My oven cooks unevenly

One solution is to use a baking stone. There are lots of variations available, from thick ceramic baking trays to pizza stones to bit of tile or stone scavenged from contractors or construction people. The point is, the (well cleaned) stone goes in your oven, and stays there. It takes more time to heat up, and also to cool down - but in exchange for this the temperature is more consistent since it takes longer to change.

People use them to avoid or lessen the effects of the kind of cyclic heating ovens normally use (heats up until it senses the temperature, stops heating until it cools enough to trigger the sensor, heats again) a style of heating which means oven temperature is usually a wobbly average, not an absolute temperature. The stone also helps lessen the effect of hot-spots and areas, since the heating element preheating the stone, lets the stone be used as a sort of secondary heat-distributor... one which collects and distributes the heat more evenly, since it doesn't have the same hot-spots as the original element. Hot spots from the top element might still happen, but the stone helps.

In your case, the heating element on the bottom would have to be buffered through the heating stone to reach the food - so the whole stone would heat more slowly, and more heat would cook the rest of the food instead of just getting the bottom burned.

Some dishes which use a shorter cooking time will cook a little differently, since being in contact with the hot stone means they will heat up a little faster (cookies, for example) - but it usually isn't a big problem, and dishes which cook longer will have time to even the heat back out.

I have the same problem. It seems landlords prefer lowest cost appliances, but as you said you cannot choose. Having the heating element below the oven interior is preferable. In this situation I do two things differently:

1) Use an oven thermometer and check it both before and several times while cooking. In my case, the oven temperature is 50F above the dial, and temperature regulation (between when food is in or out) is poor.

2) Use heavy gauge pans or cooking sheets. Also Pyrex seems to work well. Thin metal baking pans or sheets tend to burn food easily.

Using a baking stone as mentioned by @Megha is also a good idea.

The pan that you use can greatly affect how things cook from the bottom --

Dark metals will absorb radiant heat, while light colored shiny metals will reflect it away. Glass dishes allow it to pass through to the food.

What I would try doing is use something light colored (either aluminium or an opaque white casserole dish) in an upper rack, while placing an aluminum sheet pan on the lower rack to help block the radiant heat.

Depending on what you're cooking, I might also try cooking at a lower temperature to warm through, and then finishing it with top heat only (broil or grill, depending on what your country calls it) to brown it.

My response is similar to @Megha's -- buffering with something.

I suggest purchasing an AirBake pan. You can try cooking right on the pan, I've always had success there. An alternative is to put the AirBake pan on the bottom rack as a buffer, and cook on the middle rack per your usual routine.

Note: I mention the AirBake brand because it's what I know. There might be other similar pans.