is this calculated as a % of something or just a low-side flat $ requirement you've come up with specific to your own personal scenario?

The answers to those questions will help you determine how DIY you want to go, and how much you can leave up to chance.I can't post links here, but for more, please google:"Why you need an experienced ADU builder" - case examples where cities asked for tens of thousands of dollars of work, or flat out would not have allowed an ADU project, except for knowing when to push back"ADU sitework & utility costs: 10 hidden costs" - dozens of costs you need to account for on your ADU project that I promise you haven't thought of and no one else will tell you about"How to find ADU builders" - compares DIY route vs. other options, plus more on what to look for in a good contractor

Front unit i think market price is around 1600-1700, but i am planning for 1500-1550 to gain advantage on rentingit's a popular rental area in trending neighborhood, so it has a lot rental on the market and a lot investorfirst regret is i think my offer was too high, i offered asking price at 224k which with my 10k deposit and no inspection (i did had a long term contractor go take a look with me) i can likely get the house for cheaper, it went from 300k to now 224k from last year, so 8 month on market, i could get it for maybe 200k or 210k insteadOriginally i planned to have some minor interior update include few windows, which i am estimating around 3k, but noticing the 3rd floor shingle siding was aging and looks like just matter of time, so i had to replace 2 more exterior siding that need scaffolding, long story short, my repair cost went from 3k to around 8-9kmy dscr loan is 7.625% 30 years, my monthly would be $1577 PITI + water (say $230), compare to my expected rent of $2430, so $623 remaining each monthsome concerns are1. it's flat roof and it's just matter of time for me to replace2. i know this market is always trending, a lot tenants and a lot rentals, so it's competitive but popular, i dont know what to feel about it, i have other rental in the city, just not this specific neighborhood3. since there's so many investor in the area, why no one bought it for the price, it was once lowered to 256k before it go down to 224k. when the market was hot, i think 324k would easily sold, but obviously it didnt as that's what they listed in 2023 summer4. unit was managed by management company, last lease on front unit was from June 2022-June2023 rented for $1700, then they later put for sale for 324kon one hand i think the number works, but on the other hand, i keep have this feeling i wanted to back out of the offer, i think also due to my saving would be down to 20k after closing and all the repairs made, which i normally wanted to have at least 30k in bank, also the extra siding job got me scared a bit, and roof that need to be replaced in futureif i back out now, i am going to be losing 10k + inspection 800, so that's close to 11k lostWhat's your take on this, i would hate to lose 11k without any valid reason and just scared myself out of this deal, but honestly i am having some hard time looking forward to this purchase.

The reason we bought the property is that there is an 8-acre clearing at the peak of one hill which is where we planned to build the future homesite as it has an amazing view and a nice, mostly flat area (see second picture for a bit of the view).

I want an all flat surface.

So, absent new information, there is little known opportunity for treasury or mortgage rates to decline (it's already baked into long term rates) and only risk that rates will increase if expectations are wrong. 

SECOND BUT - BUT, This is what consumers want, otherwise there would be many more sellers using flat fee discounted brokers.  

Why did the "flat roof" not pass? 

Utilities have been pretty finicky so I finally have everyone moved to a flat fee, which not being on a flat fee caused some hairs to raise with the middle tenant. 

They charge a flat fee per bedroom so it's always predictable.