¿Esto suena natural? It is the light bulb he invented that gives us brightness in our house, allowing us to do many things even at night

The sentence order of this is a bit unusual, but it might depend on what sentences come before it.

Most sentence structures in English have the main subject first.

So I would probably write "He invented the lightbulb that gives us light indoors, allowing us to do many things even at night."

"in our house" is very specific, since it also gives us light in office buildings or train stations or whatever, so I changed that to indoors.

I also changed "brightness" to "light." Brightness sounds more like a setting on a phone to me, like you'd turn up the brightness on the screen. Or it's bright outside. Basically avoiding adding -ness sounds neater in this case. So light sounds a bit better.