outside drain system

I have to lay new drains underground for some roof rain , kitchen drain and an outside drain/trap but can I connect directly to inspection chamber without smell

Surface water(rain) and foul(poo) are not normally allowed down the same hole in the ground. Check with your local Building Control Dept.
If you don't know about traps and how to run drains, I suggest you do some reading in the local library. It has to comply with Building regulations. Not the science of the moonly rockets, though you'd think so , the way people charge for it!

thank you