Ah, something where I actually have experience (being a non-electrician guest here).
More than half of internet users do not upgrade their browsers. Among open source development geeks, most do. So it is not surprising that most of these web site designs require the newest browsers to work.
When choosing a web site design for your business, consider what your customer base and market is. If this includes people who less likely or unlikely to be upgrading their browsers to the latest version, and especially if they are using several years old computer software, you might want to choose the minimal requirements, even if it means a less sophisticated or glitzy web site. In such cases, also avoid using things like Flash (or if you do use it, use it in a way that anyone who can't see it can still get all your content by some means).
Glitzy flashy web sites are generally for art and media businesses. I'd expect such things on a web site for a movie or a rock band. But if I'm looking for an electrician/EC, that kind of thing actually puts me off. I prefer information; get to the point and tell me what you do and how well you can serve my needs.
Of course it is till possible, with some work, to be fairly fancy using minimal formats and standards. The following web site I created in one afternoon works quite well on a range of browsers all the way back to Netscape version 3 and Explorer version 3. http://www.linuxhomepage.com/
The above is meant only to illustrate web site features. It is not my business site; it is a hobby site.