A fixture or a bulb can cause the energy plan to go over budget. Is the implication that you are using the wrong product or that you are redesigning the energy grid? Suppose you install the energy inefficient product and it holds up commissioning and the Certificate of Occupancy. Is the claim against the product, the completed operation or the professional design?
Every product has been designed for a purpose. If you install that product for that purpose, and your installation is per product specifications, defects are considered product liabilities.
The architect and engineer draw plans and specify products to be used. If you follow those plans and install those products, your work will be a completed operation.
If the plan calls for your specialty to design some aspect of the building, you will have a design liability.
The grey areas concern modifications to the product or design outside the scope of work.
Completed operations insurance does not cover design liability except in very minor cases.
Consider loss control for these situations. Either avoid them, wise choice, or purchase some professional liability insurance for design professionals, and get an architect or engineer stamp.
With energy codes, LEEDS certifications, environmental issues, and historically standard conditions to meet, alterations to any aspect of the project drawings can have devastating effects to the building commissioning.
Be hyper cautious when altering plans or using replacement products. Request a substitution change order if products are unfindable or at least the specifications are unmatchable. Suggest design changes in writing in change orders, even the most minor changes. Your not out to be thorough, not difficult.