When designing a building, architects must strike a balance between form, function and real budget constraints. In addition to the challenge, more and more municipalities are now demanding bird-friendly products, which can increase project costs. Fortunately, architects can minimize the costs associated with bird-safe glass design rules through smart decisions during the planning phase.
Selection of quality bird safe glass
Today, architects have a number of bird-friendly glass options to choose from, with varying qualities and prices. Field studies and tunnel tests show that the most efficient design solutions comply with 2 “by 4” to reign. This rule requires that markers be no more than two inches apart on a horizontal axis or four inches apart on a vertical axis.
These dimensions are shorter from top to bottom than most birds in flight and narrower than their wingspans. Even though the birds don’t see the glass itself, they see the markers as obstacles very close together. As a result, the birds do not try to fly through the glass.
Extensive testing has shown that the most effective markers are placed on the outer surface of the outboard lite (surface # 1). Surface n ° 1 is important because it is the only one that is always visible, whatever the lighting conditions.
Glass may appear transparent, reflective, or very dark, depending on the lighting conditions. For this reason, markers placed on interior surfaces are much less noticeable in certain lighting conditions and birds will not see them. Unfortunately, many bird-friendly solutions fall into this category. This is not the case for acid-etched glass.
The acid etching remains permanently on the glass surface and, unlike sintered ceramic markers, does not add additional layers which can fade or wear away over time. Since they are embedded in the glass, acid etched markers will not degrade or lose their effect, even when exposed to the elements. However, the acid etching is applied at the factory to the glass sheets, not to the cut-to-size openings. Without proper window design planning, a significant amount of the stock sheet can be wasted. The key is to maximize the usable cuts from each leaf. Here are some bird safe glass design guidelines to achieve this.
Optimize the cut
Walker produces bird-safe 96 “x 130” sheets of glass with 1 “of waste on each edge. As a result, the usable dimensions of each sheet are approximately 94” x 128 “. To get the most benefit Starting from glass, manufacturers enter all required glass sizes into an optimization program that defines the best cutting sequence for each sheet.
If the architect designs windows (less framing) that are 47 “wide or narrower, the manufacturer will be able to cut two or more sheets of glass side by side from the sheet. This minimizes the amount of waste. On the other hand, if the panes are wider than 47 “, then the manufacturer will remove only one pane and the rest of the glass will go to the recycling bin.
Keeping the 94 “x 128” limit in mind, the architect can use glass most efficiently and help keep the price of the project low.
Walker also produces bird-friendly etched glass sheets measuring 72 “x 130” or 84 “x 130” (usable 70 “x 128” or 82 “x 128”). Depending on the size of the window, these smaller sizes may be more cost effective than a full 96 “x 130” sheet.
Designing with Templates: Best Practices
Bird-friendly glass designs present a second consideration: the direction of the pattern. The models fall into two categories. Non-directional patterns look the same when rotated 90 °, while directional patterns look different when rotated. A linear stripe pattern is an example of a directional pattern.
If the architect specifies a pattern with lines spaced two inches apart horizontally, the maker should cut all sheets of glass with the pattern horizontal. Even if there is enough glass to produce two sheets by rotating the sheet, it is a waste because the pattern will not work in the intended direction. On the other hand, if the architect specifies a non-directional dot pattern based on a square grid, the etched glass sheet can be rotated to produce the maximum number of sheets.
Walker Glass offers a total of eleven designs in its AviProtek® bird-friendly glass line. Of these, four are directional and seven are non-directional.
Tax responsibility and green design are important considerations in any project. It can be difficult to balance these two factors, but some smart advance planning can certainly help. Protecting birds by choosing designs that follow the 2 ″ x 4 ″ rule applied to surface # 1 is by far the smartest design approach.
First, getting the most out of each sheet of glass by optimizing window sizes early in the design process ensures that budgets are kept. Then, for even greater efficiency, select a multi-directional pattern for your bird-friendly windows so that your maker can rotate the glass to fit more cuts in each sheet. Keeping these design rules in mind, architects will stay on budget and avoid collisions with birds.