OT New home wall thickness

We followed alot of the EnergyStar recommendations. We built with 2x4s. We put foam boards then fiberglass batts over that. My walls are R30, cieling is R50 (blown insulation over batts). We did all the foam board installation and contractor did the batting. We also did the interior wall insulations for noise reduction including the ceiling/floor between upstairs / downstairs. Lots of caulk and weatherseals, including TYVEK. Also used a good latex paint.

Hi-efficiency windows are primarily N and S for maximum natural light without direct sunlight. Our house is extremely tight yet we use the windows for venting as well as screen doors.

Took a little longer to build but I am very pleased. Our electic in the summer runs ~120.00/mo (N. FL) and in the winter ~50.00/mo. for a large home. We heat with wood and propane fireplaces. AC Units are SEER 17. Wanted to go geo-thermal but could not find anyone with sufficient experience (future plans for this using 2 acre fish pond for heat exchange).

We did alot of the sweat equity ourselves which saved us from paying contractor costs i.e. whole home stereo, attics, CAT 5E wired network, dirt work etc. House was truly a collabrative effort as custom builder was preparing for retirement and our house is WAY out in the boonies - permitted some extra time for some of the amenities we are blessed to have.

Check out FOTKI.COM and query for ShepFL. Subscription was just renewed last week.

• Energy Efficient Housing Links

You might also get your utility to pay for part of the extra cost. Alot of Utilitys do that now days.

Me, the new houses are very air tight and feels stuffy. I would add intake air vent(s) at the wall bottom with a damper (for air control) and filter (dust control) on the prevailing wind wall then add a high up exhaust vent towards the cieling on the opposite side again with a damper and filter.

This way you get free cross air ventalation (no fan no utility cost) and better than a window as the air is filtered.

A 6" wall is more structual sound than a 4" wall. Alot of building codes won't allow for a 4" wall if the utility company been pushing the energy savings.

Natural Gas heat is the cheapest. A ground source HP is next as well gives you refrigeration. I think your in too cold of a climate to use a air over HP unit, 20º to 45º. Do not use electric strip heating as it's too costly, typicaly about 8 times the utility cost.

Only by a unit with a scroll compressor as it will last a very long time vs a piston compressor. Never buy a radial compressor for any thing (worthless junk).

T_Bone

You're right it probably is too cold for a heat pump in Southern IL for a heat pump anyway. My brother in law that has one in North Missouri(power company paid for half) and he has to burn wood on really cold days because the system just can't warm the house. Has no problems keeping the house cool though.

Sounds awful expensive for what you were quoted.

A ground source HP can either be wet, uses well water etc:, or dry uses the earth as a heat sink.

Ground temperature doesn't change very much yearly, 50º average 8ft deep, for most of the USA, and is why a GSHP works well and very efficient.

Sizing HP HVAC units is a big problem in the industry. Most units tend to be sized for the refrigeration side and not for the heating side. Some areas due to the radical temperature swings a split or piggy back unit is best.

Alot to consider to spec the correct unit system for a pictular area.

I went to Alaska one time to spec a 50ton refrigeration system in a area that never got above 60º with very little humidity. Thats the gov't at work for you.

T_Bone

You have proposed the minimum insulation amounts.
"DL" spoke of super insulated houses. I have also done considerable reading about them. One home builder in upper New York state builds with R-50 sidewalls and R-90 ceilings. He uses lots of caulking and sealants. The extra money required for the higher R value insulation comes from the homes he builds requiring NO HEATING SYSTEMS.

The normal heat producing activities, such as from the hot water heater, cooking, the heat produced by computers, televisions, lights, provides all heating. The homes are so tight that of course an air-to-air heat exchanger is needed to provide fresh outside air for the home.

While you asked about insulation, I'll throw out some other thoughts too.

Please get a GOOD book on the latest framing techniques. They provide strength while also providing "thermal breaks" to stop the transfer of heat.

Also use the latest recommendations for wind strapping, i.e. roof hold down clips as well as else where.

You spoke of cutting back on windows. Please don't cut back on the south side of the home. For maximum solar gain in the winter, a home needs 10% of the floor square footage in windows.

You owe it to yourself to build properly as this may be a once in a lifetime structure. Saving monthy energy expenditures will help pay the taxes and the mortgage should you have one.

May your building project go swiftly and provide you with a home even more wonderful than anticipated. Cheers.

• Huber Advantech

I think it is great that you can do this.....give it he!!.

Good luck on the project,

Allanj

You are only gonna build it once. Put in the big stuff while you are at it, you won't be sorry.

Allan

Sure could here in Minnesota. If you can afford it today, sure seems to make sense.

--->Paul