I live in a small appartment in Wormer, a village with 10.000 inhabitants 15 km in the north of Amsterdam.
I have the same problems as other radio amateurs in an appartment with their antennas, little space on the balkony.
I use for 20 meter and higher frequenties full size inverted V wire dipoles and end fed antennas, they are in temporary one by one formation.
For 30, 40, 60 and 80 meters I use mobile mfj antennas, they have a lenght about 2,4 meter. The railing of the balkony is big enough for a good ground. The railing is about 6 meter above the ground and the antennas are on a little telescopic mast of 2 meter.