All the answers posted are good ones, but the truth is that green technology costs more than the existing mass produced counterparts. For example when we install a higher efficiency rating A/C condensers in our developments we spend 25% more than if we installed the min code requirements. Generally the savings can be offset over a period of 3-5 yrs based on how good is the insulation of the structure. The next big ticket is insulation, foam insulation clearly has a higher R value than fiberglass if properly applied, but again a higher cost to the developer. I would say that LED lighting pricing has gotten more reasonable and adequate substitutes can be found at reasonable pricing. Also the use of recycled materials is limited as to the nature of the structure and the geographical area where you would like to live in. South FL due to the abundance of termites and tropical storms make for wood structures not the very best option, hence limiting the viability of recycling old timber.
In brief there are no free lunches in this industry, as better construction methods keep being developed and building codes amended, mass production of new systems will with time lower their price and make them more affordable. Meanwhile there are a significant number of small project one could do to an existing structure to make it more efficient in energy conservation and hence more green.... more