Catching Rain: A Home Builder’s Perspective
Photo above: One of Darrel McMaster’s “Sustainable Homes,” built in the Hill Country of Texas near Boerne. The house produces all of its own energy and water, known as “net zero.” The rainwater cistern can be seen to the right of the house.
_________________
After posting my recent blog about rainwater harvesting, I received a very interesting note from a home builder in Boerne, Texas. Darrel McMaster has been building homes for more than 40 years, but in 2006 he set out to build “Sustainable Homes” that would run 100% from what nature provides, meaning net zero energy and water use!
His story, and his homes, are both mind-boggling and inspiring.
As you’ll read in Darrel’s interview responses below, it’s too early to call the building of net zero homes a full-on movement. There are a lot of hurdles to overcome in the process of home building to enable full-scale adoption of net zero concepts and technologies. It’s going to take architects and engineers with the knowledge to incorporate appropriate energy and water systems into home designs. It’s going to require county and state planners and building departments willing to embrace — if not promote — the concept. And it’s going to need communications, the telling of the message that net zero is possible and feasible, so that homeowners will start to ask for it.
I share Darrel’s story with you to help us all envision what our future homes could look like, and how they could function. We can substantially lighten our energy and water footprints if we begin to apply some of these approaches.
Darrel McMaster, president of Sustainable Homes in Texas
Q: You’ve been a home builder for 44 years, but in 2006 you decided to start building some very different homes. What motivated you, and what do you hope to accomplish?
I had lived in the mountains years ago and was experienced in rainwater harvesting and solar. But the main thing was when I was growing up I was involved in scouting and we were always taught to leave our campsite in a better condition then you found it. To be honest, that’s something we haven’t done. I have 4 kids and 8 grandkids, and I want them to have the same freedoms and see the same beauty of this country that I saw. I don’t ever want one of them to say to me why didn’t you do something with the knowledge and experience that you had. It can’t always be about the money. So two things motivate me: to distinguish my business proposition, and to leave this place better than I found it.
Q: On your website you emphasize that you’re building homes that are highly efficient not only in their water use, but also in their energy use. How efficient are the homes you’re building?
Our homes are designed and built to take full advantage of what nature gives us for free. So all our water for the entire home comes from rainwater harvesting, all our wastewater is treated onsite and reused in sprinklers in the backyard. Our homes have geothermal energy for our HVAC, and with a desuperheater so we get 7-9 months of free hot water (our second biggest energy user in the home). We size our solar arrays to power our homes to net zero energy on December 31. We want our homeowners to avoid having to purchase any energy from the utility. Our solar arrays also generate enough power to power the owner’s electric vehicles. We view our homes as a generation station, not just a domicile.
Q: You say that you’re able to build homes that are “net zero” in terms of their need for public water supplies, meaning they don’t require any water other than what’s generated onsite. What’s the key to making this happen?
Rainwater harvesting, as you know, has been around since the old testament of the Bible. We know that a properly designed, professionally installed RWH system will work almost anywhere in the country. As an example we know that a home in our area with 3000 sq ft of collection (that can be a 2400 sq ft home, a garage, patios, porches, etc) can provide all the water that a family of four would need. We use 150 yr rainfall average in our designs and figure in the drought of record in that process. We had the drought of record here in 2009 and not one of our systems got below 50% of storage. We have been blessed by having great owners who give us their water records yearly — their month by month usage — so we know what products work the best on truly saving water. As a general rule we have at least two water meters on a home, inside, outside, if they have a pool we have a third. So we know if they are going to put in a pool how much storage we will need to add based on the pool size. Our first homes were built before low flow fixtures and toilets, and those homes average 40-42 gallons per day per person. As WaterSense products came along that number dropped; when front load washers came along, down it went.
Now THAT’S a rainwater cistern! The large cistern installations in McMaster’s homes ensure that his homeowners will have water even in drought periods.
Q: How many net-zero homes have you built?
We built a number of homes that we called “sustainable” from 2006 to 2009 — maybe 7. In 2009 we built our first home that we called a Point Source Home™. These were the first homes that included all of the components we use now, including powering the owner’s car. We’ve now built maybe 20-22 of those, they range in size from 1500 sq ft to over 12,000. When we first started building this way we were told by the so called experts that we could never build a home that could generate all of its utilities from the environment. Then this same group told us we could never do it at a price most homebuyers could afford. Our homes on average cost 8-10% more than the standard custom home, with a payback period on those extra costs in 48-54 months.
Q: Do you think there’s a lot of homebuyer interest for homes like this?
I’m sure some have at first, but you can buy potable water, 6000 gallons for $450 dollars, from our local suppliers if you need it. We know this because some banks have wanted a back up in case it didn’t rain. Our systems are designed to go 8-9 months with no water. So we might have a 30,000 gallon tank. As far as energy goes, all but a few of our homes are grid tied. They have batteries, and the systems are designed to run off-grid in case of no power. When we experienced Snowvid here last winter our owners were able to help others in the neighborhood who didn’t have power or water for days.
Q: I presume there are some ‘inconveniences’ or maintenance requirements for your homes that are different from typical homes. What does that look like?
Not really, less than 4-5 hours annually is all it takes and that is changing filters and the UV light in the RWH system.
Q: Is going to net zero on water cost effective? Does it raise the cost of your homes? How much does the rainwater harvesting installations in your homes affect the purchase price?
Not really, there are some Green Bling builders out there who are using the appearance of doing something but it’s just a marketing tool from what I have seen. I have met only a handful of builders across the country who do some but not all of what we do. This is a big step for most to believe that we can do this. Can’t tell you the number of buyers who have said to me, “If you can actually do this and it works why isn’t everyone doing it”? Great question!
Since the mid-70s, every new car in this country must have an MPG (miles per gallon) sticker on the window to tell the car buyer what it will cost for gas to run that car, so why don’t we have a similar metric for the energy use of homes?
Q: Are there policies or other impediments that need to be changed before we’ll see a more widespread movement toward building these types of homes?
Presently we are working on a business park that uses the same concept and also a subdivision of these types of homes. You can only imagine when I explained to the county commissioners that I didn’t want their water or sewer, that we were going to generate it all onsite, treat it all onsite and reuse that water in the landscape. All of this is legal in the state of Texas and meets the state rules and regulations. We have been told we think outside of the box, we just think it’s time for a new box. We think it’s time to rethink what our homes can and should be.
About Post Author
This is an inspiring article! Using many of the Drawdown solutions in concert. Along with the solar panels in the roof, other parts of the building depicted show “cool roofs”, reducing summer cooling demand. As noted the combination of net zero building WITH net zero water usage is very inspiring.