You can also look into programmable thermostats!

While there are pros to the Nest, there are other options out there that offer more features and better home comfort control.  The Prestige IAQ from Honeywell is a fantastic option. 

The Prestige is a feature rich, internet capable thermostat.  It has a large, full color touchscreen display.  Homeowners have the option of downloading the Comfort Control App from Honeywell at no charge; so it can be controlled from any phone, computer, or tablet.

The Prestige can also eliminate the need for a seperate humidistat to control the humidifier.  It has wireless outdoor sensors, so the temperature and humidity is monitored indoors and out. 

The Prestige has built-in Delta T Sensors.  These sensors monitor the temperature rise and drop of the HVAC system and will alert the homeowner with an email if there is a need for a service call.  Service reminders can also be programmed in to email the homeowner when it is time for annual maintenance, filter changes, and humidifier pad changes.

The Prestige IAQ is the choice for our company when a homeowner wants to upgrade to an internet capable, smart thermostat.

Oftentimes the attic is the place to start.  Make sure you have plenty of ventilation, both intake and exhaust.  Check the soffit cavity to make sure you it isn't clogged with insulation.  There are formulas for Square foot of attic in relation to ventilation.  If you have a vapor barrier in the ceilling a ration of 1:300 sf is ok, otherwise about 1:150 is the rule. Second, check the insulation.  All air escaping into the attic should be sealed using spray foam or other sealants. Next, depending on your geographic location, make sure you have plenty of insulation in the attic.  Finally, something as simple as installing blinds over windows can be an economical solution to saving on energy costs.  As recommended in some of the other answers, an energy audit or getting advice from any number of qualified professionals that are willing to visit your home is the best place to start.

http://www.houselogic.com/home-advice/tax-credits/how-to-collect-tax-energy-credits/

I do not believe that would qualify. Only the materials qaulifies for the credit.

Most states do have a 3 day right of recison. This allows a customer to cancel a contract without any penalties and or fees within 3 business days of contract. However in most cases that rule does not apply and the law does not apply if you have invited the contractor over and or if you have gone to their place of business. This law was put in place for the high pressure door knockers. 

Again if you set up an apointment with a contractor and invited them to your home the 3 day does not apply.

That said if there is a real good reason, car accident, unforseen expsences etc. most contractors will allow you out of a contract even if after 3 days. 

Lastly please keep in mind usually 30% of the cost of the job is actually before the job has started, marketing, commisions, adminstration etc. etc. 

I hope this helps.

Tim Brown RGS Exteriors and Contruction

www.utahgutter.com

801-280-3110

Insulation may not be the only thing you need.  It is also important to have air flow through the attic.  this is best accomplished by eave or soffit venting and ridgevent.

According to most building codes, you need one square foot of vent area for each 150 square feet of attic floor space. The minimum is one square foot for every 300 square feet of attic floor space if there is a vapor retarder or the space is balanced between the ridge and intake vents. A balanced ventilation system means about 50 percent of the required ventilating area should be provided by exhaust vents in the upper portion of your attic with the remaining 50 percent provided by intake vents.

R-49 also ventilation is very important to have soffit vent as well as roof vent to keep the attic cool and dry.

Great insulation plays a key factor in energy savings. There are many different options available to increase the energy efficiency of your home.  James Hardie Siding is specifically designed for the climate in which it is installed. Whether you live in a climate with freezing temperatures, snow & ice or a climate with high humidity, heat, and rain; James Hardie has a siding product built for your homes specific needs. Technology has changed tremendously over the years so homes built 15- 20 years ago may have been installed with what was considered cutting edge at the time. Window replacement and the new technology that windows have now can save a great deal of energy costs. A good product that we can recommend also would be the Mezzo Vinyl Window or Integrity by Marvin Windows. These are high performance windows that are engineered to provide outstanding energy efficiency. Major appliances such as heating and A/C units can also offer great energy savings. 

The energy efficiency of a home relies on several factors. 

The most dominant of these factors is the insulation used, both within the perimeter walls and attic.  This would include the houses ability to breath as well as maintain a good barrier.  It's not so much the amount of insulation as the type and installation methods.

Another factor that effects the energy efficiency of your home is your windows and doors.  They come in all varieties of energy ratings, and are also reliant on the installation methods used.

The third thing that I would look at is the ventilation of your attic.  If your attic has the necessary ventilation needed it can reduce energy cost as well as prolong the life of your roof system.

Insulation is insulation regardless of type.  Whatever the R-Value per inch of the specific material is, times the number of inches, will equal the total R-Value.  We are looking for R-49 to be Energy Star. 

If the roof is not vented or we are talking about a hot roof deck, that is another consideration. 

The floors in your home, while insulation will certainly mitigate this delta, will be different temperatures as the laws of thermodynamics are universal. 

Get the insulation in the attic to R-49, seal the ductwork, seal the top plates, etc. and you will be good. 

I think the plans are a good idea especially for older homes. Making sure you change your filters regularly is by far more important.

I really noticed a difference in my electric bill when I put in a programable thermostat for my HVAC. I tend to keep the air down low and would forget to turn it up when I went to work. The new thermostat does that for me. 

I agree with Lane. There are maintenance companies that can services your entire Hvac system at a low cost so you keep the life of the units.

How many kW is the house going to draw?   Generac probably has the biggest market presence but if were going big, Kohler, Onan, and Cummins are great.