How fast are the i-houses produced?

I have a dilemma. I just had an offer accepted on some property that I was buying specifically for an i-house, and I have 10 days in which to complete my due diligence before signing the papers. I just found out that according to our land use laws I have to have the i-house IN PLACE by August or I will have to pay for a new conditional use permit. This will cost, minimally, $6,000.00-and even with that amount of money the permit is not guaranteed. Can an i-house be completed in that amount of time? This would include getting the plans for it to the county and having them approved. I live in Oregon-not a great shipping distance-maybe this helps. I am very frustrated right now. This was my dream and because the sellers real estate agent did not inform me of the short amount of time I had which to replace the mobile I had I am afraid I can't get this done. Thanks, Carol