We want this site to be usable by everyone, including people who use a screen reader, navigate by keyboard only, or need low-vision support. Our target is the Web Content Accessibility Guidelines (WCAG) 2.1 Level AA.
Every page on this site is plain HTML. You can read all of it with JavaScript turned off; scripting is only used to enhance the site, never as the only way to reach information or to contact us.
If any part of this site is hard to use with your assistive technology, or you cannot reach us, please tell us through the contact page or call the number on that page and we will fix it.
Known limitations: some older articles show plans and diagrams as images, with a short description rather than every measurement in the text. If you need those details another way, tell us.
Last reviewed: 2026-11-01