How to Bid an ADU in California in 48 Hours Without Losing Margin

A homeowner in Alameda calls three GCs for an ADU bid. All three say they can do the work. The one who sends a credible, itemized number first usually gets the job.

The client is not comparing craftsmanship on day one. They cannot see it yet. They are comparing who responded first and whose number felt real. The first credible bid sets the anchor. Everyone after that is negotiating against it.

Speed wins the job. The trap is that speed usually costs you margin. GCs who turn a bid around fast tend to do it by guessing high on the risky line items or eating the risk to keep the price attractive. Either way the margin leaks before the contract is even signed.

You can move fast and price tight at the same time. It takes a workflow, not a hero effort at 11pm. Here is the 48-hour version, hour by hour.

The 48-hour ADU bid workflow

Assume you got the architect's plans Monday morning. The clock starts when the PDF hits your inbox.

The whole thing hinges on two facts. The takeoff and the assembly review are where the hours pile up. The owner review is where the margin gets caught or lost.

Where the hours actually go

A manual ADU takeoff on a 750 square foot detached unit runs 6 to 10 hours for a careful estimator. Sub pricing adds a day of waiting on callbacks. Assembly review adds another half day if you are cross-checking every unit cost against past jobs by hand.

Three of those steps are the ones software collapses. Plan takeoff, quantity extraction, and the first-pass assembly roll-up. Reading dimensions off a PDF, counting fixtures, pulling linear feet of wall, matching quantities to your assembly library. That work is mechanical. It needs your time, not your judgment. It is also the part that keeps you up the night before a bid is due.

Collapse those three and the 48 hours stops being a scramble. You spend the freed hours on the parts that need a builder's eye: the risky line items and the sub scope gaps.

ADU cost per square foot, and why the number lies

Homeowners want a per-square-foot number. Give it carefully. A detached ADU in the Bay Area runs roughly $350 to $550 per square foot in 2026, all-in with permits and utilities. A garage conversion or JADU can land lower because the shell already exists.

That range is wide for a reason. A 750 square foot ADU at $350 is $262,500. The same footprint at $550 is $412,500. The difference is site conditions, utility runs, finish level, and how far the sewer connection sits from the existing line. Quote a per-foot number before you have priced the assemblies and you are guessing with the client's money and yours.

Use your last two completed ADUs as the sanity check on the assembly total, county by county if you work across jurisdictions. A per-foot number is a gut check, not a substitute for the takeoff.

The 2026 law change that belongs in your bid

California changed the ADU math in 2026, and it shows up as real dollars on your line items. Two pieces matter for the bid.

SB 543 impact fee exemption under 750 square feet. ADUs under 750 square feet are exempt from impact fees. On a Bay Area jurisdiction that was charging $8,000 to $20,000 in combined impact and connection fees, that exemption is a line item that just went to zero. Two things follow. Your permit fee line for a sub-750 unit drops, and the client sees a lower all-in number. Design the unit at 749 square feet instead of 800 and the fee savings can outrun the lost square footage. Put that math in front of the homeowner. It reads as expertise, and it is a reason your bid beats the GC who priced the old fee schedule.

The 60-day deemed-approved clock. California requires ministerial ADU permit approval inside 60 days of a complete application. If the jurisdiction misses the clock, the permit is deemed approved. For your bid this is a carrying-cost line, not a homeowner headline. Sixty days of permit review is 60 days before your crew mobilizes. Price the general conditions and carrying cost against that window honestly. If your bid assumes a 30-day permit and the jurisdiction runs the full 60, you just ate a month of overhead you never priced.

Two law changes, two bid line items. Permit fees down for sub-750 units. Carrying cost sized to a real 60-day clock. Both belong in the proposal, priced, not hand-waved.

Title 24 energy compliance is the other line that moves the number on any California ADU, and it is easy to under-price. The 2026 code cycle puts heat pump equipment and HERS verification in the baseline. Price it as a named line, not a contingency draw.

Before you send the next bid, run your last completed ADU against the Margin Leak Checklist. It is a 12-point pass that surfaces the line items ADU bids leak on most: existing conditions, utility connections, permit fees, and contingency buried in a flat percentage instead of priced by risk. Ten minutes, and you will see the pattern in your own numbers.

The owner review is the margin gate

Hours 36 to 44 are the ones that pay you. The takeoff can be fast and the assemblies can be clean, and you can still send a bid that loses money if nobody reads it as the owner before it goes out.

Read the risky line items line by line. Existing conditions on the connection to the main house. Utility runs and how far the panel and sewer sit from the new unit. Site access for concrete and framing deliveries. Permit fees against the current fee schedule, not last year's. The margin on each assembly, checked against your standard, so no sub-scope came in at cost because someone wanted to keep the number friendly.

Catch a $6,000 sewer connection you missed on the takeoff, and the review just paid for itself. Miss it, and you find it during the job, out of your own margin, on a fixed-price contract you already signed.

Where Baxie fits

Baxie runs this end to end. Plan takeoff, assembly pricing off a California-tuned library, sub scope packages, the proposal, and the estimate-versus-actual tracking that tells you next time whether the number you bid was the number you kept.

Baxie is pre-launch. GCs are on the waitlist now, not logged in yet. If you want a full commercial ADU platform today, that is not us. If you want to bid California residential ADUs fast without leaking margin on the line items nobody double-checks, that is what we are building.

The workflow above works with a spreadsheet and discipline. It works faster with a tool that collapses the three mechanical steps and hands the freed hours back to your judgment. Either way, the rule holds. The first credible bid usually wins, and the owner review is where the margin lives or dies.

Run your last ADU through the Margin Leak Checklist and find out which line items are leaking before the next bid goes out.