Budget for unforeseen repairs. August suggests to build in a generous contingency to your budget for for any potential unknowns. "You will not be able to see everything at the inspection. Once you start demolition, you may discover hidden damage—from age, insects, moisture, etc.—that should be addressed while you are renovating, as it will only be more expensive and disruptive to remedy later."   Photo 12 of 32 in Before & After: A Historic Tribeca Townhouse Gets a Magical Makeover