Well here's what we have here, we had two oil heaters installed for our greenhouse in the fall and they won't pass inspection because of the clearance of the vent pipe through the wall which is basically going theough a piece of sheetmetal mounted on 2x4 framing. It's not fancy but this is what we have done for years and what every nursery does in town. I was told to get the vent piping that would make us meet the code requirements would be $800 per heater, a lil steep and moving the framing out would require almost a 4' square piece of sheet metal for each heater, not good when you want to let in as much sunlight as posible. Well, anyway the calls to the building department to try to resolve this hasn't really helped and attempts to get our contractor back out..... well, he doesn't want to do it to make a point. He made a point, won't be doing any more work here. We just want it finished, we have enough handy people here that do most of the construction, electrical and plumbing work, the only thing we do sub out out is the heating work (the only thing that didn't pass inspection. Figuring we can get someone here to build the heat shields....just need an idea of what material we would need an maybe a place to find a template or something to guide us along.