affordable central vacuum system

In any green building project, indoor air quality is a primary concern. I don't know about you, but I do not want to save the planet at the expense of my lungs. This site has some interesting information about IAQ. INSPECTAPEDIA
He says, "Central Vacuum Systems, if properly installed, vent directly outside, avoiding the issue of stirring up indoor particles during house cleaning. It's a more-costly but great idea. Just be sure the vac is properly vented. I've inspected homes at which the central vacuum machine was in a laundry room or basement, venting its dust back into the home."

I would have to disagree with him about the central vacuum systems being more costly. A good HEPA vacuum runs between five and a thousand hundred dollars. We have an Imperium central vacuum that takes a high quality HEPA bag on sale for $249. Even if you add attachments, pipe, fittings, etc., you can still be in the ball park of a good HEPA vacuum cleaner.
Check out the Imperium CV280

In your green building project don't pass on a central vacuum system because you think it is too expensive, check out the options that are available. A central vacuum system is the only 100% dust free way to clean.