Final answer:
The earliest form of load-bearing construction is the post-and-lintel method. It comprises vertical posts supporting horizontal beams, allowing for the creation of load-bearing structures with open spaces.
Step-by-step explanation:
One of the earliest forms of load-bearing construction is the post-and-lintel method of construction. This technique involves placing vertical posts at intervals and spanning beams across the top as lintels, which helps to distribute the weight and allows for open spaces between the posts. Specific examples of post-and-lintel can be seen in historical structures such as Stonehenge, which dates back to approximately 3000 BCE. Load-bearing walls made from materials such as wood, stone, or brick, had to be thick and strong enough to support the weight of the roof and any additional upper stories. Italian stave churches and Mesopotamian architectures also utilized variations of post-and-lintel construction to create larger windows and doorways, a feature that wasn't possible with traditional load-bearing walls due to their inability to support such openings without collapsing.