Decks, Gazebos & Pergolas

Decks - Construction Requirements

The installation of a deck requires:

  • A completed Building Permit Application
  • A drawing of the proposed project that shows detailed compliance with one of the construction methods listed below.
  • A site plan showing your lot, location of all buildings on the lot, and the proposed deck
  • In some cases, subdivision approval is also required (Contact your subdivision representative for more information, our office does not have subdivision representative contact information)

What You Need to Know About Decks

Zoning Requirements

  • Decks up to 3 feet high may extend to within 8 feet of the rear property line.
  • Decks over 3 feet high may not be closer than 24 feet to the rear property line. Side yard setbacks can vary, so please call with questions.
  • If your plans include the installation of a roof over the deck, the distances to the property line are greater.

Construction Requirements

Decks for one or two-family dwellings must be constructed to one of the following standards;


SPS 321.225 Decks. (1) Decks attached to dwellings and any detached decks that serve an exit shall comply with the applicable provisions of subchs. II to X of ch. SPS 321, including all of the following:

(a) Excavation requirements under s. SPS 321.14;

(b) Footing requirements under s. SPS 321.15 (2) (f);

(c) Frost penetration requirements under s. SPS 321.16;

(d) Load requirements under s. SPS 321.02;

(e) Stair, handrail and guard requirements of s. SPS 321.04.

(f) Decay protection requirements of s. SPS 321.10.


SPS 321.225 (2) A deck that complies with the standards in ch. SPS 320-325 Appendix B, and ch. SPS 320-325 Appendix C, if applicable, shall be considered as complying with sub. (1). Meaning, you would follow Appendix B and C exclusively.


Also, the Department of Safety and Professional Services (DSPS) has determined that a deck designed and constructed to the DCA6 standard, (Prescriptive Residential Deck Construction Guide-2012 IRC version by The American Would Council), would be considered code compliant. The decision was based on several factors which included the following:

-Based on prior analysis by the department, the DCA6 standard met or exceeded Wisconsin Uniform Dwelling Code requirements.

-The DCA6 standard is primarily based on NDS standards, which the Department also adopts in SPS 320.24

-Finally, utilizing the DCA6 standard would in fact be considered a form of structural analysis which is accepted under the scope of SPS321.02(2).


A gazebo is a structure with a permanent roof, intended to shed water, its sides could be open or enclosed. This type of structure is typically intended to spend a duration of time in. Our ordinance setback requirements apply to this type of structure and a Building Permit is required.


A pergola is an open sided structure that supports some type of overhead, nominal lumber or other material meant to provide shade. It is not intended as a permanent watershed. This type of structure is typically intended to spend a duration of time in. Our ordinance setback requirements apply to this type of structure. A Building Permit is required only if it will be attached to a building.

Gazebo Sketch