adu renovation pitfalls - garage conversion vs. backyard cottage

Did the garage conversion myself a few years back - definitely cheaper upfront, but you're right about hidden surprises. The concrete slab needed leveling, and insulation upgrades were more involved than I expected. Backyard cottages can be pricier initially, but since they're purpose-built from scratch, fewer surprises pop up mid-project. Either way, permits depend heavily on your city; mine was pretty straightforward. Might be worth checking local forums or city hall to gauge the bureaucracy factor first...

That's interesting about the slab leveling - I hadn't even thought of that being an issue. When you tackled the insulation upgrades, did you end up having to redo drywall or interior finishes too? I'm leaning toward a garage conversion myself (budget constraints, as always), but the thought of hidden costs creeping up mid-project makes me nervous.

I've also heard backyard cottages can have more predictable timelines, but then again, you're starting totally fresh, so there's excavation, foundation work, utility hookups... feels like those could add up fast. Did you find that your garage conversion ended up close to your initial budget, or was it significantly more expensive after handling those surprises?

Also curious - did you run into any zoning or setback issues with your garage conversion? I've heard some cities can be picky about setbacks from property lines or height restrictions, even when converting an existing structure. Wondering if that's something else I should brace myself for...

"Did you find that your garage conversion ended up close to your initial budget, or was it significantly more expensive after handling those surprises?"

Ha, "initial budget" - that's a good one. Honestly, ours went over by about 20%, mostly due to insulation and drywall surprises. We thought we could reuse most of the existing drywall, but once we started opening things up, it turned into a domino effect. Nothing catastrophic, just lots of small stuff adding up.

Zoning-wise, we lucked out. Our city was pretty chill about setbacks since we weren't changing the footprint or height. But I've heard friends in neighboring towns had to jump through hoops even for minor conversions. Definitely worth a quick call to your planning department before you dive in.

Backyard cottages might seem predictable, but like you said, starting fresh means excavation, utilities, permits... it adds up quicker than you'd think. At least with the garage, you've got a structure to work with - even if it comes with some hidden headaches.

Nothing catastrophic, just lots of small stuff adding up. Zoning-wise, we lucked out.

Yeah, the domino effect is real. When I did my garage conversion, I thought I'd save by keeping the existing slab, but turns out it wasn't level enough for flooring. Had to pour a thin overlay - unexpected cost right there. Still, compared to friends who built backyard cottages, my headaches seemed minor. Curious if anyone ran into major utility hookup issues with backyard builds? Seems like that could get messy fast.

"Had to pour a thin overlay - unexpected cost right there."

Yeah, flooring always seems straightforward until suddenly it's not. Had a client recently who went the backyard cottage route, and utilities became a real headache. Sewer line was deeper than anticipated, meaning more excavation, more permits... you get the picture. Sometimes, I think garage conversions dodge a bullet there. Wonder if anyone's had trouble with electrical capacity? Older homes aren't always ready for that extra load.

Electrical can definitely sneak up on you, especially with older homes. Had a project last year where the homeowner wanted to convert their detached garage into a guest suite. Everything looked good until we realized the main panel was already maxed out. Ended up having to upgrade the panel, which meant more permits and inspections - basically added another couple weeks and a chunk of change to the timeline.

One thing I'd suggest is doing a thorough electrical assessment upfront. Checking the panel's current load, breakers, and wiring condition can save a lot of headaches later. Also, consider future-proofing a bit: running conduit or leaving space for additional circuits if you think the client might expand again down the line.

Curious if anyone's bumped into insulation issues with garage conversions? Seems garages are rarely insulated properly, and that can get tricky when trying to meet residential code requirements...

Good points on the electrical - been there myself with our historic place. A few thoughts from my own garage conversion experience:

- You're spot-on about insulation. Our garage was basically a sieve when it came to heat retention. We ended up having to strip it down completely and redo insulation from scratch to meet code. Not fun, but worth it in the end.
- Older garages often have moisture issues too, so watch out for that. We had some hidden water damage behind drywall that we didn't catch until demo day.
- Don't get discouraged by these setbacks though...they're pretty common with older structures. Once you get past the initial hurdles, things usually smooth out.

Sounds like you're already thinking ahead, which is half the battle. Good luck with your project - it's always rewarding seeing these older spaces come back to life.