My husband has a US visa appointment at the embassy in London and I have a question about the documents he needs to bring with him to his interview. I've seen a few different things online about what he is required to bring. I know that he needs copies and originals of his documents, but does he need original and copies of my affidavit of support documents I submitted or just copies?

For other people = CR1 visa application.

Originals of everything he has submitted thus far. The reality is he probably won't need them.

I've asked for your thread to be transferred to the marriage-based visa forum

Since you obviously went through the states for your husband's CR-1 and the I-864 was submitted for approval before it was sent to the US Embassy, then no, he doesn't need a copy of the I-864. It is in the package of documents that NVC couriered to the Embassy. You are correct, however, that he should bring a copy and an original of all other documents. They will ask for what they need and he can give them the copies. Also if there were any originals that you submitted that you would like back, he can ask that the original be substituted with a copy and give them the copy. He would do this during the actual interview, not while he is being seen by the first person.

The I-864 needs to be the original. The supporting documents for the I-864 can be copies.