Soft Costs: The Money You Spend Before Construction

"Soft costs" are everything you pay before and around construction — the paperwork half of the project. Homeowners routinely forget them, then wonder why the budget is $30K short. Plan for these five.

Design ($5K–$20K+). Floor plans, elevations, site plan, and the full drawing set the city requires. Cost scales with complexity and with how much design iteration you want. Cheap plans exist; plans drawn without knowing your lot's constraints get expensive in redraws (Module 2's lesson, again).

Structural engineering ($3K–$8K+). Foundation design, framing calculations, seismic details. Required for new construction and most conversions with structural work. Hillsides multiply this.

Title 24 energy calculations ($500–$1,500). California requires an energy-compliance report proving your design meets efficiency standards — insulation, windows, HVAC, water heating (Module 9 explains it properly). Quick and cheap, but mandatory.

Survey ($2K–$5K, when needed). A licensed surveyor marks your true property lines. Needed when building near setback limits — which, at 4 feet, ADUs usually are. Fence lines lie; surveys don't. Skipping one to save $3K risks discovering mid-build that your ADU sits on the neighbor's land.

City fees ($3K–$15K+). Plan check fees, permit fees, school fees (for larger units), and utility connection charges. Good news: state law exempts ADUs under 750 SF from impact fees entirely, and caps them proportionally above that. Fees vary dramatically by city — one of the reasons identical ADUs cost differently across a county line.

The planning rule: hold $20K–$45K for soft costs on a typical project, before construction dollars. Every solid estimate itemizes them; a budget that starts at "construction" is missing its first chapter.