When Building An ADU Can Go Wrong
Most homeowners think building an ADU is expensive because of construction costs.
That’s not actually what destroys the budget.
The real killer is bad planning before construction even starts.
I’ve seen people lose:
4–8 months in permitting
tens of thousands on redesigns
huge amounts on utility relocation
money fixing grading/drainage mistakes that should’ve been caught on day one
And the craziest part?
A lot of contractors still bid ADUs without properly analyzing:
setback limitations
sewer connection distance
electrical capacity
soil conditions
access logistics
parking impact
foundation compatibility
That’s why two identical-looking ADUs can have completely different final costs.
One finishes smoothly.
The other turns into a financial bleeding machine.
The homeowners usually blame “construction pricing”…
…but most of the damage started long before the first shovel touched the ground.
ADUs are becoming one of the smartest investments in California right now — but only when the planning phase is done correctly.
Most expensive mistakes in construction happen in silence before construction even begins.