Tri State in Carderock MD is a real quarry and has lots of other stones from elsewhere. You weigh your car before and after to determine the weight. Price on local stone is very good. They usually have huge trucks coming in and out so it might be a good idea to call them first to find out when is the best time for us little folks to come. Here is a link that might be useful: Tri State Stone

Barton Springs Nursery on Bee Caves Road has Metro Mix in large bags. I don'y know if it is "360". I buy this metro mix to as a sterile mix for seed starter . I combine it with other things to make different things like rooting medium, etc.. If you haven't been to Barton Springs nursery, it is worth a trip. Great nursery.

Its common for the egr passage to plug up inside the intake manifold on those. That's just one possible reason for the code 51. The way the system works is during a deceleration the PCM monitors the map sensor signal, which would be reporting a very high vacuum (low manifold pressure), and while its doing that, the PCM commands the egr valve to open. By opening the egr valve the manifold pressure should increase (lose vacuum). The greater the change in the readings, the more egr flow that is capable of occurring. Little to no change indicates the egr system isn't working and the cause needs to be found. BTW parts stores sell thousands of PCV valves every year simply because people buy them and replace them. I don't think I average finding more than two bad valves a year. Now that could be in part because people like to throw parts at the cars instead of taking it to a pro in attempt to save money. The two or so that I find bad are actually situations where someone has installed the wrong calibration valve, and it ends up causing a problem.

Hi, Thanks very much for your responses. - Everyone I've spoken with, and you've confirmed, that one zone per floor makes sense. If I'm missing anything else about "zones", please let me know! - How much should it cost to go from 2 zones to 4? - We are definitely going to put in all new ductwork. Is there anything here that I should be aware about or ask for? Any sites (besides GW) to get more knowledge on this area so I can ensure we get the ducts sized properly? - Good comments on getting more info on the geo wells, piping, etc. Will do. - Can I get a Manual J done even if the house is under construction? Framing is almost done, but the exterior work is not complete, and so it's open to the elements right now. - Yes, we have a natural gas furnace and electric AC in the house. It appears that a NG furnace was installed in 2007. The unit is a Lennox Signature Collection, model CX34-62D-6F. We also have an electric hot water heater, AO Smith ProMax Plus, model FCG 75 300. Does it make sense to re-use these or upgrade? Obviously, the furnace will be out if we go with geo. - Here's a summary of our NG and electricity rates. I hope I'm doing this correctly -- taking the bill amount and dividing by the energy used. Some months may need to be taken out because the numbers are too high/low. Please note that we have not lived in the house, so this is what we were paying for several months before construction commenced. So I would expect actual usage, and thus our bills, to be higher, but I guess that the cost per unit would be somewhat proportional. Natural Gas Monthly Charge / Therms Used / All-In Cost Per Therm $18.06 / 5.1 / $3.54 $16.76 / 5.1 / $3.29 $51.90 / 32.5 / $1.60 $78.53 / 57.7 / $1.36 $339.62 / 314.7 / $1.08 $362.71 / 321.1 / $1.13 $184.41 / 154.8 / $1.19 $81.98 / 60.4 / $1.36 $66.62 / 47.4 / $1.41 $18.45 / 7.1 / $2.60 $16.18 / 5.1 / $3.17 $1.97 average Electricity Monthly Charge / KWH Used / All-In Cost Per KWH $285.18 / 1757 / $0.16 $137.36 / 786 / $0.17 $77.44 / 416 / $0.19 $57.91 / 316 / $0.18 $66.29 / 382 / $0.17 $86.87 / 524 / $0.17 $61.02 / 341 / $0.18 $24.50 / 76 / $0.32 $25.22 / 80 / $0.32 $38.34 / 73 / $0.53 $21.23 / 53 / $0.40 $32.62 / 140 / $0.23 $0.25 average - It must not be code on my state (MD) to have each floor zoned. Our bids have been for two zones (on per system, one system covering basement and first floor, second system covering second and third floors), or for four zones (running off two systems). - Thanks for the heads up on the tax credits. My husband is tracking these, so I'll make sure he knows this. - The addition is on a loggia, not crawl space. So the basement is a walk-out basement, and the loggia will in effect extend the basement, and then the kitchen/family room addition will be above this, and our master bedroom addition above that. It's at the back of the house. Here's an early photo so you get the idea. The house is brick, and the addition will be part brick, part clapboard. - I am trying to learn what an HRV is, so am looking into this. - If it's not a good idea to go with spray foam insulation, let me know! Thanks for the info on what type would be good. - More thoughts on what system to go with, pricing, etc.?? THANKS AGAIN!!