Gambit Weekly: What made you decide to move back to the city and write a book about retrofitting an old house to make it carbon free?
Stephen Hren: Most of [our decision] centered around the idea of being too dependent on automobiles and having to drive everywhere. We had not located ourselves where we needed to be hanging out, where we were working, jobs and everything. The book idea came along with moving back into the city. I had been doing restoration carpentry, fixing up old houses, so we had the idea of getting an older house, a fixer-upper and we thought it's probably possible to go ahead and convert a house and not use any fossil fuels at all.
Rebekah Hren: Also, a lot of people think that to have a green building you need to start from scratch and build a house from the ground up, so it was also a reaction to that. ... Lots of people think old houses are completely unsuitable to ever be energy efficient.
GW: How did you choose the type of house you'd like to retrofit?
Rebekah: We were trying to find a house that was really normal, that didn't have anything unusual about it just to show that you could take a normal house and make it energy efficient. We actually were looking for the most conventional house we could find, so what we wanted to buy was a 1950s brick ranch house because we thought that was probably the most ubiquitous house in America. But we couldn't find one that we liked.
GW: What projects should readers start with first?
Rebekah: Stephen and I both think that [renewable electricity] should be one of the last things you should do in the house. We think you should do all the other low-hanging fruit first and reduce your energy use as much as possible, and then you can install a much smaller photovoltaic (PV) system or renewable electricity system. There's so much terminology when you're talking about electricity that it's good to read that [chapter first] and get a grip on terms like volts and amps and watts before you start talking about other household uses.
GW: Are there certain projects you've found are more popular among readers?
Rebekah: People are picking and choosing among the projects but there are definitely some favorites: the clotheslines, potato barrels, turning down your water heater thermostat. Stuff like that people really pick up on because it's easy and you know people sort of feel bad that they haven't been doing it. It's definitely the things that don't affect your quality of life and are inexpensive that people pick up on first. And they're sort of fun, like growing potatoes.
Stephen: We really harp on the clothesline because drying your clothes in an electric dryer uses so much energy. People get into it; once they start doing it they actually like it. They find that it's rewarding, they like the way the clothes smell and it's such a simple thing to do to reduce your energy an easy way to be proactive.
Rebekah: And it's a lot of energy... if you use your dryer two to four times a week... you would have had to install a $10,000 solar electric system to just pay for (and generate enough of) the electricity you're using in your clothes dryer, so it makes a pretty huge difference.
GW: How do historic architectural and preservation organizations feel about the larger exterior renovation projects?
Rebekah: Stephen is a restoration carpenter and we're really connected with the historic preservation community in North Carolina, so it's been interesting. All the historic preservation people have been excited about it, because when you hear about green buildings a lot of times its not about historic buildings. We really wanted to emphasize that there's an embodied energy in old buildings and when you're rehabilitating those buildings you're saving a lot of materials from being created and you're working with the existing infrastructure.
Stephen: In our house, the solar water heater is very visible, but a lot of the times now, solar panels or hot-water panels are put flush with the roof so they're not sticking out in crazy directions. They're a lot less visible than they were, say, back in the 1970s or '80s.
Rebekah: Obviously it's a factor if you're talking about historic districts where there are rules and regulations. I've heard people say now that if you're putting solar panels on your roof you're (only) affecting the temporary look of your house but you're not affecting the long-term structure in any way. They could easily be removed [and] you can easily replace them if some technology comes along that is less visible. That's something important to think about for people who are contemplating solar panels or historic districts contemplating their laws governing things like solar panels.
GW: What should New Orleanians and others in our region consider when weighing carbon-free energy options?
Stephen: One thing that's important to realize is that solar hot water is a lot more efficient use of your money and investment than photovoltaics (for electricity). Nobody, especially in New Orleans, should be buying PV until they have a solar water heater just because when you're turning that sunlight into heat, it's much more efficient than turning that sunlight into electricity. I'm sure a lot of folks in New Orleans are heating their water with electric water heaters. PV is really one of the last things you want to invest your money in.
Rebekah: Especially since it rarely gets below freezing, there are some really inexpensive, high-efficiency water heaters on the market that would work amazingly well there. I think you could get close to 100 percent of your hot water from a solar water heater in New Orleans. You could completely eliminate your fossil fuel use for water heating pretty inexpensively.
In New Orleans obviously your air conditioning loads are a lot higher than your heating loads and there's various things you can do (to keep a house cool) you can get insulated curtains to close during the daytime, you can build trellises on the south and west walls. Probably you could have fruit trees or fruit vines that would grow there all year long along the south wall.
GW: What makes New Orleans a unique case for energy conservation and carbon-free living?
Rebekah: New Orleans is a special case because, probably of anywhere in the country, it could be served the best from some energy independence. There's so much sun there and the weather's so temperate that there's so many things that can be done so easily to gain some energy independence. It rains so much that it's just a really well-situated space for people to take back some of that dependence on the grid electric grid or water grid or sewage grid.
Stephen: We both have been to New Orleans very regularly. We both have a great love for New Orleans, and we love historic architecture. It has some of the best potential in the whole United States to be a green city.
Rebekah: And it's so much on everybody's mind there. People get frustrated because they think they have to spend a ton of money or hire somebody, but there are a lot of things people can do on their own there to put them in a much better position for the future. Any small steps help. There are a lot of things you can do yourself that are easy and inexpensive, that really will help you save money and lower your energy use, are good for the environment and really will make you feel better on a lot of levels.