So 15% down may be needed to hit that mark. 

The waterfall on either side makes the space kids friendly (no abrupt sharp edges).

For reference I would have only been able to rent the space for about $900/month.

BiggerPockets is launching a new platform for exactly this early next month and you can get signed up to receive information about PassivePockets here I know this all sounds like a BiggerPockets ad, but really I wouldn't be here if BiggerPockets hadn't helped me SO much on my own investing journey and I can't help it that I think we build the best tools and give the best education in the real estate investing space!

I am not a pro in that space so I may be wrong but that is not what I am seeing. 

This is a Maryland Historical Property, zoned for residential high density, with specific limitations on its usage due to its zoning.The property is massive, offering 8,276 square ft of space, including 5,445 square ft of finished area, and it features a substantial driveway.

While it’s true that ADUs might reduce yard space or parking, the additional income stream easily offsets these downsides.6.

If this isn't a separate dwelling unit you can't take losses from the rooms / space you are renting and use them to offset non-passive income (Section 280A of the tax code)Rental expenses are limited to the amount of your rental income and the balance of rental expenses is carried forward. 

I don't drink but the local KREE Holiday party had nothing but 4 roses, Woodford, Makers Mark, and bourbon in every Secret Santa gift.

which seems rather 'overpriced,' for an REI venture with a handful of people or less (in most instances) using the data lines and server space, etc.