Department Contact
Back to our Homepage
Navigation Bar Skip Navigation City Council Contact Us Search City Government

On The Side

More Information


Deck Permits

Please refer to PERMITS for an overview of the permit process.


Applying for Permits

Provide two sets of plans and complete the following:

(Return to top)

General Permit Information

A building permit is required anytime there is an addition, alteration, repair or demolition to the main structure or accessory structure on a lot or parcel.

The issuance of permits and subsequent inspections of the work performed ensures that all construction in the city is safe and in compliance with the City of Longmont Land Development and Building Codes. The primary purpose of these codes is to ensure a safe and healthy environment for the citizens of Longmont.

Permits are reviewed and issued at the Building Inspection Division office located at the Development Services Center, 385 Kimbark St. The office is open from 8:00 AM to 5:00 PM Monday through Friday. Call (303) 651-8332 for additional information.

As a homeowner you can act as your own contractor and do the work without a contractor's license on your own property where you live. However, if you subcontract a project, electrical wiring for example, then the subcontractor must be licensed to work in Longmont. You may as a homeowner be issued a permit for subcontracted work; however, you are also responsible for inspections and sign-offs on the permit card.

CAUTION: If you do work, or have any work done without obtaining a permit, you could be incurring liability in the event of a fire or accident related to the work. In some circumstances, your insurance could be invalidated.

Please Note:
NOISE: Section 10.20.100 of the Longmont Municipal Code prohibits making unreasonable noise which would cause a person of ordinary sensitivities significant annoyance and irritation.
CONSTRUCTION DEBRIS & TRASH: Section 9.04 of the Longmont Municipal Code requires debris and trash be contained on the job site.
BEFORE DIGGING: ALWAYS call the Utility Information Center at 1-800-922-1987 to locate underground utility lines. Allow 3 working days for the lines to be located and marked.

(Return to top)


Requests for inspections are recorded on the Building Inspection Selectron System by dialing (303)774-4595. You need your permit card when calling this system, as it will prompt you for the permit and inspection numbers listed on that card. Inspections are usually made on the following day. It is wise to anticipate when they need to be made to prevent delays. No inspection will be made on subcontracted work done by an unlicensed subcontractor.

A good rule of thumb is that you should not proceed to cover up any work that has not been inspected. Although you may request either morning or afternoon inspection times, it may not be possible to schedule a specific time for the inspector to be there. You SHOULD NOT schedule any concrete or other major work for the same day as the inspection to avoid costly problems. Inspections must be called in the day before needed in order to efficiently schedule and route the Field Inspectors.

Please have all animals including dogs under control and not in the areas to be inspected. Even a normally friendly dog can become a nuisance to inspectors. Inspections will not be made if there are animals running loose and a re-inspection fee may be assessed if this occurs.

The final inspection is the last step in the inspection process and is your certification that the work has been satisfactorily completed according to the building code.

Most decks require only two inspections. Please use the following information to plan for these:



(Return to top)

General Information

Decks that are less than 24" above grade, (measured from top of finished floor of deck to grade) may be placed anywhere on the property except in easements.

E1, E2
R1, R2, R3, RLE, RMD
Front yard
Rear yard
Side yard One foot for every 2 1/2 feet or fraction thereof of building height; height being measured from 1/2 the peak of the house to the ground. Affordable housing requires a minimum of 3'-0 side yard setbacks
Other Structures: 5 feet away from sheds, detached garages, etc.

PLEASE NOTE: If the property is in a Planned Unit Development District (PUD), the setbacks are as specified on the Plat Map for the development. You may call Building Inspection for setback information.

Decks that are more than 24" above grade must be placed at minimum setback distances away from property lines. This is dependent upon the zone in which they are located as specified in the Longmont Municipal Code Section 19.16.010.

Redwood is unsuitable for Structural Members (i.e. beams, joists and ledger boards, etc.) Redwood may be used for posts, decking, handrails and trim. Pressure treated or approved wood of natural resistance to decay must be used when wood joists are less than 18" or wood beams are less than 12" above exposed earth.

The minimum depth is 30" below grade level; minimum diameter is 8". Footings/Caissons which support large loads or are constructed on soils with low bearing capacities, may be required to be larger. Call for caisson inspection before pouring caissons.

Posts are attached to the caissons below and the beams above with suitable anchors and brackets. Posts are required to be a minimum of 4"X4" nominal dimension. Redwood may be used if it is relatively free of knots and splits; otherwise pressure treated lumber may be required.

The minimum ledger size shall be the same size as the joists. Ledger boards are attached to the house with lag bolts that are at least 3/8" in diameter and long enough to go through the ledger board, siding, and they shall also penetrate fully into the rim joist or other backing inside the wall. THE DECK SHALL NOT BEAR ON ANY PART OF A HOUSE CANTILEVER.

These are placed diagonally between the posts and beams and may be required for decks built high enough to cause swaying.

Beams and joist sizes are determined by a 40 psf live load, and a 10 psf dead load, in combination with span lengths, and floor area supported. Because there are many combinations of span and floor area, this pamphlet will not attempt to address all of these. The minimum sizes will be verified with the aid of a computer program by the Building Inspection office upon review of your project. TJI's, LVL's and other laminated materials not specifically manufactured and labeled for exterior applications are not suitable and cannot be used.

BEAMS. Beams are attached to posts below with suitable metal ties. Beams may cantilever out from posts 1'-0" maximum. Beams may be either one solid piece of lumber, or more commonly two boards of equal size may be attached together forming one solid member and spliced above post.

JOISTS. Joists may be attached on top of the Ledger Board or to the side with joist hangers. They may be attached on top of the beams with solid blocking between them. Another method of attachment is with joist hangers in order to be "flush" on top with the top of beam, in this case it is required that the beam be either one solid piece or two or more boards securely fastened together to form one solid member and spliced above post.

Galvanized nails must be used to secure joist hangers, post anchors or framing anchors to framing members. Non corrosive screws may be used only to secure decking to joists.

Redwood, Pressure Treated wood and even the new Plastic/Resin Composites are recommended for deck flooring materials to prevent decay. Boards are placed with a gap in between for water to drain out. 2"X6" nominal placed a maximum of 24" on center may be used for decking, or 5/4"X6" nominal placed a maximum of 16" on center.

Required if the finished floor of the deck is greater than 30" above grade. The minimum guardrail height is 36" above finished floor and built to withstand a 200 pound force applied in any direction. The minimum distance between balusters is less than 4" measured either horizontally or vertically.

The maximum step rise is 7 3/4", and the minimum step run is 10". The rise and run distances may not vary by more than 3/8" for the length of the complete run. Handrails are required for stairs having 4 or more risers, serving a single family residence. The handrail must be between 34" and 38" above the nosing of the stair treads.

The proposed deck should not adversely affect natural light from entering these windows. If these windows are necessary for emergency egress (i.e. bedroom windows), then appropriate construction is required to maintain proper distances and escape route.

Electric meter must remain at 5'6" above grade including finished floor of deck.

Proper height of overhead service drop must be maintained:

The meter may need to be moved in some instances.

(Return to top)


Plot Plan Requirements (see a sample plot plan)

1. North Arrow.
2. Property Address.
3. Lot dimensions.
4. Easements and adjoining street name(s).
5. Parking and sidewalk locations.
6. Location of proposed and existing structures including house, detached garages, sheds and the Deck. Show dimensions and distances to property lines and each structure.
7. Location of utility lines inclusive of water, sewer, electric and gas lines if affected by project.
8. Drainage pattern if affected by project.

Structural and Layout Plan View

1 Overall deck dimensions.
2 Dimensions and depth below grade, of footings/caissons.
3 Beam size, span, and bearing locations. (include cantilevers)
4 Post anchor size and spacing between posts.
5 Window, vent and crawl space access size and locations if covered by this deck.

Framing/Architectural Plan

1. Grade and species of all wood framing members.
2. Size, span, and spacing of joists, beams and posts. (include cantilevers)
3. Size and species of decking materials.
4. Bracing details.
5. Finish grade with slope shown.
6. Show dimensions.
7. Location and size of stairs and guardrail and window wells.
8. If involved in this project, show:

a. Plumbing fixtures (hot tubs)
b. Electrical plan including outlets, switches and emergency shutoff location.

See Deck Section

See Detail A, Detail B, Alternate Detail B1, Alternate Detail B2, Detail C

See Handrail Specifications, Handrail Details, Unacceptable Handrails


(Return to top)

Download this Information

IMPORTANT: You MUST have the Adobe Acrobat Reader on your system prior to selecting the report in order to be able to view these files.


Decks and Porches (decks.pdf, 499 KB) Porches y Terrazas Destapados Residenciales (decks_span.pdf, 625 KB)

Deck/Porches Application Use the Residential Remodel/Addition application.



(Return to top)

Last updated: 04/22/10