint, since an attached deck can be treated similarly to other structures under the zoning code for that district.

How We Sequence a Northglenn Deck

We start with a site visit to check the house’s wall construction for ledger feasibility, confirm the zoning setback for the parcel, and identify any below-deck egress window. The building-guide worksheet is completed with joist, beam, post, and ledger details specific to the design, paired with a scaled site plan, and submitted with the permit application.

Once the permit is issued, we request a utility locate through Colorado 811 before excavating footings, confirm the required footing depth with the Building Division, and set posts and footings for inspection before backfilling. Framing, ledger flashing, guardrails, and stairs follow the dimensional requirements in the city’s guide, with a final inspection closing out the permit once the deck is complete.

Common Questions

Does every new deck in Northglenn need a permit?
The city’s own deck guide is written as the standard permit-application handout for a residential uncovered deck, and we did not find a stated small-deck exemption on an official Northglenn page. We confirm with the Building Division before assuming any deck is exempt.

How deep do deck footings need to be in Northglenn?
The city’s guide says footings must be set below frost depth and directs builders to confirm the specific depth with the local jurisdiction. We did not find a fixed number published by Northglenn itself, so we confirm the required footing depth with the Building Division before excavating.

When does a Northglenn deck need a guardrail?
Once the deck’s walking surface is more than 30 inches above grade or the floor below. Required guardrails must be at least 36 inches tall with openings that do not allow a 4-inch sphere to pass through.

Do deck setbacks change by neighborhood in Northglenn?
Yes. The city’s deck guide does not set its own separate setback; setback comes from the zoning district for the specific parcel, so we confirm the applicable distance before finalizing a deck’s footprint.

Talk to Us About Your Project

Tell us your home’s construction type, whether you want the deck attached to the house or freestanding, the approximate size and height above grade, and whether there is a walk-out basement window nearby. We will confirm the current setback, footing, and permit requirements with Northglenn’s Building Division before finalizing the plan.