Why not just leave your house alone? Unless your baby has known immune deficiencies (family history isn’t applicable yet) why spent the money?
If the baby has allergies, they’ll show up and DD/DS will either build immunities to them, or you can take steps at that point.
I have read/heard that pet ownership can actually help a child NOT develop allergies. Also, keeping your house too clean and not exposing your child to germs can make them unable to fight off germs. You have to use the immune system for it to work properly. Of course, it could be that I hate cleaning and these are good excuses!
Creating a “micro-climate” in your house doesn’t solve anything… you eventually WILL go outside!
All this “anti-bacterial” stuff and hyper-cleanliness is actually weakening our immune systems by not letting us get a cold or minor infection, etc. (exercising our immune system), and promoting hybrid strains of “bugs” that are resistant to anti-biotics.
I not saying putting your child in peril here, just let him/her be a kid and get a cold or scrape every once in a while and not medi-vac them to the E.R.!