Final answer:
Speculative construction is when builders start constructing homes without secured buyers, with hopes to sell during or after completion. It contrasts with contracted and customized construction, where buyers are involved before or during the building process.
Step-by-step explanation:
The type of construction referred to as beginning construction on homes without having secured any buyers is known as speculative construction. This practice involves builders starting the construction of homes with the speculation that buyers will be found later on, often during the construction process or after the homes are completed. This is different from contracted construction, where a contract is in place with a buyer before construction begins, or customized construction, which is tailored to the specific desires of a buyer who has already committed to the purchase.
During the construction of a building, work begins with the foundation and proceeds in a systematic fashion towards the highest level. It's a step-by-step process that starts at the bottom and relies on each level being completed before moving to the next, which ensures structural integrity and proper progression.