When it comes to green building, how much is too much?

Asked by Claudia
Kyle, TX

I will build a house soon in Wimberley, TX. I am starting the design. I want to be as green as possible. Do you recommend solar panels, geothermal, energy efficiency, rainwater collection, graywater... When is too much? I want to have things that make sense. Is there a perfect combination?


Randy Potter

Answered by Randy Potter

Alameda, CA

June 10, 2010

Too much green is really an existential question; can you be too green?

When we address this question it usually comes down to some form of financial analysis; i.e., is there some type of a payoff to what I am proposing to do? This payoff can come in the form of operation cost, construction cost, marketable value of the property, or simply comfort for the occupants.

Everything starts with an efficient building envelope, so begin your process here. First, have your home designed by a professional who practices passive solar design. Green systems and materials work only as well as the design of the house allows them to, so to truly get your money out of these upgrades you have to start with an intelligent design.

Next, spend more on critical building envelope materials and practices like blown-in expanding foam insulation, quality windows and doors, a durable cool roof technology and someone who knows how to put it all together.

Once you have your efficient envelope, look at mechanical ventilation (HRV or ERV technology) which will keep the air fresh in your new tight home and will also assist in operating it without much mechanics for heating and cooling.

Solar water should be next, cheaper and more efficient than PV solar. For water saving I would look at low-flow fixtures and aerators to help reduce water use. Greywater and rain catchment can help greatly, but rarely are able to pencil out as a financial decision.

Build tight and intelligently, then add some renewable energy systems if your budget allows. With this thinking, you can't go wrong.

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