What drives the decision
Identify IGU construction and coating location where possible before requesting final proposals.
What changes the budget
Compatibility restrictions or warranty review can change the shortlist of acceptable products.
Operations and lifecycle
Future IGU replacement normally means replacing the film on that unit too.
Planning boundary
Use film and glazing manufacturer compatibility guidance for the exact IGU.
Educational planning only. Actual construction, code compliance, regulated systems, hazardous materials and safety-critical work require qualified professionals and current local requirements.