Steven Nadel是美国节能经济委员会执行主任。这篇文章最初出现在Aceee博客. GBA发布了新闻故事关于1月份的原始研究。

Aceee是一个强大的支持者分析能源效率计划，以便看到他们所取得的成就并学习课程，所以我们可以做得更好。因此，我们审查了兴趣建筑能量码确实节省多少能量？来自加利福尼亚的证据by Arik Levinson.

In this paper Levinson conducts several analyses and concludes that “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.”

在表面上，他对建筑码功效的结论与最近分析的效果非常不同，所以我们越来越深。

建立联合业务厅的能源代码主要通过用于空间加热和空调的能量，对水加热能量产生影响。此外，商业建筑码还以实质的方式解决灯光。因此，对代码的效果的任何分析需要看看这些最终用途的能量消耗。

加利福尼亚的能源使用

Levinson is examining California, so we should start by looking at how California heats and cools its buildings and water. The California Energy Commission had a consultant prepare a report looking at residential appliance saturations in 2009. They found that 93 percent of California homes are heated with gas and only 5 percent are heated with electricity. Likewise they found that 87 percent of homes have gas water heating and only 7 percent use electricity for water heating. Central air conditioners are used in 49 percent of homes, with an additional 15 percent using room air conditioners.

California added a limited lighting provision to its 2008 residential code, but the savings are too recent and too small to show up in a long-term analysis.

基于此信息，对加利福尼亚州住宅建筑规范的分析应专注于天然气使用，仅限于电力。不幸的是，这与Levinson所做的相反。他的大部分分析都是电力使用，并且他通常排除电动空间或水热的家庭。他这样做是因为电空间热量的饱和随着时间的推移而变化，因此根据Levinson，因此不适合他的时间序列分析。因此，他的分析寻找建筑规范对空调能源使用的影响。

California’s mild climate is a factor

然而，事实上，加州的气候有轻微的气候，并且根据能源信息管理局（EIA）的最新分析，只有4％的加州家庭能源使用是用于空调。使用EIA数据，我们可以继续计算空调代表家用电力的约10％（与能量）使用。如果我们制作球场估计，代码减少空调电力使用30％，Levinson正在寻找数据节省3％。

Furthermore, a majority of the savings in air conditioning energy use is probably due to air conditioner efficiency standards that also apply to replacement equipment in existing homes. Since Levinson is comparing new and existing homes, of the 3 percent savings mentioned above, perhaps 2 percent are also being achieved in his comparison group of existing homes.

因此，他正在寻找新房的储蓄效果1％。在统计分析中找到如此小的效果是非常困难的;随着效果小，在统计分析中显示出这样的储蓄比储蓄没有出现，就会更令人惊讶的是。

In addition, it should be noted that the rising saturation of electronic gadgets in U.S. homes may be affecting new home energy use, a factor Levinson does not examine but that perhaps explains some of the increasing energy use he found in new homes.

Study should focus on natural gas

A good analysis of the impact of California’s building codes should focus on natural gas use. Levinson does do one analysis of natural gas use, finding that homes built since California’s building energy code began use less natural gas than earlier homes.

However he then dismisses this finding since the trend started before the building codes took effect. He presents no evidence that prior trends would have continued, and therefore his claim that building codes had no effect is speculation.

Finally, if the objective is to examine all building codes and not just some codes, then it’s also important to look at commercial buildings. According to an analysis by Pacific Northwest National Laboratory, nationwide about 69 percent of building code savings in 2012 were in the commercial sector and only 31 percent in the residential sector.

超过80％的商业储蓄占电。

Bottom line: Levinson is on the wrong path if he’s trying to see the impacts of building codes. If he wants to see the forest — the impacts of codes or their absence — he needs to understand the trees. He needs to look where the impacts are supposed to be, and in California this means residential natural gas and commercial building electricity use.