Progress on the siding has been slower than I would have expected but the results have been better than I imagined. The main material is a product called TruExterior. It is made with fly-ash, a by-product recovered from coal combustion. The fly-ash is combined with polymers to create an inorganic material that is resistant to moisture and that offers no food source to carpenter ants, termites, wood-boring bees, and other insects. It is being installed as a rain screen (3/16″ open gaps between boards) which promotes drying of the backside. Five different board widths are being used in a random pattern to mimic the different size tree trunks which surround the house and will be painted a shade of grey. Areas that currently appear black will be sided with a product made from rice hulls using horizontal 4″ boards in a contrasting rust color. In total, about 70% of the siding is made from recycled or rapidly renewable materials. Still to be completed are the north side and riverside facades. These should go a little faster since they are not as high and do not require any board splicing.