From greenbuildingadvisor.com article HERE
Insulation, Air Sealing, & HVAC Offer Chances to Slash Energy Bills
Reductions of 50% to 90% are attainable
Superinsulating a home can radically improve the energy performance of an old house. These so-called deep energy retrofits achieve household energy up to 90% by addressing all (or nearly all) energy loads — space conditioning, hot water, lighting, appliances, and plug loads — and sometimes even transportation. Energy reductions of this magnitude require an intensive and extensive systems approach: The inherent relationships among energy, indoor air quality, durability, and thermal comfort must be honored throughout design and construction. Passive solar design and renewable energy systems are common in these projects.
Careful planning is required for this extensive and invasive green remodel
A deep energy retrofit can significantly reduce household energy consumption, but only as long as nothing is overlooked. Space heating and cooling, hot water, lighting, appliances and electric loads in general should be considered as part of the retrofit.
Current energy use is the key to improvements
You can learn how your house handles energy in a number of ways. Studying utility bills covering at least one year, and preferably more, is a good start. Blower-door testing, infrared imaging and duct-blaster testing offer valuable information about current energy consumption. An energy feedback device, such as the Energy Detective, measures electricity usage and can be useful. An assessment of existing conditions also should include a look at how the building envelope gets wet and dries out, and how energy improvements may affect where this moisture goes.
Energy improvements can affect moisture performance
A deep energy retrofit probably will include changes to the entire building envelope as well as heating and cooling equipment. Moisture must also be carefully managed; this may mean adding perimeter drains in the basement. Exhaust fans in the kitchen and bathroom, or a whole-house ventilation system, where those features are lacking play critical roles too. Plants and roots that are too close to the house may have to be cut back to encourage drying outside and open up the house to get more sun. In some cases, both the site and the structure should be examined with an eye toward adding rooftop- or ground-mounted solar-energy installations, solar hot water collectors, or a wind turbine. With a sharp reduction in heating and cooling loads it might be possible to downsize or even eliminate some heating and cooling equipment.
Don’t throw away the old stuff
What about building materials that might be replaced during the project? Cabinets, trim and flooring might be used elsewhere—in a basement or workshop, for example. Wood, gypsum drywall and other processed materials could become soil amendments or a base for a driveway or sidewalk with some planning.
Smart project planning can cut remodeling trauma
The stages of a project can make it easier to live through. Most of the living spaces will probably be involved, so if you're planning to remain in the house while it's being retrofitted, it’s important to figure out what you will need to use and what you can put up with. Disruption is significantly less when the project is tackled starting from the outside of the house. Approaching projects from the outside also makes it easier to keep the insulation andair barrier continuous.