The living room of the self built house is 3 8 meters high, 4 3 meters long and 4 1 meters wide, and

It's better not to, the distance is too long, it's not safe at all. If possible, a roof is poured directly with concrete. If you use prefabricated panels, you need to put several beams to connect the prefabricated panels.

There is no regulation for this, it depends on the design of your house, there are single doors, mother and son doors, and double doors. There are many double openings in rural areas, and there are many single-door doors and mother-in-law doors in villas. >>>More

In your case, now the general TV wall is replaced with wallpaper. Can you think about it?

It's okay not to set it, because there is a direction that is 5 meters smaller, so it's not a big problem if you don't set up a beam. >>>More

The living room of four pieces is 5m wide, and it is better to leave about 3 and a half meters of long windows.