Preserving and restoring a historic property is one of the most "green" things you can do. Demolition of historic homes for "blight abatement' only contributes to larger landfills. We always try to keep as much of the historic fabric as possible and make sure that we preserve elements of an old house like woodwork and plaster. The less we put in a dumpster means fewer trips to Home Depot and Lowes for 'rebuilding supplies'. I do believe that one should always rewire and use high efficiency heating and cooling with programmable thermostats. We always strive for low maintenece landscaping and avoid lawns ( a real water waster) at all costs.
There is an interesting article in Preservation Magazine that is worth reading.