What do you mean "hidden costs" of rehabbing a house?
I know many people watch the remodeling shows on TV, like "Flip This House" or really anything on HGTV. But, these shows don't take into account the "deferred maintenance" or what I call "must-fixes" when starting rehab. Not to mention how much it will really cost.
Tearing out the bathroom to make it brand-new and beautiful? Well, when your contractor or tile guy rips out the old tile and backing, he will most likely find some or a lot of wood-rot. The wood that frames the walls, floors, and ceilings of your house become damaged over years of leaks, drips or water of any sort touching it. It's inevitable. So, add on to your budget to replace that now. Not doing so now (while the wall is open) can lead to further and much more expensive damage later. And, importantly, if you are selling your house, you MUST disclose that there is damage because you saw it. It could lead to a big lawsuit later....
Houses shift and settle over time. Some houses have more severe problems than others, depending on the soil, slope of the lot, proximity to earthquake faults, etc. If you decide to replace some flooring and come across cracks in the slab or severe sloping in the raised foundation, please don't just lay the flooring down over the problem. Get it fixed! Again, it will lead to more expensive damage down the road. And again, it become a liability issue if you don't fix it.
Leaks, Infestation, Outdated Electrical
Must-fixes also include repairing any leaks in the plumbing or roof, getting rid of any infestations (termites, rodents, bees/wasps), and repairing any electrical that is a fire-hazard.
You get the picture. When you are rehabbing a house, usually looking at only the aesthetics, you can easily forget about deferred maintenance. And it can be costly to fix and even more costly by not fixing it.
Do you have a house that needs to be rehabbed? Don't want to gamble on the potential hidden costs of rehabbing?