Thanks for sharing your insight. I have no idea if the windows come with frames. I assume they're double-paned as they're white vinyl Milgard windows that look pretty new. I also have 2 sets of French doors that have to come out and had hoped to re-use. I guess I need to figure out how much it costs to use old doors/windows versus buying new ones.

To be able to re-use the items, they will have to be carefully demo'ed, cleaned up (nails, screws, caulk, etc. removed) and then they have to be stored somewhere...out of the weather and protected from incidental damage. IOW's, there is a lot of labor & expense involved in just saving the items on the front end and possible/ probable more labor on the final end doing touch-ups, restoration, etc. to make them look new.

It will cost a lot more money to salvage and reuse. A LOT more money. It takes twice the time plus the dedicated storage space.

We have a giant 4 car detached garage, so safe, dry storage isn't an issue. I like the idea of salvaging relatively new and reasonable items, but I balk at paying twice the cost of brand new materials just to salvage old used materials.

I was assuming windows/doors aren't like tech gear that get new innovations every year or two. Thus, I thought they still had a lot of value. We have to pull them out because they're giant windows (more than 5' high and 7' wide?) and we're putting the kitchen there now instead. I believe these are reputable brands--Anderson Doors French doors and Milgard windows--but maybe they aren't worth saving unless they are top of the line brands that justify the cost of careful salvage and then retrofitting?

It does seem wasteful to just toss them but I guess I could always list them for free and see if someone else is able to use them.

Donate to Habitat for Humanity.

Even if I donate the windows and doors, I still have to pay my contractor to carefully remove them, clean off caulk, remove nails, etc. Sounds like unless I want to offer them for free on Craigslist for someone else to demo/remove, it will cost me money to keep them out of the landfill.

Are other items equally difficult to re-use? For instance, we have nice Hansgrohe shower hardware (rainfall head and a separate handheld head, plus all the handles and mounting hardware) in the bathroom that we're moving to the other side of the hallway (long story but it's worth it to get a separate toilet room so my teen girls will be able to better share the bathroom). I think it's about 2 years old as the seller did a bathroom remodel before we bought the house. There's also a Toto toilet I would like to re-use if possible.

Anyhow, it sounds like I need to call my contractor and have him walk through the space and tell me what's reasonable to re-use and what doesn't make sense cost-wise. Thanks all.

Re-using old material always comes with a risk. In my experience it is usually more cost efficient to just buy new ones. Unless you recently just replaced the doors, windows,etc. Trying to salvage old appliances also is up to the skill of your contractor. If he/she can remove the appliances carefully then it can be worth it.

I do not agree with the people saying it will cost "A LOT" more to salvage and resuse things. It's easy for someone who is spending other peoples money (like us contractors) to forget how much certain items actually cost new. If you have a full kitchen of cabinets that is in good condition, that's probably 6+ thousand that can be saved by reusing it for a granny flat. Sure the guys doing the demo don't get to hack and slash and use sledge hammers but if they know how cabinets are installed, which they should or you shouldn't have them working for you, they just have to locate the 4 ish screws per cabinet and remove them. Doing it this way really shouldn't take very much extra time IF ANY, and it will cause less mess, plus you save a couple bucks at the dump.

But is everything worth it? No probably not. If your doors are cheap $100 doors from home depot or something like that, it might not be worth saving them and then hoping that they are the same widths you will need in the other building. But if they are good quality solid doors or some kind of custom, and they are fairly wide standard sizes like 2'8's, 2'10s and 3'0s, it's really not difficult to take out a door without destroying it. Pop the trim, run a sawsall down between the framing and the jamb, and put the door in the garage, easy as!

Windows? Same thing. People talking about it taking so much time to clean things up and reuse them is BS. All of the steps to demo a vinyl window are generally identical whether you are saving it or not. Have your contractor pull them and set them aside, and clean up old caulking off of them yourself if you're worried about a little extra labor. Windows are one of those things that you might not want to try to design the new place based off of what you have sitting in the garage though, so you might consider either not keeping them, or only using them if they happen to fit in with what you want.

The one other CON to consider is matching. Say you save 4 interior doors, then you go to make your additional unit, but you need 7 doors, can you still get the same style to match, or are you okay with them not matching?