HVAC. Air likes the path of least resistance. While you can move ducting, plan to move it so that the new line has as few bends and turns as possible. For example, moving a supply vent to the edge of a wall from the middle is possible as long as you have a straight chase all the way through your wall system from furnace to vent. And, while you may be inclined to simply eliminate a cold air return, that's a bad idea. First you'll make your furnace work harder to get make-up air (look at it like breathing through a straw) and second, you'll probably shorten the life of the unit, never mind affecting how well your space is conditioned.If you come across a job where you're inclined to move the refrigerant lines, don't. You need special equipment for that and an HVAC specialist to do the work.
Electrical. Wire might be the easiest mechanical to move. The key is to either run new line (while eliminating the old) or to correctly place any junctions (splices in the line.) If that guy down the street who knows a lot about houses tells you that you can bury a junction in the wall, he's what experts call "wrong." Any time you junction a wire, you need to have access to it. Proper ways to junction a wire, however, are many: in a light or plug, for example. Or you can simply put the wire in a box and cover it with a blank face plate. You might also be able to turn the box around and add a plug to an adjacent room.
And for when the real world outsmarts code, there is a code-approved option for splicing wires in walls. It's a non-metallic union made by NSI Industries. Where and when to use such a device is, in my opinion, the bailiwick of an experienced electrician.
If you have old-fashioned knob-and-tube wiring (so called because the wire is surface-mounted to framing with a ceramic knob; when the wire passes through framing it is sleeved with a ceramic tube) you're really gonna want your electrician, and, according to my electrician Bob King, an old one who has worked with knob and tube before. See, back in the old days there was little rhyme or reason to how electricians wired houses, and you could have several rooms being fed by a single line. It takes someone with serious know-how to diagnose and cure knob-and-tube-itis.
Pipe. Plumbing supply lines, drains and vents are also moveable, to a point. The key is to have a chase(s) for them all to live in. If that chase is on an outside wall and you live where it snows, most plumbers would call it a "bad idea." Water has a tendency to freeze and, in so doing, burst pipes. Read: disaster. Ideally, water pipes should run in interior walls as much as possible. Check with your plumber.
As for eliminating vents (the pipes that run up through the house and exit through the roof) — well, that's also a bad idea. Your plumbing system needs its vents to breathe so that water can drain properly. While it may not seem like a vent does much, it really is there for a reason.
And that's the point: All this stuff in your walls is there for a reason and acts as a system, which leads me to the punchline: Knowing what you're dealing with ahead of time gives you the most information to make the best decision for your patient — and end up with the best results, whether that comes via calling in the specialist (sub-contractors) or deciding to make other choices with the bigger picture of your remodeling operation.
Mark Clement is a remodeler and author of The Carpenter’s Notebook and The Kid’s Carpenter’s Workbook, Fun Family Projects! Find out more at www.TheCarpentersNotebook.com.
