The most common mistake Central Florida homeowners make when soliciting ADU bids is treating it as an informal process. They talk to three builders, each contractor describes what they would do, three very different proposals come back, and the homeowner chooses the cheapest without realizing the three bids are not pricing the same thing. The “$48,000 builder” wins, sixteen weeks later the homeowner is paying $73,000 in change orders to bring the job up to what the $62,000 bid already included, and the entire process was a farce.

The fix is simple but disciplined. You send every bidder the same written package. You require each bid in the same format. You compare on equivalent scope, not totals. This guide walks through how.

What you need before soliciting bids

Five things:

A completed zoning check for your property (see how to check if your lot can accommodate an ADU). You should know the lot area, zoning district, buildable envelope, allowed ADU size, and utility-service plan before you ask anyone to price the work.
A clear program: number of bedrooms, number of bathrooms, approximate square footage, attached/detached/conversion, single story or two, essential features you will not trade away (a full kitchen, in-unit laundry, primary bathroom with a shower vs a tub, etc.).
A finish level target: “builder grade,” “mid-tier,” or “upgraded.” Most homeowners want mid-tier for a rental ADU and upgraded for a unit they or a family member will live in.
A budget ceiling. You do not have to share it with bidders, but you should know it so you can evaluate whether the bids are in realistic territory.
Three to five licensed, insured contractors you have vetted (see how to verify a Florida contractor’s license). Soliciting a bid from an unvetted contractor is wasted time on both sides.

Step 1: Write a bid request package

Every contractor gets the same package. The package contains:

Project description. One page, plain language. The lot, the ADU program (beds/baths/SF/type/stories), the finish level target, and any non-negotiables.

Site information. Parcel ID, legal description, address. A recent boundary survey if you have one — pay for a current survey ($600–$1,800 in Central Florida) before bidding rather than after; it is cheaper than having bidders guess.

Reference plans if you have them. If you have worked with an architect to produce preliminary floor plans, include them. If you do not have plans, include a rough sketch or a floor plan you like from another project as a reference. Many Central Florida ADU specialists offer bid-phase design work (a plan sketch on sketch paper or in SketchUp) that is refined after contract signing. Others expect you to come with plans in hand. Be clear in your request which you expect.

Required bid format. This is the piece most homeowners skip and later regret. Specify that each bid must be itemized by trade, with the following line items at minimum: site work and demolition, foundation, framing, roofing, exterior finish (siding, windows, doors), HVAC, electrical (including subpanel and any service upgrade), plumbing, insulation, drywall, interior finish (flooring, trim, interior doors, paint), cabinetry and counters (as an allowance or selected), appliances (as an allowance or selected), plumbing fixtures (allowance), electrical fixtures and lighting (allowance), landscaping restoration, final site cleanup. Then: permit and impact fees broken out separately (pass-through at cost), general conditions and supervision, contractor overhead and profit.

Also require: a proposed start date and substantial completion date, draw schedule tied to milestones, change-order markup percentage, warranty terms, allowance amounts for each finish category, and attached proof of license and insurance.

Tell each bidder the request is going to three (or four) contractors. This is not a threat. It is a professional courtesy. A builder who refuses to bid competitively has just disqualified themselves.

Deadline. Give bidders two weeks. Two weeks is long enough to do a real takeoff. One week invites sloppy math. Four weeks signals that you are not in a hurry, and some builders will deprioritize you.

Step 2: Send the package and confirm receipt

Email the package as a PDF attachment. Follow up within 48 hours to confirm each contractor received it, is planning to bid, and has no clarifying questions. If a builder says they will bid but then goes quiet, assume they have dropped out. If a builder asks a clarifying question that materially changes the scope (e.g., “do you want me to include the septic work or is that on you”), send the same answer to every bidder so the playing field stays level.

Step 3: Manage the site walk

Every bidder should walk the site once, ideally with you present. Two-hour window, three back-to-back appointments on a single day, is efficient for everyone. Walk the entire lot. Show them where the ADU would go, the proposed utility runs, the driveway and crane access, and anything quirky (a shade tree they would need to work around, an irrigation line, a low area that might need fill). Let them take photos. Answer questions factually and briefly. Do not volunteer your budget.

If a builder wants a second walk before bidding because of something specific they saw, allow it. If a builder wants a second walk because they are not being thorough the first time, take notice — that is how they will run the job.

Step 4: Receive bids and do a scope check before comparing price

When the bids come in, resist the urge to look at the bottom-line totals first. Instead, put the three bids on a table and walk each one through your required line-item list. Are all trades present? Are the allowances reasonable? Are the permit and impact fees included? Does anything look suspiciously low or suspiciously high against your own research?

Two traps to watch for:

The missing allowance trap. Bid A quotes $58,000 total. Bid B quotes $63,000 total. You look at the totals and prefer A. You read the line items: Bid A has a $1,500 appliance allowance (enough for a low-end fridge, range, dishwasher, microwave only if you get lucky); Bid B has a $4,500 appliance allowance (enough for full-size, mid-tier). The $5,000 price gap is not a price gap. It is a $3,000 appliance upgrade you have not priced yet. Adjust Bid A upward by the difference before comparing.

The missing scope trap. Bid C is $12,000 under the other two. You go through the scope: no HVAC. The builder planned to quote HVAC separately as an “add-on” and forgot to mention it. Or: no impact fees. Or: no survey. Or: no site-work line item, because they forgot that your driveway ends where the ADU would be poured and the slab needs an access path. The $12,000 gap evaporates the moment you complete the scope.

Once you have normalized all three bids to equivalent scope with equivalent allowances, the prices should converge within roughly 10–15% of each other. If one bid is still materially low after normalization, that is a signal — most commonly the low bidder has missed something, and will discover it mid-project and bill it as a change order. Occasionally the low bid is real; some builders simply run leaner. Ask the low bidder to walk you through how they priced it. Their answer will tell you whether the number is credible.

Step 5: Compare the non-price factors

Price is one variable. At least as important:

Schedule credibility. Which bidder’s proposed timeline matches what their references reported? A 12-week quote from a builder whose last three ADUs ran 22 weeks is fiction, no matter how good the price.

Change-order markup. A builder with a 25% change-order markup versus one with 15% is a 10-point spread on any scope change. On a $60,000 job where changes typically run 5–15% of contract value, that spread can be $600–$1,800.

Draw schedule. Front-loaded draws (more than 30% before framing is dried in) transfer risk from the builder to you. Back-loaded draws do the opposite. A balanced schedule with a real retainage at the end (3–5%, released 30 days post-CO) is the sign of a builder who is confident in their work.

Warranty terms. Florida’s seven-year statute of repose (Fla. Stat. § 95.11(3)(c), as amended by SB 360 effective April 13, 2023) is the backstop. What the contractor offers above it — typically one year workmanship, two years systems, ten years structural — varies.

Communication. During the bid process, who responded quickly? Who sent a thoughtful clarifying question versus who fired off a rushed quote from the parking lot of another job? The responsiveness you see pre-contract is the upper bound of what you will get once they have your deposit.

Step 6: Negotiate the gap

Once you have picked a preferred bidder, you are allowed to negotiate. Two legitimate negotiation moves:

Alignment to the best competing terms. “Bidder X offered a 5% retainage held 45 days. Would you match that?” Most builders will, because their proposal was a default template and they did not think to tighten terms.

Scope trim. “If we drop the laundry hookup and use a stackable in the primary bath instead, what does that save?” A builder can usually answer this to the dollar during the contract phase; trades are already priced at the trade level.

What you should not do: haggle the bottom-line total. Dropping a competent builder’s price by 10% with no scope reduction is not a win. It means they will find 10% elsewhere — usually in the allowances that show up on your selections list sixty days later.

Step 7: Read the contract before signing

The bid becomes a contract. Before signing, verify:

The contracting entity on the signature line matches the entity that holds the Florida contractor license.
The total contract price, draw schedule, allowances, scope, calendar, and change-order procedure in the contract match the accepted bid.
The contract does not waive your right to Florida Homeowners’ Construction Recovery Fund claims, does not require out-of-state arbitration, does not waive your right to receive a Contractor’s Final Affidavit before final payment, and does not include any clause that ships your notice rights to a PO box you will never check.
Lien-waiver mechanics are spelled out: partial lien waivers from every sub at every draw, final unconditional waivers before final payment.
The deposit is 10% or less.
The contract is signed by the license qualifier or a corporate officer of the qualified business, not by a salesperson with no signing authority.

If any of this is not right, mark it up, send it back, and wait for a revised draft. A builder who refuses to clean up the contract is a builder you do not want to sign with.

What happens after you sign

Once the contract is signed, file it. Make a folder — digital is fine — with the contract, license copy, insurance certificate, workers’ comp verification, final plans, survey, and every email exchanged with the builder during bidding. As the project runs, add draw invoices, inspector reports, change orders (signed), lien waivers, and the certificate of occupancy. If something goes wrong eighteen months later, this folder is your file.

This guide gets you from “I’m thinking about an ADU” to a signed contract with a credible builder. What happens next — construction, inspections, final walkthrough, CO, and the first year of operation if you rent the unit — is a different set of guides we will publish as they are ready. Start here and the rest is easier.

For context on why these steps matter, see the builders overview, the costs pillar, and the financing pillar.

Last reviewed: April 17, 2026. This guide is informational. Consult a Florida-licensed attorney before signing any construction contract.