The hardest part of writing an estimate isn't the math — it's the blank page. Knowing you need to price out a deck or a bathroom remodel is easy; knowing where to start the list of labor tasks and materials is where people either spend an hour or skip something important. JobPencil's AI drafting feature solves that specific problem: describe the project in plain language, and a structured first draft appears in seconds with labor tasks, materials pulled from the catalog, and the extras most people forget.
This guide explains how to use it well — because what you put into the description directly determines how useful the draft comes out.
What the AI actually does
When you type a project description and click Draft estimate, JobPencil sends your description to an AI model trained on construction and estimating knowledge, along with the current materials catalog. The model returns a structured breakdown: labor tasks with realistic hours, materials matched to the catalog with current prices, and miscellaneous costs like permits and disposal that belong in the estimate but don't fit neatly into the other categories.
Everything it returns lands as editable line items — the same as if you'd added them manually. The draft is a starting point, not a finished estimate. The AI assumes typical conditions and makes its best guesses about scope; it tells you what those assumptions were so you know exactly where to apply your own judgment.
After the draft appears, the AI review button in the summary panel gives you a second pass: an experienced eye checking whether anything common to this project type is missing, whether hours or quantities look realistic, and whether you've set a contingency margin.
How to write a description that produces a good draft
The description is the only input the AI has to work from. A vague description produces a vague draft; a specific one produces something genuinely useful.
Include the size or scope. The single most important detail. "Build a deck" could mean anything from a 6x8 landing to a 20x30 entertainment platform — the hours and materials are an order of magnitude different. "Build a 12x16 deck" gives the model something to work from.
Name the materials you've already decided on. If you know you want composite decking versus pressure-treated boards, say so. If you've decided on a tile shower surround, name the material. The model will use what you specify and make reasonable default guesses about the rest.
Mention what the project involves beyond the obvious finish work. Demo of an existing structure, electrical or plumbing that needs to move, a sloped site, railing on multiple sides — these all add labor tasks that won't appear in the draft unless you mention them. A deck replacement is a very different estimate from a new deck installation, even at the same size.
Specify the number of workers if it matters. "Two-person crew" versus a solo contractor changes labor hours and rate structure meaningfully.
Examples: weak versus strong descriptions
Weak: "Remodel a bathroom"
This gives the model almost nothing to go on — no size, no scope, no materials, no indication of whether it's a cosmetic refresh or a full gut renovation. The draft will be generic and require significant editing.
Strong: "Full bathroom remodel, approximately 50 sq ft. Demo existing tile tub surround and replace with a 36x60 acrylic shower base and subway tile walls to 72 inches. Replace toilet and vanity in place (no plumbing relocation). New exhaust fan. Paint ceiling and walls. One-person job."
This description will produce a draft with separate labor tasks for demo, waterproofing, tile setting, fixture installation, and painting — materials matched to the catalog for cement board, thinset, grout, and tile — and a misc section with permit and dumpster fees. Still a draft, but a useful one.
Weak: "Paint the house"
Strong: "Exterior paint, two-story colonial, approximately 2,400 sq ft of paintable surface. Includes pressure washing, scraping and spot-priming loose paint, two coats on siding and trim. Two painters."
Weak: "Fence the backyard"
Strong: "Install 160 linear feet of 6-foot pressure-treated privacy fence, replace existing chain link. One double drive gate and one walk gate. Relatively flat terrain."
What to check in the draft before using it
The AI makes assumptions that are reasonable on average but may not match your specific project. Before treating the draft as a real estimate, look at:
Labor hours. The model estimates hours based on typical conditions. If your site has complications — difficult access, unusual materials, a more complex existing structure to demo — adjust the hours accordingly. This is where your experience matters most and the model's is most limited.
Quantities. Check that material quantities make sense for the size you described. The model applies a standard waste factor but doesn't know your specific layout — a room with lots of cuts or a tile pattern that requires careful alignment may need more material than a straightforward run.
Catalog matches. Materials the model matched to your catalog show current prices from the database. Materials it couldn't match are flagged as manual estimates — those prices are the model's best guess, and worth a quick check against current market prices before sending the estimate to a client.
Hourly rate. The draft uses your default hourly rate from your profile. If this job involves different labor categories (your default is a general rate but you have a specialized trade on this job), update the rate on affected lines before finalizing.
What's missing. After looking over the draft, run the AI review in the summary panel — it reads the full estimate and gives you a concise list of what's likely missing or seems off. Common catches: fasteners and hardware omitted from materials, contingency margin not applied, permit fee missing for a project type that typically requires one.
The workflow in practice
The flow that works best for most projects:
- Describe the project specifically (3-5 sentences is plenty, more is fine)
- Click Draft estimate — takes 10-20 seconds
- Read the assumptions note that appears below the button
- Scan the line items and adjust hours, quantities, and any rates that are off
- Add or remove items the model missed or got wrong
- Set your margins and tax rate
- Click AI review in the summary panel and read the feedback
- Address anything it flags, then save and download
The goal isn't to hand off the estimate to the AI and accept what comes back — it's to use a good first draft as the thing you edit rather than starting from a blank page. The time savings come from not having to remember every line item; the judgment still comes from you.
What the AI doesn't know
The model doesn't know your local market, your supplier pricing, your specific crew's productivity, or anything about this particular client or site. It produces estimates based on typical national conditions. Regional price variation on labor especially — the difference between a rural and an urban market can be 40-60% on the same task — is something only you can account for.
It also doesn't have context from your past estimates. For your tenth deck estimate, you know your crew does framing in about two-thirds the hours a national average suggests — the model doesn't. Over time, the right approach is to use AI drafts as your starting point and then apply your own learned adjustments, rather than accepting the hours at face value.
Getting started
You don't need an account to try the builder — but the AI features require signing in, since they're tied to your usage allowance. Create a free account and you get a daily allotment of AI drafts and reviews; premium users get a higher limit.
Start a new estimate and try the draft feature on a real project you're pricing. The best way to get a feel for how specific to be is to try a first description, see what the draft looks like, and refine from there — the model gets meaningfully more useful with each detail you add.