According to the Department of Energy (DOE), 39% of US energy consumption can be attributed to residential and commercial buildings. With more than a third of our energy resources gobbled up by structures large and small, it makes sense to employ stricter building guidelines so that our future homes and offices can be more energy—and economically—efficient. The question is—can we start small or should we aim big?

In Europe, buildings—many of them old and drafty—account for nearly 40% of the European Union’s (EU) energy use. As reported in the New York Times (“Packed With Drafty Old Buildings, E.U. Pushes for Energy-Neutral Designs”, the EU has decided to take action to not only reduce energy use, but carbon emissions. And so, by 2020 the EU will require all new buildings to produce as much energy as they consume.

How does the EU expect to enforce this mandate—especially at a time when economically challenged countries are loath to earmark currently strained resources for future savings? The EU plans to allocate some money to help member-states meet the mandate’s estimated €8 billion price tag. And the future payoff certainly dwarfs current expenditures: an estimated €25 billion per year in energy savings, as well as the creation of anywhere between 280,000 and 450,000 jobs (primarily in construction and manufacturing). The promise of billions saved and jobs created is certainly alluring, but many countries are weary of the EU’s latest round of promises, unsure of exactly how and when the promised incentives will materialize.

For some countries in Europe, the path to the 2020 requirement started years, if not decades, ago. In Denmark, for example, energy efficiency requirements for buildings have been in place since 1977. And while the 2020 EU deadline might seem onerous, many European countries are already well on their way to meeting, if not superseding, the EU’s mandate. In Britain, for example, all new buildings must use 85% less energy and produce 95% less CO₂ by 2013.  By 2016, all new buildings in the UK must produce more energy than they consume—a deadline that’s four years ahead of the EU’s mandated deadline. In Ireland, “energy-plus” houses will be required by 2013, and France and Germany anticipate hitting that goal by 2020.

Of course there are regions of Europe that will struggle with the EU’s mandate. Both Poland and the Czech Republic have some of Europe’s worse building efficiency standards. And in Denmark, a 50% efficiency mandate by 2015 means that “a new house built in Denmark that year will consume 25% more energy than a similar one in Ireland, Germany, or France.”

The challenges and obstacles faced by countries attempting to improve the energy efficiency of their structures are familiar—budget deficits and unskilled workers. While Europe has traditionally been a world leader when it comes to low-carbon technologies and “zero-carbon” construction, the EU must find a way to deal with the economic disparities between the region’s prosperous countries and their struggling neighbors.

Some of the solutions proposed include training programs to teach energy-efficient techniques and technologies to the construction industry as well as low-cost loans and government subsidies. But there’s little money to spare, and some experts are pointing out that it’s a mistake to focus on new construction when existing structures are still responsible for the majority of lost energy and CO₂ emissions in Europe and around the world.

Arthouros Zervos, president of the European Renewable Energy Council, said in a statement (quoted in the New York Times), “Existing buildings represent about 99% of the buildings stock and are the first cause of CO₂ emissions before new buildings. A mandatory target for upgrading the existing building stock would be a useful tool.”

So what do you think? Are there lessons to be learned by gazing at the glaring divide between the EU’s goals and Europe’s ability? Are we also in danger of focusing on future success while failing to employ simple solutions that could give us modest—but immediate—payback? Should we be focusing on the “new”—new energy sources, new construction, new technologies—to the detriment of existing solutions like building retrofits and powering down appliances and gadgets when they’re not in use? Can it be as simple as turning off the light in an empty room, or are we at the point where simple solutions can no longer help, and bolder action must be taken?