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Texas Gets Two High-Performance Subdivisions

Developers announce plans for 'energy neutral' and 'solar standard' communities in Austin, where the city council wants more renewable energy

Posted on Oct 5 2015 by Scott Gibson

UPDATED Oct. 8, 2015

Work is underway in Austin, Texas, on two housing subdivisions that emphasize energy efficiency, including one in which all 7,500 homes will be constructed to zero-energy standards.

Taurus of Texas, a real estate investment firm, said in September that it was starting construction of the first 237 houses at Whisper Valley in East Austin, according to a report at MyStatesman.com. Company officials said it would be the first large single-family development in which all houses were designed to produce as much energy as they use on an annual basis.

Houses also will come with fiber optics systems from Google Fiber, which says Whisper Valley is the first time the extremely fast internet service is being installed in a new housing development.

Separately, Lennar announced it would build Austin's first "solar standard community" where each house would have its own rooftop photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. (PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow.) array. Homeowners could either lease the panels or buy them outright.

The first phase of Lennar's Colorado Crossing subdivision, underway near the Austin-Bergstrom International Airport, will include 120 homes, ranging in size from about 1,200 square feet to 2,800 square feet and costing between $195,000 and $277,000, MyStatesman said in another report.

Balancing performance and price

Construction details about houses at Whisper Valley weren't available, but MyStatesman said that the intent was to seek a market niche where houses with low energy demands also would be affordable. Taurus expects to price the houses between $150,000 and $275,000, which is higher than the median market value for the immediate area around the development but about in line with the median market value in the Austin metro area of $267,000.

Taurus partners include Bosch, which will provide energy-efficient kitchen appliances, ground-source heat pumps, and water heaters; Google Nest, which will supply its web-connected thermostats; and Google Fiber.

The web report said that Whisper Valley residents will pay a fixed utility fee averaging about $175 per month, which would cover the cost of the rooftop PV, an LED lighting package, the Bosch appliances, ground-source heat pumps, and maintenance costs.

In addition to the zero-energy houses, the development also will eventually include townhouses, apartments, and more than 2 million square feet of office and retail space. A second phase of the project, including 200 additional houses, would be started next year.

MyStatesman said that Taurus bought 2,062 acres for the project in 2006, but the development was sidetracked by the real estate and financial markets' meltdown. Later, the company partnered with the City of Austin, which issued bonds to finance highway, water, and sewer lines in the area in return for the company's help in achieving Austin's carbon-reduction goals.

Solar panels for everyone

At Colorado Crossing, home buyers will be able to choose between leasing or buying the solar panels on their homes, but they won't get the chance to say "no thanks." Every house in the subdivision gets them.

The panels will be installed and maintained by SunStreet Energy Group, a Lennar subsidiary, whose CEO said that the decision to include solar was not so much about "being green" as about making sound business decisions.

"This is about consumer relevance, this is something they want,” he told MyStatesman. “We have not built this business on being green — this is a real business built on economics and consumer needs.”

Homeowners who buy the systems will pay $15,000 upfront, although they will be eligible for the 30% federal investment tax credit through the end of 2016. Home buyers who choose the lease option will pay between $45 and $65 per month, the company said, depending on the size of the system. Homeowners who lease their systems will buy their power from Austin Energy at a discounted price.

It wasn't clear how big the arrays are, and GBAGreenBuildingAdvisor.com was unable to reach anyone in the company who could offer additional information on solar capacities or mechanical systems. However, David Kaiserman, SunStreet Energy's CEO, told the website UtilityDive.com that the panels were expected to meet about 60% of each home's electricity needs. The systems range from 3.18 kW to 5.3 kW in capacity and average 3.45 kW.

According to the Colorado Crossing website, the slab-on-grade houses are insulated to R-15 in the walls and between R-22 and R-38 in the ceilings and come with radiant barrier roof decking to reduce attic temperatures. "Technology" features include programmable wi-fi capable thermostats. Houses are heated with gas furnaces and cooled with Lennox 16 SEER(SEER) The efficiency of central air conditioners is rated by the Seasonal Energy Efficiency Ratio. The higher the SEER rating of a unit, the more energy efficient it is. The SEER rating is Btu of cooling output during a typical hot season divided by the total electric energy in watt-hours to run the unit. For residential air conditioners, the federal minimum is 13 SEER. For an Energy Star unit, 14 SEER. Manufacturers sell 18-20 SEER units, but they are expensive. air conditioning systems.

Lennar is using the IRCInternational Residential Code. The one- and two-family dwelling model building code copyrighted by the International Code Council. The IRC is meant to be a stand-alone code compatible with the three national building codes—the Building Officials and Code Administrators (BOCA) National code, the Southern Building Code Congress International (SBCCI) code and the International Conference of Building Officials (ICBO) code.'s performance-based method for code compliance. The houses, which are inspected by an independent third party, "consistently" receive HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. scores in the mid-60s, the company said.

The company said that 20 homes have been completed, with a total of 35 sold. A second and possibly third phase, with another 120 houses each, are in the works, but Lennar didn't have a firm timetable for a complete build-out.

The right opportunity for solar

David Grove, Lennar’s division president for the Austin and San Antonio markets, said by telephone the company had been looking into adding solar for a number of years but until now hadn’t found a way to make it available affordably in the Austin market. SunStreet’s lease option made the difference.

“I think it’s clear that homeowners want solar, they want technology,” he said. “If you asked anybody off the street, ‘Would you like solar on your home, and do you understand it makes sense?’ the answer is a resounding, ‘Yes!’ The challenge has been what a homeowner is willing to pay, and that’s always been the prohibiting factor. Now we’ve found a way to provide the solar without the homeowner paying out of pocket at a reasonable, very economical rate.”

Lennar is the country’s second largest builder, with $6.8 billion in housing sales and 21,000 closings in 2014, according to Professional Builder. The company has roughly 120 solar communities underway in several states, including California, Colorado and Maryland, adding up to “several thousand rooftops” in all.

Lennar expects to launch a second solar community in Austin early next year. “And strategically,” Grove said, “I think we will try to pursue it in every community we open moving forward, and then we execute it where we’re able to.”

“Folks historically have looked at solar as something that you’re only going to see on expensive, million-dollar homes because they have the ability to utilize it and it’s cost prohibitive to others,” he continued. “I think as we make this more commonplace and expand the footprint it will become more and more the norm.”

Grove expects most if not all buyers at Colorado Crossing will opt for a solar lease, not an outright purchase. Leasing is by far the most common way homeowners go solar, accounting for as many as 95% of PV installations at Lennar subdivisions, particularly in areas where buyers don’t have a lot of discretionary income, Grove said.

Lennar is technically creating power-purchase agreements with buyers rather than straight leases, The Wall Street Journal notes, because homeowners pay only for the power they use and not the system itself. But homeowners are paying less for electricity than they would from the local utility, so they are saving money regardless of what the arrangement is called.

Austin aims for 55% renewables

It will take developments like these if the Austin City Council is to reach its aggressive efficiency goals. Last December, the city approved a plan to get 55% of its power from clean energy by 2025, Climate Progress reported.

In addition to providing 600 metawatts of utility-scale solar, the proposal would have Austin Energy, the municipally owned utility, find 200 MW of local solar, at least half of which would have to be owned by customers.

Energy efficiency and improvements in demand response were to provide another 800 MW of power over the next 10 years.

“It’s clear that to achieve the ambitious goals Austin Energy has set for itself, we must significantly increase the number of rooftops generating power from the sun,” Austin Energy vice president of customer energy solutions Deborah Kimberly told MyStatesman. “Communities like this with solar integrated into the design from day one allow us to make faster progress toward those goals in ways that allow us to plan infrastructure and protect the overall stability of the electric grid.”


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  1. Lennar

1.
Oct 6, 2015 2:57 PM ET

In Texas, its easy.
by ven sonata

It doesn't take much to get to net zero in Austin! R-15 walls, how nice it would be. Uninsulated slab, again probably appropriate since they are more cooling oriented than heating. What is interesting is ground source heat pumps. Obviously overkill for heating but they must be economical for cooling. It doesn't say whether it is air distributed cooling or in-floor, I suspect air since the slab in uninsulated. The panel array is likely 5 kw at $15,000 which is supposed to produce 60% of their yearly requirements. They will have to source the rest from grid solar. This is a slightly different definition of net zero since the individual house does not attain it, but the community as a whole does. By the way, 5 kw produces at least 8000 kwh per year in Austin. If that is 60% of total then the total electric demand is 13,500kwh per year. That is living rather large, I must say, though of course it is Texas after all.


2.
Oct 6, 2015 3:10 PM ET

I'm surprised that it's do-able with R15s, even in Austin!
by Dana Dorsett

The simplicity of the shape helps a lot (the "shoe-box with gable" look), but even then it's tough to hit Net Zero with an R10-ish whole wall, R11-ish if one takes some pages from the Advance Framing book. Which means they have to be counting on true state of the art performance out of the GSHP systems.

Austin's climate averages about 3000 CCD and 1600 HDD, so the GSHP will have signficant load to deal with if the building isn't sufficiently low-gain. The picture doesn't look like they skimped much on the west facing glass, and there's not much overhang to shade the south facing glass. Let's hope they simulated it adequately.


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