Across the country builders are beginning to establish a "new normal" in homebuilding that includes more energy efficient construction techniques, better indoor air quality and improved use of environmental assets - all wrapped up into highly livable spaces. 

Winner of the 2010 Valley Forward Environmental Excellence Award - The Village at Paradise Reserve is an excellent example of progression in the industry. Natural habitat preservation, storm water management systems, solar systems, electric car plug-ins in every garage, LED lighting, plus heating/cooling systems up to 40% more efficient- it is a community of homes designed from the ground up to maximize environmental responsibility and efficiency.

Rendering of Village Vista Model 

So what was done on this project to garner that kind of efficiency?

An immaculate seal
When it comes to overall energy efficiency in the home, it is critical to start with a properly sealed thermal envelope. When an AC unit kicks on, air can be sucked through the weakest points in the seal and the efficiency can be severely compromised. Some of the most commonly overlooked areas for sealing include wall penetrations like wall switches, electrical outlets, plumbing, exhaust fans, vent pipes, ducts/vents, fireplace flues and dampers, satellite/cable holes, and where wood walls sit on concrete.

A poorly sealed home envelope with the best HVAC equipment will not perform as well as a well-sealed envelope with average equipment. To be a "super efficient" home, you need both.

The insulation factor
Using the right insulation is another critical component in a whole-house system. Batt and blown insulation are subject to installation deficiencies, so spray foam is preferred for a true whole-home system. Spray foam is hard to install improperly and it doesn't move, compress or create voids over time. Because it adheres directly to the surface of the wall, it is seated directly against a solid surface with zero airflow - both critical to obtaining full performance from insulation.

There is a general misconception in the marketplace that high R-value insulation is critical for energy efficiency when, in actuality, air tightness of the building envelope has a far greater return. A home with R50 insulation that is not air sealed is far less efficient than a properly sealed home with less insulation.

For The Village at Paradise Reserve, combating the intense heat Arizona experiences in the summer months was a key consideration, but the same extreme climate best practices apply to cold weather. Foam insulation is carefully sprayed on the underside of the roof deck, rather than batts or cellulose on the attic floor as is typically done. Because the envelope prevents heat from entering the home, attic vents are not necessary and all ducts are inside the insulation. Since the ducts are not in a super heated space, there is virtually no energy loss as the air is transported from the HVAC unit to the vent. Insulation is also sprayed on the garage walls and ceilings.

As a result, heating and cooling is captured inside the home with an extremely efficient thermal envelope. Indoor air quality is kept optimal through an air-to-air exchange unit and whole-house filtration system, resulting in a fully filtered, minimal dust environment.

Interestingly enough, it has become a top selling point of the home when the homeowner hears they can leave their desert home for months on end, come back and run their finger along furniture without experiencing the typical dust build-up. Because the building envelope is a completely sealed environment, dust and grime simply don't enter the home.

The air exchange also pulls out heat before air goes into the HVAC unit, leading to more efficient cooling and reduced energy costs.

Higher SEER units right-sized for the space
One of the best examples of smart green building in this community is the use of 20 SEER cooling/heating units on the home. Instead of the 13 SEER units that most homebuilders typically use, 20 SEER units with dual compressors were installed. The short-term cost of the more expensive units was balanced by needing fewer total tons for each home, plus it delivered the long-term utility bill savings and reduced energy consumption we were seeking.

We chose to use the Trane 20i Series, along with the Trane Clean Effects filtration system and Trane Fresh Effects air exchange. The units are the highest SEER available today, along with revolutionary double compressors and variable speed fans to handle both mild and extreme weather.

Individually zoned rooms for perfect control
We also treated each major room in the house as its own zone within the HVAC system. Each bedroom and primary living area has its own programmable thermostat, meaning the homeowner can heat or cool only those areas being used.

When combined with the highly efficient HVAC units and the thermally sealed building envelope, the zoning delivers a savings of up to 40 percent over comparable homes. This saves the homeowners money, while giving them a green home to be proud of, and is something very few builders are able to do. 

Last but not least
To complete the circle in a whole-house system of energy efficiency, it is important to include the more expected green build features, such as Energy Star® lighting and appliances, low VOC paints and stains, LED light bulbs, solar (where appropriate), low flow toilets and water fixtures, and other sustainable construction products.

As builders continue to educate themselves and improve their best practices, we can expect to see more projects like The Village at Paradise Reserve. It certainly will more firmly establish this "new normal" across ALL residential builds in the industry - not just the occasional project.