The size and quality of foreign teacher housing depends in large part on the fiscal resources and facilities of the institution where you work. Older institutions tend to have older facilities, although renovations and new construction are the order of the day in schools all across China. Schools in smaller cities, or in suburban locations, tend to have better and more spacious facilities than large urban-centered campuses, largely due to differences in the cost of land and materials. There is no question that your accommodations will be less comfortable than those you may be accustomed to at home. Even in the newest, best equipped apartments, you can expect some problems.
Electrical problems are common in many locations, as are occasional shortages of hot water and heat.
Your host institution will go out of their way to make sure you are as comfortable as you can be within the limits of their capabilities. Perhaps the most important thing to remember, whatever your particular situation, is that your Chinese colleagues live under even more difficult circumstances. You will be afforded the best your school can provide.