A spec builder is a property developer who constructs homes on speculation or speculation houses, which means the builder puts up the property without having a buyer in place. Some common synonyms for a spec builder may include a speculator, developer, property promoter, home builder, or construction company. Other similar terms might include a speculative builder, a tract home builder, or even a mass production builder. In some cases, these terms may be interchangeable, and the specific word used may depend on the context in which it is applied. However, they all refer to professionals who specialize in creating property or houses for sale without a buyer in place.