I think that the best source of information like that would be a local real estate agent who is familiar with your neighborhood.

Yea, but I don't have one on speed dial.... I would feel really weird cold-calling someone and asking something like that when I have no intention of listing my house anytime soon. Isn't there some kind of rule of thumb for valuation? I will say that when I toured homes in this area, it was a split between yes and no; more of them did have a toilet in the basement, but they were finished basements for the most part.

Hi. i think a basement bathroom would serve you well… especially if theres a functional office… scale down the costs in any way you can… keep it very minimal and small

But no one on this forum knows the market in your area. Call the largest RE offices in your area and just talk to an agent or two. Be upfront that you won't be selling your house. A good agent will be happy to talk to you without expectations. Good agents live by networking and referrals, and knowing the properties and people in the neighborhoods they service.

While no one on this forum knows your local market, and multiple people have suggested contacting a local real estate agent, I think you can safely assume that the value added will not be significant. But it could add to the value of your life dramatically. Might be worth the cost (especially at the low end of your range) just for that.

Exactly. If you are not planning on selling anytime soon, a bathroom downstairs will be a convenient addition for you.

Would there be a way to add a window?

Do it while you have the chance. You will be very glad you did. We did this when finishing a basement because of recommendations on this forum, and we used it all the time. It made it a better family toom/tv room for teenage kids having sleep overs, when we had overnight guests they were able to stay down there comfortably, too. If you have the space to make the footprint a bit bigger, I'd consider making it a full bath, the cost to add a tub or shower is very small once you're doing the plumbing. We fit a full bath into an 8x5 space.

Yes, but only if your basement space is clean, dry, and a pleasant place to be. Avoid making the bathroom so cramped that it's unpleasant to use. I think a half-bath is sufficient, but if you include a shower/tub, set it up so it can be used as a dog-washing station (at its most simple, a walk in shower with a hand-held shower head).

For a "basement" to have a real value it needs to have light, to have an egress, and to be dry.

Have you thought about an excavation for a stairway? 1500 sq feet, that is livable, would add value to your home. And, then, yes a bathroom would be an added plus.

Without getting into re-modeling the basement, there's only one spot I can envision a small bathroom being easily put in, which is a walk-in closet. It's not super-small -- I had a folding table and computer set up there for a while I was working from home, and I've since converted it back to a storage room. I'd say there's enough room for a toilet and small vanity but no shower.

I put a toilet in the basement in my other house, and it was a good move, especially since that house only had one bathroom, and it wasn't a large expense. The problem with this house is we're on a septic so I need a sewage pump, and from what the plumber said, it's at least $5K for just the toilet and associated plumbing, and in my mind that's a lot of money just for convenience for those times we're down there. But then again, you can't put a price on convenience.

No worries about cold calling a RE agent with your question. I've done it, gotten good feedback, and they are happy to have the contact/PR.

For me, the expense and technical issues wouldn't be worth it. Going upstairs to access one of two BRs would not be so physically strenuous that I would want to avoid it, in fact it is good for me!

But, the value to you is up to you to decide.

If the basement has potental to be converted into a pleasant useable space, I would definitely add the bathroom. If you are plumbing for a sink and toilet, then I would also plumb for a shower. Even if you don’t finish the basement, having the bathroom competed will give people an idea for possiblitlites such as bedrooms, den, apartment, etc. I would clean up the basement as much as possible so it looks attractive, even painting if you have to.

Oh gosh no, no excavation! I have plenty of room on the main floor, it's just the two of us, I'm not looking to make the basement livable on a technical level -- it's "livable" enough for us. I'm just trying to balance the value of the convenience for us vs the added value should we ever want or need to sell.

I would not bother with the cost unless it's something you find yourself needing often so it would be for your own benefit (with no expectation of recouping the cost on resale--if you do, bonus!) We looked at a number of houses with basement toilets (sometimes without even an accompanying sink?!?) but no actual living space downstairs, and it always struck me as really strange, like they just really needed a second toilet but couldn't find anywhere in the upstairs footprint to fit it in--definitely not something I saw as a selling point. But agreed, if your basement office could easily have egress added and gets natural light so it could be a bedroom someday, then there might be value in having a bathroom there too. I'd be inclined to do that all as one big project though rather than putting in a bathroom now as a "what if" option.