@Jisa:

" I desired for a flat which should be closely attached to nature. "

Enclosing the balcony with windows would defeat that purpose. Windows will block much of the air movement you and your plants would typically enjoy on your balcony and windows will decrease the amount of light your balcony plants receive. (Some light will inevitably be reflected away from the plants.)

Before going the window route I would suggest the following:

1. Determine which plants the birds are "eating". The solution may be as simple as not having those particular plants on the balcony. Note: I have noticed that young plants just sprouting are the ones birds will nibble on where I am. Older established plants are almost always ignored.

2) Keep in mind the time of year. You didn't mention what country you are in and that can make a difference. The only "Edmontons" I have ever heard of are in Canada and the UK. If you are in one of those cities, you are coming out of winter. (Actually, I would expect the Canada one is likely still in the grip of winter despite what the calendar says.) If so, then that may be the issue. I have noticed that during the spring -- especially early spring -- I am much more likely to have issues with birds nibbling on my balcony plants. The reason is simple -- there are not enough natural food sources available at that time. (Wild plants are just "waking up" or germinating and the insect populations have yet to rise. [The winters here kill off almost all the adult insects so only the eggs or larvae overwinter and it takes time for them to grow up enough to be bird chow.]) Now once the land has fully "awakened" (late spring/summer) and wild food sources are abundant, I find the birds no longer bother nibbling on my balcony plants.

Also note that this time of year, some birds may not be eating your plants so much as harvesting pieces of them to use as nesting material. Once we're into summer, that will no longer be a big motivator for them. If interested, you might leave things like hair pulled from your comb or hair brush, fur brushed from your cat/dog, or dried plant clippings/dead leaves in a shallow bowl/pot on your balcony. If you do so, you may see birds stopping by to carry away such convenient nesting materials.

3. Are there certain plants/pots in which the birds seem to want to nest? If so, then you could allow them to do so -- but make sure the pot is either hung or sitting securely so that it won't tip easily. If you don't want them doing so, then you could try inserting a number of bamboo skewers (like those people use for grilling small pieces of meat like a shish kabob) into the center area of the pot(s) pointed side up.

So as to suggest indoor plants for you, I initially need to discuss light, since that is the thing that will determine what plants can live in your home. Houseplants are classified as low-, medium, and high-light