Minimizing the cost of utilities by area

[jacob]

@Fish - I know that map. If you combine the two, that means that there's NO place in the US one neither needs neither HVAC now nor in the future. Current optimization for now is NorCal, TN, GA, ... in the Future, it's PNW as those areas become rather harsh.

The "some-HVAC" areas are more interesting. Now, the Great Lakes region become a possibility.

[black_son_of_gray]

Is there a specific reason to exclude underground/partially underground homes from this discussion? Seems like that single aspect of a house's construction could make a much broader range of geography meet the criteria.

[jacob]

They're not excluded as much as they aren't included. Ditto super-insulated homes. Not found in existing housing stock.

[sky]

According to map b, my climate region (southwest mi) would see a 24% reduction in heating and cooling degree days.

[Riggerjack]

PSA since the PNW keeps coming up here:

In 2009, some geologists predicted a 10% to 14% probability that the Cascadia Subduction Zone will produce an event of magnitude 9.0 or higher in the next 50 years.[26] In 2010, studies suggested that the risk could be as high as 37% for earthquakes of magnitude 8.0 or higher.[27][28]

From Cascadia_subduction_zone

The last one wiped out the coast, and sent a tsunami to Japan, wiping out their coast. FEMAs "working assumption" is that "everything West of I-5 is going to be toast". So that should fix the HCOL at some point...

But yeah, mild climate, and cheap electricity, at least until the Green on Green battle over the evils of hydro power resolves.

[Jin+Guice]

Wouldn't it be possible to mitigate the now vs. in the future problem by renting or one well timed move? Have housing prices started to react to climate predictions/ changes yet? My naive impression is that they haven't.

[jacob]

Yes and no. At some point the doors will shut/prices will respond. This is a fire-exit in a theater kind of problem.

Three years ago there were almost nobody who talked about what impact sea rise would have on coastal properties. Now it's a common subject of in-depth journalist articles. There's some talk about whether/when insurance companies will refuse to insure coastal properties in low-lying areas. Most home-owners need to borrow to buy. No insurance, no mortgage. That's a huge drop in demand and therefore price from a single policy change. In short, if an agile response really requires one to be able to relocate on a time-scale of 12-24 months.

[Jin+Guice]

I actually meant this from the opposite angle for the purposes of this thread. Assuming that there is a current optimal or near optimal utility area that is not in a coastal region that will be subsumed by rising seas or threatened by increased occurrence of natural disaster (so conditions will just go from optimal to sub-optimal in terms of climate, not optimal to disaster), a well timed move could keep one at or near optimal HVAC conditions for the remainder of their lifetime. In this case the time-scale for a move would be closer to a decade?

I'm not pitching this as a great plan that we should all follow, I'm trying to think of how to optimize along the sole dimension of minimum HVAC bills. I think it's interesting to take the PNW out of play due to the risk of earthquake and current high home prices.

I was wondering if prices have started to rise in areas that are likely to see climate improvements in the next 20-30 years.

I'm surprised current conditions don't favor the west more drastically because I would think humidity is a huge factor. It looks like the future will favor the great lakes area and more northern regions that will become more coastal?

[Lucky C]

You really need to take passive solar heating potential into consideration, so not just HDD but the orientation of the house, the sunniness of the climate, and the amount of glass with southern (in northern hemisphere) exposure. The difference in heating & cooling requirements can be very significant between a house running (the long way) east-west with a lot of south-facing glass, vs. a house running north-south (most windows getting the hot summer sun in the morning and late afternoon, with hardly any getting sun in the winter). This is a bigger factor than say Chicago vs. Seattle, and is true of any old house, not just one designed for passive solar.

The good news is that most normal buyers will not be taking house-sun orientation into consideration so you do not need to pay a premium for these energy savings which could easily be 30%+!

Per this article, the best locations for passive solar, considering these factors and utility costs, are the Northeast (excluding cloudy areas like Buffalo) and Denver (sunnier but lower utility costs than in the Northeast).
https://www.greenbuildingadvisor.com/ar ... -heat-gain

They're not excluded as much as they aren't included. Ditto super-insulated homes. Not found in existing housing stock.

Don't underestimate the ability (and potential ROI) to retrofit an old house, if it's the right type. I've estimated high ROI (10-50%+) for our efficiency improvements in our 1950's ranch, and reduction of energy load by 50%+ (though this may optimistic as it is a simple heat loss calculation that does not account for air tightness or lack thereof).

All of these projects should be >10% ROI, though I guess if you don't plan on living there long you wouldn't be motivated to do these things and you might not get your money back when reselling.

1. Adding R-38 in the attic on top of existing layer, trivially easy.
2. Removal of long leaky duct run to addition which will now be conditioned independently as needed with an efficient mini-split.
3. Air sealing and insulating ductwork.
4. Insulating floor between living area and unheated basement (could instead insulate basement but that doesn't make sense for our situation)
5. Adding a layer of insulation on the interior side of some exterior walls (to be covered by drywall, built-in bookshelves, etc.)
6. Removal of a porch roof (turning it into a deck) which was shading south-facing patio sliding doors (should provide passive solar heat equivalent to almost 50 gallons of oil per year!)

So besides the whole southern exposure consideration, you'll want to look for a house with the space/access to potentially add another foot of insulation in the attic (stay away from flat roofs for this and other reasons), and preferably an unfinished basement (slabs are hard to improve and finished basements would be costlier while probably being under-insulated and a having a decent chance of moisture-related issues).

[Lucky C]

Also, my house is near Providence RI (ranking near the top of passive solar value), is oriented within 15 degrees of true south, with east and west windows shaded from the summer sun, and roof-mounted solar panels (close to ideal solar angle). My bills are:

Electricity rate: $0.21/kWh including all fees. Some of the highest rates in the country, but RI is also the lowest per capita electricity use in the country.
My electricity bill: $0 with solar panels (ROI of 12% and didn't have to do any of the work myself). Without solar we'd be looking at around $1200 in electricity per year

Heat: Started at $1600/year keeping the house at a nice 68F with terrible air leaks (some ducts had wide open gaps) and poor insulation. Oil heat. In theory it should be easy to get it down below $1000/year.

Air conditioning: Hardly use it, mainly just a couple weeks of the year, and really none has been absolutely needed since we moved here, since the sun doesn't come directly into any windows in the hottest months and the attic is now well insulated.

Water: well water (normal in our area). A few $ per year in electricity to run our pump. A few hundred every X years to replace the pump.

Sewer: septic tank (normal in our area). $200 every four or so years to pump it.

Hot water: lower than average with an insulated tank and keeping the temp at 110F, but again higher than average electricity rates.

Also, Rhode Island still has more than one internet provider (Cox and Verizon) so there can be some savings due to competition there

[Laura Ingalls]

Yeah, many US islands enjoy little temperature variation year-round. Saipan has the least-fluctuating temperatures in the world.

When DH and DS1 went to Hawaii their host had no heat or AC. It was 74 degrees for days on end. Not sure it meets your criteria as they had municipal water and sewer and were on grid for electricity all expensive.

[Lucky C]

Allow me to ramble a bit more on solar gain considerations... Check out this pub from 1983 (no reliance on newfangled technology): https://www.uky.edu/bae/sites/www.uky.e ... S-34_0.PDF
My house and lot is very similar to Fig 1 and it ticks off most of the boxes in the summary, albeit not as efficient as a house designed for passive solar. Again it's just a plain-looking 1950's house that was cheaper than a lot of other houses in the area. It's just a matter of looking for the right type of house and lot on streets running east-west to get this "free lunch" of lower energy bills.

Currently, passive solar with just our regular sized windows provide roughly 10% of our heating needs. After converting our big patio doors from shaded to passive solar, my spreadsheet says passive solar will cover over 20% of our heating needs, with the caveat that we would need to run some fans to distribute that heat where we want it.

Jacob, I assume you still keep your thermostat at something like 55F. At that temperature your HDDs would be almost exactly half of mine (in Providence according to www.degreedays.net). Therefore passive solar is potentially twice as important to you than me. Based on my estimates, passive solar heating could provide 20 - 40% of your heating needs! Again that is with an old house and just a few thousand dollars of insulation added to easily accessible areas. With such a high passive solar potential, you may even be able to get a good ROI modifying the south side of a house with more/different glass (high SHGC and shutter/insulate at night).