If he did the work according to the contract properly, the wall should be sound. I see no mention, however, regarding the floor construction. Assuming it to be a tile floor, proper terchnique would be to install a pre-slope BEFORE installing the Chloroloy liner, protect the weep holes with pea gravel or spacers, then install the final mud bed with proper slope to drain. If, for example, there was no pre-slope or pebbles protecting the weep holes, water will collect on the liner and become stagnant. This will not, in and of itself cause a leak...just begin to smell, grout on the floor and/or around the drain will stay wet. Now, IF he attached or nailed the liner low on the walls or anywhere on the curb except for the outside face, this could compromise the integrety of the pan and cause the problem you have. Watch for persistant moisture particularly near the drain...it's a red flag. Additionally, there could certainly be a problem with faulty plumbing...more likely if only the wall with the controls is wet. Remove the cover plate, as Mongo suggests and use a light to see if there are any wet fittings there. You might try removing the shower head and temporarily cap the pipe, turn on the controls to pressurize the system and look for leaking pipes or junctions. As I mentioned earlier, easier and cheaper to cut a hole on the other side to better inspect. Drywall is easy to fix... As to your question regaring types of tile, makes absolutly no difference...and grout is not waterproof. The tile is there for one reason only; to make it look pretty, not to waterproof anything. The proper construction is what provides water integrity. With a properly built shower, you can use it safely with no tile at all in place.

I agree with Energy Rater LA. Keep the bathroom door closed. Some people do this all the time anyway. Draw permits on any work in the future. If the bathroom remodel is discovered and the inspector insists on inspecting it at that time, fine. Respectfully do whatever you need to do at that time. If you need to pay a fine, pay; tear out work, do it. The difference between coming clean now and going in to the building department, admitting the error, and doing whatever they demand now and what I suggest above is: 1. Inspector may not see or care about the bathroom when in to inspect future work. In that case, you saved the trouble and cost of fessing up on your own. 2. If you have to tear the bathroom out in either instance, at least you are doing it later if you don't fess up. You got more "use" out of your materials and you get to replace those materials with ones that are more modern and in the "style" of at least a few years later if you wait for the inspector to find it.

The challenge, especially in bathrooms, is that fixtures have a huge range in price. For example, you can buy a serviceable toilet for $100 but if you want a lid that automatically raises and lowers, heated seat, mood lighting, and Bluetooth connectivity then the price runs into the thousands. While it's beyond me why anyone would want a toilet with a remote control, they exist and illustrate the complexity in pricing a bathroom because similar choices can be made with every fixture and surface. If you are going to bring contractors for a bid, then you need to have a pretty good idea what you want so that you can compare apples to apples. Another idea might be to try a local home center. Most offer free design services and while you're not going to get a world class designer and your fixture/surface choices will be limited to what the store sells, it's a place to start. Unlike regular contractors who don't get paid to give estimates, the folks in home centers do.

We generally prefer historical cost basis over any time of assessment, so what you paid for an item. However, one problem with the historical cost basis for ad valorem taxes is it adjusts for realized gains and losses while not adjusting for holding gains and losses. This means that two identical houses would pay two different taxes based on the last time they were sold. This isn't quite fair so to remedy this, ad valorem taxes are occasionally adjusted to compensate somewhat for holding gains and losses. In other words, we don't want people who bought 3 acres next to Central Park 65 years ago, to be paying property taxes on $100,000 when an identical property next door pays taxes on $15,000,000. That is the entire purpose of adjusting property values. Improvements aren't simply holding gains, it is putting money into the structure so that it is nicer. If you want to fairly tax improvements you would need a tax on the increased value less a tax credit the amount paid over the marginal assessment value. So, the premise that you have some moral obligation to pay marginally higher taxes because you spent $50,000 for a nicer kitchen that adds only $20,000 to the property value, is one I find questionable. In other words, if you paid more for the remodel than it added in property value you should get a tax credit against the increase. However, that is far too complicated and thus taxing jurisdictions who are acting efficiently and attempting to be fair, avoid increasing valuation for improvements and replacements, but do increase valuation for additions. Now this is completely different than rules that allow select groups to avoid assessment for holding gains and losses.