Deck building
in Harrisonville

Most decks do. Harrisonville adopted the 2018 International Residential Code as its building code for one- and two-family homes in Section 500.070 of the city code, and its local amendments in Section 500.080 leave the code's deck exemption unchanged. Under that exemption, a deck doesn't need a permit only if it meets all four conditions: it's no larger than 200 square feet, it's no more than 30 inches above grade at any point, it isn't attached to the house, and it doesn't serve the exit door the code requires for the home.

Miss any one of those and the deck needs a permit. In practice, that means a deck attached to the house, a deck high enough to need a guard, or a deck that the main back door steps out onto is permit work in Harrisonville, whatever its size. A freestanding platform out in the yard is the kind of deck the exemption was written for.

The exemption covers the permit only. The 2018 IRC states that exempt work still has to comply with the code, so an exempt deck is built to the same footing, framing and fastening rules as a permitted one. Harrisonville's amendments name the city's Community Development Department as the code enforcement agency, and permits for property inside the city limits are issued through City Hall.

Every jurisdiction that adopts the IRC fills in a table of local design conditions, and Harrisonville's values appear in its amendments to Table R301.2(1). Several of them apply directly to a deck:

Frost line depth: 36 inches

Deck footings bear below this depth so freezing soil can't lift them.

Weathering: severe

This rating governs concrete durability requirements, which matters for footings exposed to repeated freeze and thaw.

Termite: moderate to heavy

Wood near the ground needs protection from decay and termites, so posts and framing are pressure-treated lumber rated for their exposure, and lumber in contact with the ground is rated for ground contact.

Ground snow load: 20 pounds per square foot

This figure matters most when a roof is added over a deck, since the roof's posts, beams and footings have to carry it.

Harrisonville's adoption also includes several of the code's optional appendices, among them Appendix H, which covers patio covers. A roof over a Harrisonville deck is reviewed with those structural values in mind, and our covered deck page explains how the roof's loads change the deck below it.

The ordinance also sets the standards the commission applies. Two apply directly to a deck. New additions and alterations should be compatible with the size, scale, color, material and character of the property and its surroundings. And wherever possible, additions should be built so that if they were removed later, the essential form and integrity of the house would remain unimpaired.

For a deck, those standards point to specific design choices: a deck that stays below the scale of the house, railing and decking colors that sit quietly against the original materials, and an attachment that can be undone without damaging historic siding or trim. A freestanding deck, carried on its own beam and posts beside the house, meets the second standard more easily than one bolted to the wall.

We're a locally owned, licensed and insured company building, repairing and replacing decks in Harrisonville and across the Kansas City metro. As a deck builder in Harrisonville, we start each project from three facts: city or county jurisdiction, whether the property is designated, and how the house can carry the deck.

When an older deck is still structurally sound, deck repair addresses the damaged parts and deck resurfacing replaces the walking surface on the existing frame. A deck where nothing stands today starts with new deck construction. On a designated property, the choice between wood decking and composite decking is also a question of color and texture next to the house. Railings come under the guard rules on our deck railing page, and our deck stairs page covers riser and tread dimensions.