Building Codes

• The size of the deck, distance from the property lines and height of privacy screens are regulated in local codes. Height restrictions, railing regulations and step specifications also apply, and some communities have standards for the design of the structure. Check for requirements for a building permit or design approval, and supply a scale drawing of the deck to help move it through the permit process. Locate utility lines before excavating for posts and footings.
  
  

Deck Design

• Take the lay of the land into account when designing the deck and consider building a multilevel deck for a sloped lot. Break large spaces into smaller units with a mix of social and intimate scales. Assign a function for each unit, such as dining or recreation, guiding circulation with steps, railings and furniture arrangements. Test the proposed layout by putting stakes on the ground and set lawn furniture inside the stakes to get a feel for the dimensions.
  
  

Materials

• Decks are exposed to the elements; if water-and-decay-resistant wood isn't used, it will have to be treated. Pressure-treated wood should be used for the supporting structure, especially the parts that are in contact with soil. The decking may be pressure-treated or made of a different material, such as cedar or redwood, or it can be an untreated wood painted to complement house detailing. Handrails may also be untreated or painted; they're often a striking architectural feature of the deck.
  
  

Structural Design

• Structural members are calculated from the top down; once the decking material is known, the joist spacing is determined. Choose the beam spacing and then the joist size that works with it. For an above-grade deck, posts may also double as posts for the railing, in which case the spacing for those rails is the guide. Local lumber stores may assist with the materials list, or hire an experienced contractor for the work.