Proceedings of: Workshop on Improving Building Design for Persons with Low Vision
Mark J. Mazz, AIA: Architectural Consultant on Accessibility
Introduction
My presentation is coming at it from a different angle, different direction (slide 1). I don’t design buildings anymore because I like being self-employed without employees. And what I find that I do best is defining what is required for accessibility, particularly with the ADA or the Fair Housing Act, or even the Architectural Barriers Act.
Quality Assurance
Standards vs. Standard of Care
[T]he easiest thing to do to tell an architect or a builder they did something wrong is point to the standard and say: This is what you’re supposed to do; this is what you didn’t do.
When there’s not a clearly defined standard, the next thing you go to is what is the “standard of care”?
And if you have design criteria that says you shall not produce glare, and call that a “performance standard,” it also becomes something that architects have to do as part of their standard of care; and therefore that’s the level at which they’re liable to.
Measurable Design Criteria
So, I get worried when things start getting written down, if they’re not clear and if they’re not measurable. Performance-based [design] is a great way to talk about stuff, but it is a very difficult way to prove that you – or convince a judge or a jury that you did what you were supposed to do and you didn’t do anything wrong.
Daylighting and Architectural Photography
Residential Example (slide 2)
With that, moving into a few images that I wanted to show, on this first slide (slide 2) you can tell it wasn’t taken by an architect because the base isn’t precisely centered on the table. The reason I’m showing this photo is, first of all, when architects or anybody taking architectural photography tries to show daylight, the easiest way they convince people they’ve got beautiful daylight coming in is they show the contrasting shadows that hit the floor and hit the walls and stuff and see the light that’s coming in from outside.
You don’t see the light sources here. It’s coming in from third-story windows above. There is no artificial light in this space. I believe it’s coming in from all four walls and from up above. It’s an interior room. And also there’s borrowed light coming in from the outside, from the covered porch outside. But by having that much nice diffused light coming in, it sort of balances out some of the direct light that’s coming in from the porch behind. You do have shadows. That’s how you can tell the base is round and not flat. You see it start here in the area closer to the camera lens. And it just – it looks nice. It’s a wonderful space to be in. I highly recommend it.
Ultimate Daylight (slide 3)
Here you’ve got the ultimate daylight, because you’re outside (slide 3). And it’s a place that, if you’ve got teenage boys who want to see lava flow, it’s a great place to go. However, you really can’t make it a family event if your wife has low vision, because there’s not enough contrast going on with the black surface, it’s not a predictable surface, and walking is a nightmare. Consequently, the boys didn’t get to see the lava. We had to stop short because they were there for two hours and only walking about a quarter of a mile. It was just too much for all of us to bear. But here again, daylight is a great thing, but it doesn’t always solve all the problems that are going on in the area.
Public Space Example (slide 4)
And the third one (slide 4), which I don’t know if this would be a space that you all would agree with me – I think is an absolutely delightful space. What’s hard is, it’s the C terminal at the National Airport. You have light coming in from two major walls; one’s east, one’s west. The east wall is probably 30 feet high with the sun coming in. You have daylight coming through skylights above. You have a ceiling that helps diffuse the light as it comes through. And then you have more borrowed light coming in from the west side.
Again, when architects try and take photographs of this space – this isn’t mine; I just grabbed it off a website – they love to show the shadow lines and how all the natural light comes in. But it’s a space that, when you walk through you can feel the colors, you feel the size of it, and everything seems to work well.
Again, maybe my eyes are still younger than the eyes that start having trouble dealing with glare and stuff, but daylight is a good thing to incorporate. And the more daylight, the better, because you can deal with more colors and the contrasting issue does not become as severe, and the glare isn’t as severe if you bring it in well.
Some Design Guidance for Daylighting
Some of the things that I learned 30 years ago in school are:
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Don’t bring daylight in on one wall; try and bring it in from more than one direction. It takes advantage of the fact that the sun is doing different things outside, and it balances out the one-source issue of bringing it through one wall. It may be more difficult in office buildings, particularly when you have a 10-foot floor-to-floor height in Washington, D.C. But you get the interplay with the colors.
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You have to still deal with glare by diffusing the light when it comes in. Things work out better that way.
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Shadows are not a bad thing. Shadows are very good for a lot of aspects of things. And yesterday, listening to stuff, I got the sense that shadows were being considered a bad idea. But you don’t see corners if you don’t have shadows. As an example, in this dark corner over here [pointing in the room], you can tell you have a corner there because one side is almost in full shadow, even though you have ambient light hitting it. That’s how we know there’s a line there that points in a direction.
Another example would be what I commented yesterday, that I did not see the curve in the one slide that Fred showed. It’s a good idea. It helps create vocabulary, that when you see that stripe of darker tile, of darker brick, that there’s going to be a stepdown at that point. But visually, the photo cuts off the ends of it where you can see the actual step down. And depending on the clarity of the photo, you can’t really see that, because there isn’t a shadow line showing the top edge, the visual cue that’s used by quite a few people.
Now, granted, if I was talking to somebody, out of the corner of my eye I would assume there’s a step there because of the darkness. And when you start creating the vocabulary of using a dark strip against a light strip as a step, it’s something you have to be mindful of other areas, too, where you’re just doing some landscaping details and you want to either accentuate the entrance to a building, not using a step of any kind because of dark versus light. You may start creating images. If the vocabulary becomes too strong and too consistent everywhere, it can create that image that you’ve got a step there, and you don’t.
This is something that I see. It gets confusing when people are trying to do things to denote certain areas, but then all of a sudden you start seeing steps. The classic example, where Bob mentioned about the carpet runner upstairs stopping before the end of the step, is something that should be just a visual faux pas for any architect or any designer that they shouldn’t do, because they know that’s a natural tendency [stepping] point.
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The shape of the ceilings can make a big difference as well, how you bring the light in, how you treat the lights so that you have ambient light throughout the room. Fred’s example of Metro: there’s a perfect one showing how you’re never going to be able to solve the problem down there because of the coffered ceilings. How much light would you have to bring in to make that happen? This is a little off the topic.
Measurability is a Major Issue
The other thing of dealing with measurability is, if you’re dealing with light levels in a room, you try and measure the lumens or the foot-candles on the surface of your desk. That can be done. You know, when you’re bringing daylight and stuff, you can bring the light levels up high enough at that point.
But I’m unaware of a way that you can actually measure the light in such a way that you take care of glare issues or some other measurement that can be used and incorporated into the energy guidelines to get at the issues of dealing with glare as Tom pointed out. It’s a big issue. I mean, you can get the 50 foot-candles on the desktop, but you don’t necessarily get at glare in a useful fashion. Thank you.
Comment by Tom Williams: When we’re talking about the 50 foot-candles in office space, some information is out there about the amount of foot-candles that are produced outside. The sun provides about 7 (thousand) to 10,000 foot-candles. So you’re really damping down when you talk about task lighting and working inside a closed environment. There’s a huge difference. The light is free outside. Trying to channel that light so that it allows us to work comfortably inside, that’s a huge challenge.
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