Energy Star Home – The Hybrid Construction Way
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Over 1 million Energy Star Homes have been built to date in the US. Compare this to just over 6,500 LEED Certified homes and probably less than 20 Passive House Certified homes in the US. While Energy Star is much less stringent than the latter certifications, it is easy to see which standard the bigger [...]
Over 1 million Energy Star Homes have been built to date in the US. Compare this to just over 6,500 LEED Certified homes and probably less than 20 Passive House Certified homes in the US. While Energy Star is much less stringent than the latter certifications, it is easy to see which standard the bigger production builders are turning to first in an effort to respond to the market’s demand for more environmentally friendly homes.
An Energy Star Home is basically trying to achieve 15% higher energy efficiency overall when compared to the same house built to code minimum standards. Our big two questions when forming Hybrid Construction were, “Is 15% efficiency improvement over code enough?” and “How many of the builders out there are just barely squeaking by with very minimal changes to the design of their old homes?”
There are some builders out there knocking the socks off of Energy Star standards, especially those participating in programs like the US Dept of Energy’s Building America and Builder’s Challenge programs (see chart above). This is swell, but for every builder that is far exceeding the minimum standards, there are probably 5-10 others that are doing the bare minimum to pass. We won’t name names, but we’ve heard a few stories of decent sized local builders completely missing the mark on large developments where Energy Star Certification had been advertised to consumers from the beginning. Insert embarrassing failure sounds here.
On to the point of this post. When we decided to launch our new construction company, Hybrid Construction, we realized that not everyone would have the need or desire to build to LEED or Passive House levels of construction. Therefore, we turned to Energy Star as a suitable target for our base level option in any Hybrid home that we are hired to build. When we sat down to think about it further, we realized that just hitting the minimum Energy Star goal would not be enough to satisfy the Hybrid brand’s base level of homes. Here are some of our main brainstorming points:
- If we’re going to build an energy efficient home, let’s not stop at 15% better than code, but target 20% – 30% reductions.
- If we’re guaranteeing Energy Star Certification, we need to target greater than 15% no matter what.
- Energy Star is missing some key subjective elements that can not be ignored in Hybrid’s base homes. Things like type of windows and the use of really nasty materials like vinyl.
Below is a chart that we ultimately came up for the entry-level Hybrid 1.0 Energy Star house that includes items we felt any budget energy efficient home should be built to in the climate zone surrounding Philadelphia, PA. It is derived from the build levels chart on the Hybrid site, but focuses only on the base (1.0) level. For comparison, Hyrbid Construction just achieved efficiency levels 70%+ below code at it’s 3.0 build level. Below the chart is a bit more detail on the reasoning behind all of the choices.
Insulation Levels and Type
Insulation levels are a core factor in any Energy Efficient home and one that is relatively easy and affordable to increase beyond minimum standards when building a new home. Energy Star already recommends surpassing their minimums for new construction in their insulation chart targeting people performing retrofits to their homes. Why not follow suit and add a bit more in all new construction homes. It could cost as little as a couple hundred dollars extra in most new homes. If you’re filling your 2×6 wall cavities and 2×12 floor and roof cavities with decent quality insulation, you are there.
In the subjective category, we point out that dense-packed cellulose insulation is Hybrid’s preferred type of insulation. This will add some cost compared to standard fiberglass batts, but it is well worth it for a number of reasons. Fiberglass is not an option for Hybrid mainly due to it’s poor performance compared to cellulose and it’s high embodied energy. Customer satisfaction is very high with cellulose and it goes a long way in differentiating a house from all of the other traditional Energy Star homes out there.
Air Sealing & Windows & Ventilation
These categories are lumped together as we’ve learned in our research during Hybrid’s formation of what typical builders are doing. Most production homes in the US have inexpensive, vinyl double-hung windows. These are too leaky for Energy Star, so people are switching to single-hung which are a bit tighter. The single hung, however are still leaky enough that a builder can simply install an energy star bath fan and set it to run continuously to achieve the ventilation standards of the Energy Star guidelines. Stale air is sucked out and fresh air is simply brought in through the leaks in the windows and the rest of the house. That means that if it’s 20 degrees outside, that’s the temperature of the fresh air being transferred into your home 24/7.
Since poor air sealing can account for over 30% of a typical home’s energy costs (especially if insulated with fiberglass), we we felt that Hyrbid should take this pretty seriously in all levels of its builds. Most Energy Star homes get a $350 air sealing package from their insulation installer that basically includes spray foaming around key penetrations and stud to sheathing connections before installing the insulation spec’ed. Hybrid will do that also, but take it quite a bit further by adding the following:
- Taped exterior ZIP wall and roof sheathing
- Taped OSB subfloor
- Continuous sealant at critical rough framing junctions
- EPDM sill gaskets
- Gasketed interior to exterior penetrations (ie. plumbing stack)
- Foamed, caulked and taped Window & Door installations
Casement windows have much tighter air sealing components that do not loosen up over time when compared to double hung. They also have a more contemporary look while allowing more light and ventilation into the house. Now that the house is so tight, Hybrid will add a Heat Recovery Ventilator for about $500 that bolts directly onto the ductwork for the heating and cooling in the house so that unconditioned air is not being pulled directly into the house. A few minor and inexpensive improvements that have a big impact on the efficiency and quality of the house.
HVAC & Water Heating
We won’t go into a lot of detail here, but we want Hybrid to install components that are slightly higher in efficiency than the base Energy Star requirements without breaking the budget.
When it comes to hot water, using either an electric heat pump unit or a high efficiency gas tankless unit should blow away the Energy Star minimums for a few hundred extra dollars when compared to a minimum efficiency tank unit of the same fuel.
Heating and Air Conditioning is best done with a dual-fuel system in a typical home that has gas. A high-efficiency heat pump will handle the majority of the heating and cooling requirement, while a high efficiency gas furnace will supplement the heating demand on the coldest days of the year. Hopefully the increased efficiency of the home’s envelope will allow the budget to recoup some of the premium for the higher efficiency units by allowing a smaller unit to be spec’ed.
Appliances and Lighting
It’s hard to not buy Energy Star Appliances these days. We’ve found the key to going a bit farther than the competition is by spending a lot of time on the Energy Star site pouring through the appliance spreadsheets for refrigerators, dishwashers and clothes washers. Often the smaller, no-frills appliances are much more energy efficient (and cheaper) than some of the more popular large appliances that may just not be needed by the end client. Notice it says “needed,” not “desired.”
Lighting for Energy Star is interesting in that you don’t need to install a single CFL to get Energy Star certified if you make up for it in your appliances. With lighting accounting for over 10% of a home’s energy usage (which will only go up as a home becomes more efficient) this is low hanging fruit. Put those CFL’s everywhere. The end home owner can replace any lights that may really annoy them or add their own lighting fixtures after they move in. By the way, CFL’s come in three color spectrums – soft white, bright white and daylight. Choose your favorite.
Subjective Issues Outside of Energy Star
Energy Star does not cover certain aspects, that we felt were important when forming Hyrbid, to any new home trying to position itself as both energy efficient and sustainable. The biggest glaring omission is water efficiency. It does not cost any more to add low flow bathroom fixtures and Water Sense toilets to a new house, yet it can have significant impact on the total water usage. By reducing water usage, specifically in the shower, you are also greatly decreasing the energy used to heat domestic hot water. Two birds, one stone…
Another category that adds no cost to a new home is using Low-VOC paints and finishes in place of toxic, off-gassing finishes that are used in typical homes. The homes will smell fresher and be healthier for your clients from day one, so there is no reason not to include this with any base Energy Star home. See the American Lung Association’s Health House certification for more on the benefits of healthier indoor air quality if you’d like to go to the next level and differentiate yourself further from other base Energy Star builders.
Last, but not least, we try to limit the use of toxic vinyl products in the home as much as possible. This means using fiberglass or aluminum clad wood windows over vinyl which also increase the home’s value. Another big one is vinyl siding, which is not only toxic, but hideously ugly and cheap in appearance. Try a durable fiber cement product that has a better appearance, includes a 50 year warranty and contains over 25% recycled content. Certainteed happens to make our favorite fiber cement siding that’s available in the US residential market at a very affordable price while also locally made.
Compared to the rest of the wealthy countries of the world, we have been building fairly lousy houses on average here in the US. The Energy Star program is a great tool to affordably improve the standard of new homes, but is it enough? Do you want to be another builder or home owner just scraping by minimal standards that most other countries would accuse of being way too lax in terms of energy and durability? Do you want to risk missing a new target because you’re aiming too close to the goal and only a few mistakes will cost you your reputation or a lawsuit? We all need to work together to deliver higher quality housing that beats standards like Energy Star by a healthy margin, while discontinuing the use of cheap and toxic building practices and products.
Do you have a different viewpoint? Don’t be shy. Share it with us in the comments.