Which of the following may NOT be insured under a builder's risk coverage form?

Builder's risk coverage is specifically designed to cover buildings under construction, materials being used for the construction, and certain aspects of the project site. The correct choice for what may not be insured under a builder's risk coverage form is existing structures on the property. This is because builder's risk coverage primarily focuses on the construction process itself, rather than providing coverage for properties that are not part of the project currently underway.

While builder's equipment may be covered under a different type of policy, it generally would not fall under the standard parameters of a builder's risk policy. Therefore, distinguishing between what is part of the construction project and what exists prior to or independently of that project is vital in determining coverage. Existing structures do not receive coverage under builder's risk policies since these structures are not being constructed or renovated as part of the current project; they are simply present on the site.

On the other hand, the building being constructed, along with materials stored on site for that construction, are central to builder's risk coverage, fulfilling the purpose of protecting against risks associated with a building project.