Brick probably has a slight edge in terms of energy efficiency but not by much. The insulation in the wall come from what is underneath the outside sheathing. Check with your local housing department to see what is the minumum and recommnded insulation factors and then the house should meet that standard.If you are buying an existing house, some rules of thumb are that 6 inch walls can contain up to R 20 whereas 4 inch walls contain only R12. The more insulation, the greater the initial costs, but the less energy the house will consume. It's a trade off and depends what part of the country you are in as to what makes sense. I am on the frozen prairies so our minimum now is R20. The overall tightness of the structure and window numbers, placement and energy efficiency all have an important bearing. Check out the Dept of Energy or housing for more information on how to assess this.

Chisue, I'd say 4K is probably not a bad bid. It is more expensive to retrofit than to install originally and it isn't quite as simple as just running some pipe under your existing floor. I don't see that the value of a 5K home in your neighborhood has much of impact on the conversation. From experience, the cost difference in many home retrofits and repairs in a high value RE value area, in the range you mention, and another in a low cost area, is not that much except when transportation costs of materials is at issue. In fact some services and inputs are more expensive in our lower home value area than in our higher value area, simply because more local trades that do higher end type installs are available and competing for work. From our experience we have to often hire someone from the nearby city --45 miles away -- to do the work and that does come at an up charge, understandably. There is also the fact that smaller jobs also cost proportionately more than larger jobs anywhere. It might help if you don't put down the trades as simpletons. If don't like the bid or can't afford that price, why don't you just go hire someone off the streets to install the tubing, direct the job yourself and just ask a master plumber to make a call to hook it up. LOL. Be sure to pull the correct building permit if ine is required -- it often is for additions to mechanical and plumbing systems.

Agreed Bry, that's a great point. In renovation or replacement comparison situations when a household is consistently using the baseline allowance, using the next tier rate up would be more accurate. It's also tough figuring out how much of the minimum monthly gas fee to include. I would guess the water heater may account for ~50% of usage so more accurate water heater gas costs would be somewhere near $302. Much tougher figuring the added comfort and space conditioning benefits of a HPWH and if the gas combustion appliance is naturally vented, there is probably added moisture and potentially health costs involved. For new construction, not knowing specific situations I think average kwh rates are where to start, and it's only the most energy intensive homes that would recover new infrastructure costs. Those outliers might be wise to improve the design. An energy rater would be helpful for plan specific comparisons. Mr. Fudd's Tier 2 kicks in at 202 kwh, lower than baseline allowances I saw digging around on the PG&E site. It must be an energy intensive area because most Tier 2 levels I saw were higher. This suggests the averages I linked to are close. Most tier talk for PG&E (serving a third of CA households according to this page) is about to be irrelevant as they are transitioning to Time Of Use rates for everyone. This makes sense for the increasingly renewable electric grid. For example, it will encourage electric vehicle owners to charge during off-peak hours and will keep electric water heating costs competitive with gas, even for replacement situations and even in places of high electric/ low gas rates. This requires the effort of putting a timing control device on a tank water heater, something those with basic electrical skills could DIY. Tying this back to topic, new construction skipping air-conditioning could use electric resistance (or heat pump) radiant floor heating during off-peak hours. The floor mass releases heat during on-peak hours of the day and an efficient envelope would keep it in. No combustion inside home necessary and cost effective if done right. A guy is doing it off-grid in Saskatchewan so it might be easy in CA. Here's a link to the controller he built for the PV to electric resistance radiant floor (or battery) interface.

Glad we now agree that 85 is an established threshold that radiant floor designers use as a recommended maximum for floor surface temperature. Foot contact with the floor makes the second way high temperatures lead to discomfort. 85 is evidently too hot for those expecting warm feet and will definitely lead to uncomfortably hot room temperatures, in efficient homes. There still seems to be confusion regarding water temperature and floor surface temperature. The temperature of the floor surface will be lower than the water temperature in the tubing. The water temperature entering the tubing loop from heating appliance, will be warmer than the temperature exiting loop, on its way back to the appliance to be reheated. The only mention I made of water temperature was that 125 seemed too high for an efficient home. Perhaps not for a long tubing run with short spacing but I still think it seems high and engineers generally don't like long tubing runs. I've personally installed tubing on a spec of mine and for other builder friends. We installed short runs with wide spacing for better zoning and they were for efficient envelopes. Few ended up being hooked up to an actual appliance. Why spend that money when the required AC can handle the heating too. The "at" which I corrected to "near" room temperature comments were in regards to floor surface temperature, which is a widely accepted fact for those involved in efficient construction. From All About Radiant Floors: "Why isn’t my floor warm? Homeowners who look forward to walking barefoot over warm floors are often disappointed by homes with in-floor hydronic heating. That’s because these floors are rarely as warm as most homeowners expect." From that article's case study (keep in mind difference of water temperature and floor surface): “On the design heating day [the coldest day of the year], the water flowing through the tubes in the floor will only be at 85 degrees,” said Robb Aldrich, an engineer at Steven Winter Associates" From energy expert Alex Wilson's article describing a level of home performance between passive house and international code minimum: "in a highly insulated house (and I’m talking about a really tight house with at least R-40 walls, an R-50 ceiling, and triple-glazed low-e windows), such a tiny amount of supplemental heat is needed that a radiant floor needs to be kept no more than a few degrees above the air temperature—or else overheating will occur. If a concrete-slab or tile floor surface is maintained at 72 or 75 degrees, it will likely feel cool underfoot—since it’s at a lower temperature than your feet. So you may not get that delightful benefit of a warm floor surface.