Wiring In New Construction

Can you use CAT5 in new house low voltage communication wiring and do you have to do home runs?  The answers are maybe but probably not for the former and you'll regret it if you don't have it installed as at least one home run - depending upon the size of this new construction.

The NEC or NFPA 70 addresses the fire violation risk in requiring a 2" separation minimum. Which is a convenient out but the fact is that industry standards are 4" and the contractors in the know will separate the electric light and power from the communications conductors by 6"-12". 

If your communications wiring isn't originally installed in a Home Run style, you could regret it later.

Remember one important thing about CAT5 - after 100' you're going to lose speed (voltage drop) and this will have a profund impact upon equipment, especially your computer if wired (which I prefer) and not wireless. So consider CAT5e or CAT6.

I know it is confusing but whatever you do, have your communications wiring diagram drawn up by a professional and preferably not the contractor.

There are some great discussions and articles which you should read. Although some are older, the NEC hasn't really changed that much in this regard.

http://www.xsvtoys.net/sw2_planning1.html

A long discussion so read all 4 pages even though it goes off-topic a bit: http://www.dslreports.com/forum/r25361166-Can-you-run-CAT5-wiring-and-power-wiring-together-

I think you'll appreciate this one http://www.fadden.com/homewiring/

And this one while older really lays it out: http://www.9thtee.com/homewiring.htm

Do not try to economize in this area because the functionality of entire aspects of this system are going to be behind drywall in new construction. That doesn't mean that you have to overkill. What it does mean is that designing a system for this new construction - and I am assuming a house - means considering future needs and uses of this system.