Building a deck or patio is a great way to improve the property value of your home. However, the cost can still vary greatly depending on the features you want to include. The average cost to build a deck is around $30 per square foot. Most homeowners spend somewhere between $1200 to as much as $10,000. An entry-level deck with basic materials can cost as little as $25 per square foot but a multi-level deck with premium features and materials can cost around $35 per square foot.