Answer: Um, I actually wouldn’t, unless you are skilled at working with the runes and have a solid relationship with them. Of course, one can mark individual runes on vulnerable points of the house like mirrors and windows and derive some benefit from their latent power, but to truly reap full benefit of everything that the runes are capable of in defense of a home, one has to be experienced at interacting with them and navigating the endless push/pull, give/take of that relationship. Relying overmuch on them without that relationship already established can actually be rather risky. I was taught by a very, very skilled rune-master and even I won’t use them randomly in spells. It costs too much.
Why do I caution against the use of runes in a house charm, you might ask? Because if you are passively or incorrectly using the runes (i.e., if you are not feeding them in the way that they like but are expecting or demanding their protection, or power in fueling wards), and a rune worker comes a long who is willing to feed them, and moreover who has been feeding them regularly and therefore who has a tight working relationship with them, he or she can call them away. This means that if your house shields are dependent primarily on runes, and you’re not in active right relationship with them ( as my teacher once defined it to me), a rival magician can make an offering to them, call them away, and the mercenary little bastards might just abandon you leaving the shields to collapse. After all, they’re good independent contractors: why should they work where they’re not being paid?
So….unless you are an experienced rune worker, at most, I’d only use them passively to augment already solid house shields and protections. I might incorporate them into a door ward, or a mirror ward, but I would not use them as my primary method of defense. If you are an experienced rune worker, then you don’t need me to answer this question!