Q: If a renovator is only reimbursed for materials, would that be considered compensation?

No.  Compensation includes pay for work performed, such as that paid to contractors and subcontractors; wages, such as those paid to employees of contractors, building owners, property...

No.  Compensation includes pay for work performed, such as that paid to contractors and subcontractors; wages, such as those paid to employees of contractors, building owners, property management companies, child-occupied facility operators, State and local government agencies, and non-profits; and rent for target housing or public or commercial building space.  Reimbursement for the cost of materials is not compensation.