Every Addition Bid Answers the Same Five Questions. Most of Them Answer Late.
Three quotes for the same addition can come in $80,000 apart, and homeowners usually read that as a difference in greed or quality. It’s almost never either. The three contractors priced three different scopes, because at the quoting stage nobody has decided who engineers the structure, who produces the energy compliance, or who answers the city when the plans come back with corrections. Those decisions get made anyway. They just get made later, and by then they’re change orders. The questions below force them into the open while you’re still choosing.
1. Is the Contractor Licensed, and Can You Verify It in Ten Seconds?
California has a minor-work exemption that lets an unlicensed person take small jobs. As of January 1, 2025, that threshold went from $500 to $1,000, which sounds like it widens the gray area. For an addition, it does the opposite. The exemption comes with two conditions: the work can’t require a permit, and the person can’t employ anyone on the job.
An addition always requires a permit. That single fact removes the exemption entirely, at any price. A licensed contractor isn’t a preference on this kind of project. It’s a legal requirement, and the Contractors State License Board’s own guidance says that if either condition is violated, a license is mandatory no matter what the work costs.
Ask for the license number in writing and check it yourself on the CSLB’s public lookup. You’re looking for three things: the number is active, the classification fits the work, and the name on the license matches the name on the contract you’re being asked to sign. That third one catches more problems than the first two.
2. Who Stamps the Structural Drawings?
This question separates addition contractors more reliably than anything else, and it’s the one homeowners are least likely to ask.
An addition ties new framing and new foundation into a house that’s already carrying load. Somebody licensed has to design that connection and stamp the drawings. If the contractor doesn’t have that person in house, they’ll subcontract to an engineer they’ve worked with before. That’s fine, but it means the structural design happens after you’ve signed, by someone you haven’t met, working from a set they didn’t draw.
The consequence usually shows up at the foundation. Older Los Angeles houses often sit on shallow or undersized footings that were fine for the original building and aren’t adequate for what’s being added. Whether that gets caught at the drawing stage or during excavation depends entirely on whether an engineer looked at the house before the bid or after it.
So ask directly: who is the engineer of record, are they in your office, and did they look at this house before you gave me this number? A firm that handles home addition design and engineering under one roof can answer all three in a sentence. A firm that can’t will tell you it depends.
Ask for the Number
License number in writing, checked on the CSLB lookup. Active status, correct classification, and a name that matches the contract.
Ask Who Engineers It
Get the engineer of record by name, and find out whether they reviewed this house before the number was quoted or will after you sign.
Ask Who Answers the City
Corrections are normal. Find out who writes the response, who resubmits, and whether it’s inside the fee or billed as extra work.
3. What’s Actually Inside the Number?
Four line items account for most of the spread between quotes on the same addition, and all four are easy to leave out of an early number without anyone lying to you.
Structural engineering. Covered above. On a second story or an over-garage build, it isn’t a small line.
Title 24 energy compliance. New conditioned floor area has to be documented, either against the prescriptive requirements for additions or through a performance calculation comparing the altered house to the existing one. It’s a documentation cost rather than a design constraint, but it’s real, and it’s frequently missing from the cheapest bid.
Permit fees and plan check. These are city charges, not contractor margin, and they vary with valuation. A bid that shows them as a placeholder is fine. A bid that leaves them out isn’t.
The zoning check. Floor area ratio, setbacks, lot coverage, and height limits decide how much you can add before anyone prices anything. If nobody on the bidding side has run those numbers, every quote you’re holding may be for an addition that isn’t legal at the size drawn. Our breakdown of how big you can build on an LA lot covers the calculation, and it’s worth doing before the bids come in rather than after.
4. Who Owns the Correction Letter?
Plan check returns corrections. That isn’t a sign anything went wrong. It’s how the process normally works. What matters is what happens next, because the review clock effectively restarts on a complete resubmittal. Whoever responds, and how fast they do it, controls your schedule.
You’ll hear one of two answers. Either the contractor’s team writes the response, resubmits, and carries it through to issuance, or the file comes back to you and you end up coordinating between a drafter, an engineer, and a plan checker who all have different information. The second answer is where addition timelines go to die.
Ask what a correction cycle costs and whether it’s inside the fee. Then ask how many the firm typically takes on an addition this size. A firm with no idea hasn’t tracked it, which tells you something on its own. Our guides to LA permit requirements for room additions and how long a building permit takes in LA lay out what the city expects to see.
5. Are You Comparing Bids, or Comparing Assumptions?
Once the four items above are pinned down, the quotes usually converge, and whatever difference remains is a real one: finish level, schedule, who’s doing the work. That’s a decision you can actually make. Comparing an all-in number against one that leaves out engineering, energy documentation, and permit fees isn’t a decision. It’s a guess dressed up as one.
The cheapest way to make bids comparable is to hand every bidder the same written scope before they price it. If you don’t have one yet, our breakdown of second story addition cost in Los Angeles shows what the line items look like when they’re all present, and you can use it as a checklist against anything you’re sent.
One last note on searching. “Addition contractors near me” returns general contractors, design-build firms, and lead-generation directories in roughly equal measure, and the directories aren’t vetting anyone for the questions above. Five minutes on the CSLB lookup and one question about the engineer of record will tell you more than any ranking will.
Get a Scope Before You Get a Price
We check the zoning envelope and the existing structure first, then give you a scope you can put in front of any bidder. Architecture, structural engineering, and permits in one office, across Los Angeles County.
