In Fairfax county you can do a search for permits on an address. I imagine MoCo is the same. Punch in their address and see if any permits come up. If they do, you'll see what they're for, etc..

Dunno re MD, but in VA you only get notices when someone is applying for a special permit (variances, etc.) and neighbors inputs are seeked.

Also, often builders/owners send out courtesy letters before construction begins.

Why does it matter? You go online and look. No, you don't get notice.

Hmmm.. How about asking your new neighbors if anyone else has met the new/future residents?

A house nearby us was purchased several months ago, but the buyer has not yet moved in. We are wondering if perhaps he is actually waiting for permits to tear the house down - we live in a part of MoCo where there are a lot of tear-downs. Would we get notice of such permits, or should we just keep checking the MoCo permit site to see if anything is listed?

(The reason it sort of matters is that we are weighing a decision whether to renovate or move, and if a close by neighbor is about to put a giant house onto their property, it might affect our decision).