The correct answer assumes the architect knows the specification of the existing glazing, in which case a proprietary specification would be appropriate. In reality though, that information is often not available, so a descriptive specification would be the more appropriate choice for this application.
Either way, the question shouldn’t leave room for assumptions.
@ema.markovska thanks for writing in! That’s a fair observation. For this question, the intent is to test which specification type would ensure the exact same product is selected. The word “identical” is the key clue pointing to a proprietary specification, since it can identify a specific manufacturer and product. In practice, if the existing product could not be identified, a descriptive specification may be necessary to achieve the closest match.
Hope this helps!
Kiara Galicinao, AIA, NCARB
Product Coordinator
Black Spectacles