If you decide to attach the cords at the bottom, here are a few methods.

We prefer to have the bottoms of the cords hang free, but sometimes this is impractical. There are many different methods that can be used to secure the cords at the bottom. Here are just a few:

"At the higher elevations of Smokies where I built a log home, WIND is a daily occurrence. I have installed Zen Wind Curtains [Acopian BirdSavers] on all my large, vulnerable windows. However, gusts of wind cause the vertical paracords to get seriously tangled. 
Finally, on the high windows requiring a 30-ft extension ladder for any window work, I CAME UP WITH A WORKABLE SOLUTION: I knotted the bottom end of each string and secured it loosely (slightly above the knot) with a medium-sized U-tack [see photos below]. The U-tacks allow the paracords to flutter in the wind but keeps them from getting tangled up with each other. (I test each string to make sure the U-tack is not too tight.)
This is a godsend that keeps me (age 71) off tall ladders. And even on the windiest days and nights in the mountains the windows are protected but remain untangled!! 
In six months I haven't had a single bird crash!"
Dr. Ellen K. Rudolph
Great Smoky Mountains




To keep the cords from ‘blowing in the wind’ take some light weight fishing line and about three inches or so from the bottom of the BirdSavers cords, attach one end of the fishing line to the window frame. Then simply wrap the fishing line around the first cord, then move to the next BirdSavers cord and wrap it around that cord, then wrap it around the next BirdSavers cord until all the BirdSavers cords are ‘ensnared’. Then attach the other end of the fishing line to the window frame on the other side. It sounds complicated, but it’s rather simple. And it does work.

If the structure beside the glass is very rough (like brick, stucco, and some stone) the individual cords can get "hung up" on that material next to the glass. A simple way to prevent this from happening is to use a piece of monofilament to contain the paracord in front of the glass. The monofilament is attached to the window frame on each side of the glass as in the photos below. The cords can still move around with the wind, but they can't quite reach the rough surface beside the glass.



One continuous piece of paracord runs from the top to the bottom and then back to the top, as shown in the photos below, sent by Ralph Sanchez. He tells his story:

Three years ago I built a two story Greenhouse with 22 large windows collected over a year from Crag’s List. After I had started to install the second level of windows on the front of the greenhouse I stopped for lunch and when I returned to the yard I found two small birds lying on the ground dead in front of the greenhouse, it took me a minute to figure out that they had flown into the crystal clean windows I had just put up. I felt terrible and realized there was no way I could complete my project if I would be picking up dead birds every day or two. So I immediately put a tarp over the front of the greenhouse to prevent any more fatalities, since I also had many bird feeders in the yard.

I decided to search the internet to see if there were any solutions available out there. I came across a few ideas but this one seemed to be the least expensive for such a large area and was said to be 95% effective. Sounded good to me. So I read the DIY instructions and ordered 1000ft of Paracord online and got the eye hooks from HDepot. The total price was about $150 plus 5 hrs extra work, but I felt it was a good trade for all the birds that would survive all the years that the greenhouse would be up.

And to my surprise I have never had another fatality in the last 3 years. So in my case it has been 100% effective in saving the lives of our feather friends.

---- Ralph Sanchez  Anchorage , Alaska




Whatever you are using for the top horizontal support for your Acopian BirdSavers, use this same support to tie-down the bottom. In the photo below from Nick and Teri Nichols of Olympia, Washington they used small clothing hanger poles and end anchors. Nick says you can easily remove the hanger poles to clean the windows.