How Much Energy Do Building Energy Codes Really Save? Evidence from California

On the Freaknomics Radio podcast last week ( they interview Arik Levinson about his recent article "How Much Energy Do Building Energy Codes Really Save? Evidence from California".

Here is Levinson's abstract about the article (see attached articles). 

"Construction codes that regulate the energy efficiency of new buildings have been a centerpiece of US environmental policy for 40 years. California enacted the nation’s first energy building codes in 1978, and they were projected to reduce residential energy use—and associated pollution—by 80 percent. How effective have the building codes been? I take three approaches to answering that question. First, I compare current electricity use by California homes of different vintages constructed under different standards, controlling for home size, local weather, and tenant characteristics. Second, I examine how electricity in California homes varies with outdoor temperatures for buildings of different vintages. And third, I compare electricity use for buildings of different vintages in California, which has stringent building energy codes, to electricity use for buildings of different vintages in other states. All three approaches yield the same answer: there is no evidence that homes constructed since California instituted its building energy codes use less electricity today than homes built before the codes came into effect."

What do you all think?

Tags: Energy, codes, energy, savings

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Someone might want to run as approach where they looked at what homes today would use today if codes were not enforced. How many homes in the 70's had an AC unit installed in the area and how many have air conditioning today.

We did not get AC in my house until the late 80's and I grew up in southern Florida.

How many households used an electric dishwasher? What was the average cf of a refrigerator in 1978. Probably not over 20. 

Homes built in the 70's have have 100 amp breakers. Homes today have at least one 200 amp breaker at a minimum. 

Occupant behavior has a bigger impact on electric use more than any other factor. My old man would have my ass if I left a light on in a room that I was not in when I was growing up. I go to homes on the regular where every light is on in the house and there are three TVs on in three different empty rooms. Across the past several decades how many homeowners left their television on all day long while they were at work, left a security light on all night long in their front yard, kept an 80 gallon electric hot water tank on hand so that everyone could have a hot shower every morning that could last as long as they wanted?

Totally agree Jesse. Very few houses had AC units before the 70's and now every house has one. Same with appliances, I grew up with nine dishwashers in the house - the children. Now homes have microwaves, toaster ovens, entertainment centers, computers (often one for every family member). The other thing is house size, in 1970 the average house size was about 1500 sq.ft. and last year it was 2600 sq.ft., 1100 sq.ft. more. My three-bedroom house build in the 1950 is only 1100 sq.ft. so the increase in square footage is like building two homes today for every one built in the 60's.

So I guess the answer to this is that yes we are using more energy now than we did before energy codes. The real question or answer should be what is the avoided cost or consumption if we don't upgrade the efficiency on our stuff?

Hand dish washing can actually be more energy intensive than the modern most efficient dishwashers.  There are conditions of course... but often had dish washing involves using far more than the 2 gallons total water that might be used in one drawer of a two drawer high efficiency dishwasher.

Microwave ovens use about 1100W, but for far shorter periods of time than the equivalent electric element oven.

The BIG Color TV sets and projection sets of the 70's could easily use 1000W or perhaps 1500W,  the new LED with BIG screens often come in  under 80W.

Refrigerator during the 70's were well on their way to using 1500kWh/yr,  now even a LARGE refrigerator with ice making, is around 550kWh/yr.

Clothes washers also saw big improvements!

You can track every one of the changes above back to  push for energy efficiency codes on the appliances.  EVERY ONE OF THEM.

So look at two appliances that made it nearly 50 years without EnergyStar labeling and minimal code changes to improve the energy efficiency.  

1. The plugin coffee pot...  brewing into vacuum thermal pots are possible.. but few are sold.

2. The clothes dryers.  Very minor changes had been made for years,  with the exception of the auto sense of dryness... and that became partly a safety issue.   The new heat pump dryers will offer some improvement for electric dryers.  But if you look at the available research, the patents,  the thermal process for drying,  it would have been possible to squeeze perhaps 30% more efficiency out of the electric drying process and perhaps 40%  more out of the natural gas dryers over the last 50 years.   But alas,  no incentive to do so... instead we saw color changes in the shape of the dryers, we saw, the look and feel of the dryers change,  but not the energy use.

Dryers are a good example of how the markets failed to improve the product - instead the manufacturers made minimal appearance changes and essentially kept the same old working engine for many years.

Now you can go back and look at the building codes and regulations.  Levinson made multiple mistakes - and one of the most glaring was not to compare California buildings in similar climate zones that were built before the codes with the code complaint buildings that followed over the years.  AND second if he thought the codes were not working - he needed to ask why - and that can be seen if you look at some of the buildings in the 80's and their condition today... lack of maintenance  on the items that would have made them more efficient.  Often simple things like putting the cover back on the doors of the air handler after changing the filter!!!!

Just to add that using graywater recycling and the septic tank effluent for outdoor landscaping as Earthships do drops water usage from 96-ga/day/person to 19-gal/day/person, so, for those doing hand washing this isn't an issue.

The power to run the dishwasher is an issue for battery capacity, using that for the pumps to move the recycled water around is more conservative.

There are also reports looking at the impact of grey water recycling and using it for the outdoor landscaping which show it may not always be the most efficient.   In Las Vegas  for example, the water that is returned to the sewers is recycled.... instead of planting lots of non-native landscaping and trying use the grey water... the water folks are discouraging that.

In Phoenix, the waste water is treated - then sent via pipeline to the Palo Verde Nuclear Power Plant where it is used for cooling water.

Yeah, and the nuke sends that electricity to California to make more money.

Obviously Phoenix doesn't need a nuke with that much solar available.

I guess that's too obviously a waste of greywater to me when if you grow algae at the Phoenix wastewater treatment plant from it it's worth 20,750-tons of nutrients to algae and produces about 3-million gal/day of biodiesel.

Hardly a better use than that for wastewater wouldn't you say? Or are nukes in the desert what to expect as "efficient"?

If you do not have an already built infrastructure to handle the sewage, then certainly greywater use as you suggest may be efficient.  If you are part of a community that has a sewage system, then greywater diversion for irrigating non-native plants can be far less efficient than returning the water to the sewer for recycling.

It isn't the nukes or energy, its the loss of potential potable water that the water and sewer districts are worried about.  All that sewage - is recycled to potable water... its not when is used to irrigate non-native plants in a dry climate.

The other major flaw in the analysis is that all energy is not electricity.  In California, meeting a specific heating or hot water load with electricity from the grid is more expensive and more environmentally costly than meeting the same load with natural gas.  Therefore, economics have pushed construction toward NG heating and water heating, while those technologies have gotten more and more efficient.  If he were to compare ENERGY usage across states, instead of ELECTRICITY usage, it is a virtual certainty that he would find California's usage to have been relatively flat since 1978, while the rest of the country's usage has continued to increase at roughly the same it was increasing before 1978.  We call that the Rosenfeld curve, since  (a) Art is largely responsible for encouraging the California Legislature to create the CEC (who promulgates the building energy code), and Art has repeatedly shown those two curves in support of California's EE efforts.

That said, there is a real issue behind what Levinson is saying; an issue that our industry needs to take seriously.  Just like most of the efficiency increases in automobile engines has gone into bigger.faster cars and trucks, our ability to design and build energy efficiency homes has led consumers to adopt more ways to use energy. It is fair to say that in 1978, no one in California had a computer in his/her home.  Now there are multiple computers per home. Since 1978, home office equipment and entertainment devices have become the largest sources of energy usage in homes. It's a little like whack-a-mole, but we need to more directly tackle the "new" energy uses.  ...and then the ones that will be "new" after that.

With Earthships as the model, what's missing in nearly all of those homes are fundamentals of thermal conservation.

There is no thermal collection on those homes, there is no thermal-mass to store that energy for the daily cycle plus some, there are very few solar hot-water units.

There are many ways to add these to existing homes, if you add in rain catchment & cisterns Earthships use 19gal/day/person while an average home uses 96gal/day/person. They rarely need backup heating and during the summer stay cool using the north side berm's soils to draw air from, thus no AC at all, the circulation doesn't need a blower, it's a thermal expansion from the warmth in the greenhouse.

These are lessons few architects & builders know, my work is integrating the principles into wood frame homes and have several valid approaches all using standard materials & methods in specific designs for that.

With a chance to build a demo tiny home using all facets of this, I hope to put metrics on it such that others will have confidence they work and pass code.

One of the obvious mistakes in the Elsevier article is: 

"And fourth, the five other states with the lowest per-capita growth in residential electricity use, also depicted in Fig. 2, are California’s western neighbors: Nevada, Oregon, Washington, Idaho, and Hawaii.3 All of this suggests the high-profile Fig. 1 may be the result of geographic and demographic trends unrelated to regulations."

A statement early in the paper showing "Figure 2" and a premise for why California code changes didn't make much difference.

If you look at his chart,  you'd notice that Washington State Energy use started to  go flat about the same time.  It did and for reasons similar to California; Washington state also adopted some aggressive energy efficiency programs, which included the start of blower door testing,  switching to CFL bulbs,  promoting conservation and energy efficiency before building out new plants.  The justification in the case of Washington State,  was a  severe drought that left river flows on the Columbia lower than normal, battles over the dams - and - migrating fish, a push by the Washington Public Power Supply System and BPA to start the build out of 20+ nuclear power plants.   The later caught the attention of a lot of people and the result was codifying energy efficiency first as part of the utility plans for transmission, generation, and future planning activities.

Instead of arguing that Calfornia didn't have as much of an impact - and using the nearby peer states,  the author needed to look at what was happening in those nearby states - and understand that similar societal (energy use) changes were happening in his reference states -- all backed with code/regulation changes unique to those states - AND triggered by many of the same reasons that California made their code changes.

Levinson, while he may have his PhD,  did some bad science and analysis.  If you can kick the supporting legs of his premise as easily as seen with the Washington peer state examples above... how many of the outer basic support legs would go and cause his hypothesis to fail....

The bigger problem is taxpayers/government provides heavy subsidies to keep utility costs down for the end user. You are effectively paying much of your energy bill through taxes instead of utility costs. Get rid of energy subsidies and let energy costs rise to their natural levels a they have in other countries. Only then will the average consumer become concerned about conservation.

+1 to this. We all as consumers need to do more.


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