How to define vision glazing

Sharlene, You state that the occupants should still be able to see outside. First i would confirm that they can before considering this product. I would say based upon the intent of this credit that an obscurred view is not acceptable. I would refer you to read the Heschong and Mahone study referenced in the Reference Guide to get a better understanding about the intent of the credit. Using the standards in the study as basis as to what an acceptable view is, i would say anything less than clear glass would not be acceptable. I looked at V2.2 and 2009 LEED Interpretations and there is nothing related to this. However, the rulings in two interpretations state there needs to be a quality of view to meet the intent. So based on that statement, is it really a quality view. If you were to attempt this, i highly suggest you take pictures of what the view would look like with this product.

A picture is a very good idea. A highly reflective outside finish could still provide the inside occupant with a unobscurred view.

It’s been just over a year since the last comment, and I’m wondering if there have been any more developments on this thread. Our office has a project that would have a metal scrim set off 6” from the glazing in the vision zone primarily for security purposes. The scrim will have 20% openness.

Heather, They are pretty strict on this credit with items that obscure the view even a little bit. A 20% openness factor is far too small. Also, setting a screen any amount of distance off of a window makes it harder to see through than not. (Think of riding a city bus with advertising on the outside of the window that you can still see out of from the inside of the bus) So this increases for every extra distance the occupants are away from the window. It sounds silly but I would think even a 95% openness factor right up against the window would be questionable. You can't get exceptions for this credit due to security issues, you just have to find a different credit. Or if you can prove your point using photographs, go for it.

Are the reviewers now scrutinizing the % of view? There is an innovation part of this credit that is the proper place for that. A blockage of 80% won't let your eye merge an outdoor image together well. A fine-screen blockage of 30%--typical for residential window screens--darkens the outdoor view slightly, but your eye sees a well defined, and full, image. The examples in the LEED Reference Guide--incorrectly, in my opinion--show a large wall between windows as not being discounted from the view calculations. Refer to RG Figure 3. About 60% of the view is blocked by a solid wall. If, views are being discounted for screens, breeze soleil, and similar, then why not penalize dark gray glazing? If the Reference Guide conflicts with what the reviewers are being told to look for, the correct answer is to correct the requirements for LEED v4. The correct answer is not to make any changes until LEED v4.