Energy efficiency

Aside from providing our 9 year-old with her own bedroom, and connecting the house to our back yard, a key objective of this renovation is to increase the energy efficiency of our house. We looked at fancy stuff like geothermal heat pumps and photovoltaic solar, but all those technologies are evolving rapidly, and now doesn't seem like the best time to invest. So, we're planning for what I'd call conventional "best practice" energy efficiency:

• No central air conditioning
• No fireplace or internal chimney
• Exterior 6" walls and attic insulated with Icynene
• Efficient double-pane low-E windows
• Hydronic baseboard heating, one zone per module
• High-efficiency, modulated-flame, condensing gas boiler
  
• Tankless gas domestic hot water
• Compact fluorescent and LED lighting where appropriate
  

After this renovation, our next energy priority will be to upgrade my commuting car to all-electric. By the time that's done, thin-film photovoltaic or other distributed-generation options will be available, and we'll look to make our next step.