Contour crafting was invented by a creative genius engineer whose idea was originally focused on constructing molds for industrial parts. He later expanded his thinking to rapid home and building construction to help during storm recovery. Think of it 3-D printing of a home where electrical, plumbing, utilities, custom electronics, and such are installed as the home is "printed" layer by layer and potentially in one day. Precision computer-controlled near-concrete material is applied layer by layer by an apparatus with material feed, various controls for shaping in three dimensions, electronic connections, and for larger applications it uses lattice-like tower elements for support and control of the configuration. Consider a "CC Apparatus" of the appropriate size for contour crafting an industrial building. The initial cost is $190,000 and may be sold in year t for 0.7^t of the original price. Operating costs are $40,000 the 1st year, increasing by 5% per year. Due to the continual site installation and dismantling, maintenance costs such as cleaning, refurbishing, repair, realignment and so on are $65,000 the 1st year, increasing by 13% per year. Interest is 8%. Determine the optimum replacement interval when no planning horizon is specified. ORI = years at an EUAC of = per year.