What is a zero energy home?
A zero energy home is a home that produces same amount of energy as it uses.

How is this done?
This is done by building a very tight well insulated home.
Next is to take advantage of the natural resources such as; solar, wind, and hydro power.
Passive solar is incorporated into the design of the home.
Efficient appliances are selected for the home.
Efficient lighting practices are incorporated into the home.
Efficient heating and cooling are also used.

All of this is taken into consideration during the planning stages of the home.
A tight well insulated home.

There are three ways heat will leave your home. The first is conduction heat traveling through the walls. The second is by air infiltration. That is air leaking in through the cracks and opening in the home. The third is radiant heat. Radiant heat is why sun light feels warm. Most homes wall are constructed with 2x4, or 2x6 stud construction, with fiberglass insulation in between the studs. A 2x6 wall with R-19 insulation has an actual over all insulation value of R-15. The reason for this is that the fiberglass insulation has a higher R value than the wood studs. What needs to be done is to provide what is called a thermal break. By providing a thermal break will reduce heat loss. Fiberglass insulation also allows air to slowly leak through it. To help reduce air leakage a vapor barrier is installed under the drywall.

Better walls.
Easiest and also the least expensive method of improving the insulation value of a stud constructed wall is to add foam sheets to the outside of the stud wall. This foam can be from 1 to 2 inches thick. Polyurethane foam could also be used instead of fiberglass insulation. This can also be done on existing home when replacement siding is installed.

The second method is to stagger the 2x4 studs in a 2x6 wall. See picture below. The illustration on the left shows how the studs are staggered in a wall to provide the thermal brake. The pink is the insulation, and the yellow is the wood studs. The gray is the drywall. The down side of this type of construction requires more wood to build. The outside could also be covered with a foam sheets instead of OSB, or plywood.

Then there is the Structural Insulated Panel, or more commonly call SIP. This is the most common construction material in a zero energy home. It offers some of the highest insulation value, with lowest air infiltration. A SIP panel is two sheets of oriented strand board (OSB) with rigid foam glued between the two panels. The SIP comes many sizes 4 by 8 feet, and as big as 9 by 28 feet. Panel thickness is from 4 1/2 inches to 12 1/2 inches. These can have R values as high as R-45. They do have greater structural strength than conventional stick built home. Foam can also be attached to the exterior of a SIP to increase the R value even higher. Since all joints on a SIP panel are glued together this results in reduce air infiltration. The inside is finished off with drywall.

Basement walls are well insulated. There are different methods of doing this. One is to add foam panels to the exterior of the basement walls. The second uses hollow foam blocks that interlock to form the walls. This is like building with giant Lego blocks the basement walls. Next concrete is poured inside the foam blocks to give it structural strength. Basement floors or a floating slab has foam sheets installed before the concrete is poured over it. This is all done to help reduce heat loss into the ground.

Good quality windows need to be selected for the home. This is because a window has a lower R value than wall. It may also have surfaces that open to allow for ventilation. Windows need to seal properly in order to prevent air leakage. Total window surface on the north, east, west walls should be kept to a minimum. This is because during the winter sunlight does not come in the north windows. The types of windows you want are double low-E glass in double or triple pane. Check the rating sticker that is found on the window. Don't get metal framed windows. Metal clad is OK. The windows on the south side of the house should have a high solar heat gain value.

Passive solar can be implemented into the design of the home. Passive solar is using the sun energy to help heat the home. More window surface is installed on the south wall of the house in order to take advantage suns’ warmth. Overhangs also prevent light from entering the home during the summer, but allow the suns light to enter during the winter. Thermal mass is built into the house to help regulate the temperature. During the day the thermal mass absorbs heat, and releases it during the night. This helps reduce day to night temperature swings. It's recommended to hire an expert to design a passive solar home.

Energy star appliances are selected because of their lower energy demand. Old energy inefficient appliances are replaced to help reduce electrical use. By examining the appliances’ energy label you can determine there typical energy usage. This can help you from making a costly mistake. Example: Front load washing machines use less water. They also they spin the laundry at speed over 1000 RPM. This removes more water out the fabric. Thus reducing the time required to dry the fabric. It is also wise to avoid high energy demanding electrical loads such as hot tubs.

By taking advantage of natural day lighting to provide for some of the home lighting needs. This reduces the need for supplemental lighting. Installing compact florescent lights, or LED lights will also reduce electrical demand.

Heating plants should be very efficient. Solar hot water system can be used in most climates to help reduce your water heating needs. But you will still need a backup heating source, because their can be long periods of no sun in the winter. For the hot water a tank-less hot water heater is a good choice. This is because a tank-less hot water heater has no standing heat loss. A geothermal heat pump can be used for home space heating and cooling.

Will a zero energy home work in cold northern climates? Yes, they can. True it's much more difficult to achieve zero energy usage. But it can be done. Not every one can afford to build a zero energy home, but some the elements can be implemented in new home construction. Some are relatively inexpensive implement, and are easy to do.