If I wanted a backyard guest house, how deep would my pockets need to be?

Yeah, permitting really can sneak up on you. When I did mine a few years back, I thought I'd covered all the bases...then the city threw in some drainage requirements I hadn't anticipated. Ended up costing an extra couple grand and delayed things by a month. Still, I'd agree - if you're staying long-term, the flexibility pays off in ways beyond just money. Just keep a cushion for those surprises.

Yeah, permitting's always a wildcard. One thing I'd suggest is budgeting in stages - first permits and groundwork, then utilities, framing, finishing touches...keeps you flexible when surprises pop up. Saved my sanity more than once, haha.

"budgeting in stages - first permits and groundwork, then utilities, framing, finishing touches...keeps you flexible when surprises pop up."

That's solid advice. From my experience, flexibility really is key, especially with DIY builds. Even the most thorough planning can't account for everything - like the time I found old buried pipes exactly where my foundation was supposed to go. Tackling things step-by-step definitely eases stress and keeps your budget from spiraling out of control. Sounds like you're on the right track already.

"Even the most thorough planning can't account for everything - like the time I found old buried pipes exactly where my foundation was supposed to go."

Haha, sounds familiar...I ran into a similar snag when we started digging for our patio. Turned out there was an ancient septic tank nobody knew about. Definitely agree on budgeting in stages though; breaking it down helped me keep my sanity (and wallet) intact. Just remember to leave some wiggle room - surprises seem to be standard procedure with backyard projects.

Ran into something similar when we did our deck - hit a random concrete slab buried underneath. Took a whole weekend just to break it up and haul it out. Definitely second the advice on padding your budget...you never know what's lurking underground.