Gee, I am so lucky, my house holds together pretty well.
Those stupid pop-up drains, though! If you loosen the rod under the sink and take it out a bit, then twist them just right and gently tug upwards, they cork-screw back out of the drain, allowing all the germs in there a breath of fresh air, so they can begin their assault on the rest of the home. No, I mean, so you can zap them with something harsh, and flush it out. I recommend drano, just don’t bend over the sink so you can watch the gore, the stuff might shoot back up into your eyes.
That holiday in the floor at the threshold (in construction, any gap between materials is a ‘holiday’, why, I do not know) anyway, that would be an anomaly, some part was missing or something. Since the subfloor underneath it all is continuous and installed before the wall and door framing, and is totally independent of the door, it may have appeared that the opening went down to the floor below, but it could not possibly have. Or, for some reason, the flooring was removed to repair a plumbing or wiring problem and not put back yet. Or perhaps Jimmy Hoffa is in there.
Here in California at least, due to the tendency of home-buyers to band together and sue the pants off the builder, stuff like this is rare, although there is a tract not too far from my home where the list of complaints is endless, the flaws are both genuine and significant, it even made the newspapers in a feature article. The builder, of course, filed bankruptcy. Really bold flaws, like toilets not hooked up to the sewer line, stuff like that, so unbelievable, if you saw it in a movie it would be ridiculous.
The worst design flaw to me is ABS (plastic) plumbing drain pipes, you can only take them apart with a hack-saw and then replace the whole thingy. Once my dear daughter dropped her heirloom opal necklace down the sink drain, it took me a hundred years to get it out.
Of course, here in California, our only design headache is earthquakes, no severe weather, no freeze-thaw cycles, very little heavy rainfall, no snow loads, just lots of sunlight to keep out.
Everybody should move here! Bring water, please!
Dan the Public Booster