Bildrix vs STACK | The Ultimate Comparison Guide

If you have shopped for takeoff software, you have seen STACK. Around since 2011 (it started as CloudTakeoff), it runs in the browser, and its pitch has stayed consistent: measure in the cloud, price in the same platform, hand the numbers to Excel, QuickBooks or your ERP. More recently STACK has layered AI on top: Floor Plan AI for doors, windows, rooms and walls, Autocount for symbols, STACK Assist for questions about the plans.

Bildrix was built for a different shop and a different job. Our customer is the owner-estimator at a 1 to 15 person electrical sub or small GC, bidding commercial and TI work from PDF plan sets in the US and Canada. They want an AI first pass they can review instead of redo, device counts that match the legend, wire runs they can edit, and a way to turn all of that into a priced estimate, a signed change order and an invoice without retyping a number. And one price for the shop, not per seat plus an add-on for the AI.

We could just tell you Bildrix is the better choice for that shop and leave it there. Instead we compared the two properly: the takeoff itself, electrical depth, what happens after the takeoff, revisions, getting started, and price. One ground rule. Everything we say about STACK comes from STACK's own website and help center, read on August 19, 2026, and we link the page each time. Where STACK's pages are silent, we say "not described" rather than guessing.

TL;DR: Bildrix vs STACK

Bildrix vs STACK at a glance

Both products start the same way: upload a plan set, get counts and measurements, price them, export. Both run in the browser, both let you correct what a tool produced, and both publish a price. The differences start when you ask where the AI sits, who the product was built for, and where the numbers end up.

STACK

• A cloud takeoff and estimating platform since 2011, with trade pages from concrete to site work
• Nine manual measurement types, Autocount, OCR text search, auto-naming
• Floor Plan AI, a paid add-on that detects doors, windows, rooms and walls one sheet at a time
• A deep estimate worksheet: assemblies, four cost types, labor hours, snapshots, a paid Excel add-in
• Takes PDF, ZIP, PNG, JPG and TIFF; unlimited viewer seats, roles, an audit trail
• Priced per full-access user on 12-month terms; 7-day free account

Bildrix

• Built for electrical subs and small GCs in the US and Canada who bid from PDF plan sets
• Runs an AI first pass across the set and counts electrical devices against the sheet's own legend
• Draws wire runs with a live footage readout, or suggests them run by run to accept, reject or reshape
• Groups circuits, devices and wire on separate ledgers
• Puts a confidence level on every detection and flags the uncertain ones for review
• Carries the same quantities into the estimate, signed proposal, AIA G701 format change order and invoice
• Turns a plan revision into a priced change order, reductions included as credits
• One flat published price for the whole workspace, up to 5 teammates included
• Free trial of 15 AI detection pages, no credit card, plus a free first takeoff
• Covers architectural and electrical in depth, plumbing fixture counts on demand, and says what it does not cover yet

Quick verdict

If you only read one table, read this one.

Feature comparison

A mature interface gets you through the demo. Features get you through bid week. So this is where we go category by category: the takeoff experience, electrical depth, what happens after the takeoff, revisions, and how you get started. In each category we show what each product does, in a table, and call a winner. STACK has spent more than a decade building a takeoff and estimating platform, and credit where it is due. But STACK added AI to a manual workflow for estimating teams, and Bildrix was built around the AI pass to get a small electrical shop from a plan set to a signed bid. Those are different jobs, and it shows. Every STACK statement links to the page it came from.

Takeoff experience

The first thing a takeoff tool has to do is read the plan set and give you something better than a blank sheet. STACK's manual layer is mature: nine measurement types, templates, labels, OCR search. Its AI layer sits on top. Floor Plan AI, an add-on, detects doors, windows, rooms and walls; its help center says you run it one sheet at a time, results "are meant to be a starting point", and you are "responsible for reviewing everything". Autocount finds copies of a symbol you box.

Bildrix starts with the AI pass. Upload a PDF plan set, let Detect All run trade by trade, then get the part most tools skip. Every detection carries a confidence level. Uncertain detections are flagged and queued for review, so you verify the flagged minority instead of rechecking the sheet. Every count, boundary and wire route is editable on the drawing; what the AI misses you count or draw in the same takeoff. The complete guide walks through the first pass.

Bildrix flags the detections it is not sure about, so you review the flagged minority instead of the whole sheet.

Winner: Bildrix

STACK's manual tools are as complete as any. We call this one for Bildrix because of what the AI hands back. A first pass you recheck in full has saved you very little. A first pass across the set that tells you which twenty detections to look at has saved you the evening. That is the difference between an AI that helps you estimate and one that makes you audit.

Electrical takeoff

This is the category Bildrix was built around, so we will be specific. An electrical estimator needs three things from a takeoff: device counts that match the legend, wire footage per run, and circuits grouped so the estimate can price them. A room count does not bid a TI fit-out.

STACK's electrical page is honest about what it offers: Autocount "quickly counts most plan symbols", and "with just a few clicks" you measure the wire you need. A Linear with Drop type adds drops to a wire run, the help center lists a Division 26 quick-start assembly, and an experimental Symbol Counting AI for electrical sheets lives in Labs, one sheet at a time. Useful, and still hand measurement with assists. Nothing describes legend matching, AI-suggested runs or circuits.

Bildrix reads the electrical sheets like an estimator. It finds the legend first and counts devices against it, so a GFCI is a GFCI, not a generic symbol. You draw wire runs that snap to devices with a live footage readout, or let the AI suggest switch legs, receptacle chains and homeruns and review each: accept, reject, or drag the route. Circuits are grouped, devices and wire land on separate ledgers, and a built-in catalog prices the counts. It all flows into a division-26 estimate; the electrical page shows each step.

Wire runs in Bildrix snap to devices, with footage updating as you draw. AI-suggested runs are reviewed one at a time.

Winner: Bildrix

This one is clear, and it is no knock on STACK. Its electrical page is a trade view of a general takeoff tool: count symbols, measure wire, build assemblies. Bildrix's electrical takeoff is the product. If your bids are devices, wire and circuits, the gap shows on the first sheet, and again when the counts drop into a priced division-26 estimate with no spreadsheet in between. If your work is roofing or concrete, STACK's breadth serves you better; see its advantages below.

From takeoff to estimate, change order and invoice

A takeoff is not the job. The job is a bid the client signs, a change order when the drawings move, and an invoice that gets paid. STACK goes further than most, so let us be precise about where its thread ends.

STACK's estimating is the deepest part of the product. On Pro, the Estimate Worksheet holds assemblies, four cost types, markups, labor hours and snapshots, and exports to CSV, XLS, an Excel proposal with a signature line, QuickBooks Online or an ERP. Not described: a client e-signature, a change order document, an invoice.

Bildrix keeps going. The takeoff becomes a priced estimate with provenance on every line: your price book, an AI price, or an AI quantity. The client signs on a share page sealed with a SHA-256 fingerprint and bound to the plan revision. Payment schedules, deposit and progress invoices, retainage, online payment and QuickBooks-ready CSVs close the loop.

Every line in a Bildrix estimate shows where its number came from: your price book, an AI price, or an AI quantity.

Winner: Bildrix

On estimating depth alone STACK wins. We call the category for Bildrix because of where each thread ends. With STACK you price in a worksheet, then switch tools to get signed, changed and paid. With Bildrix the quantities keep their identity to the invoice, so a device counted on sheet E-201 is the device the client signed for and the one you billed.

Revisions and plan comparison

Drawings change. An addendum lands two days before the bid, a bulletin lands after award, and the cost of a missed wall is yours. Both products compare drawing sets, so let us be precise about what each gives you afterwards.

STACK's takeoff page lists Plan Overlay to "instantly identify changes between document versions"; the help center's Overlay layers sheets in different colors, and estimate snapshots keep the version you quoted. Both are useful.

Bildrix treats the revision as the start of a document. Upload the revised set and the sheets pair by drawing number. Compare Pages overlays any two sheets. Then the diff is staged as a change order in AIA G701 format, added scope priced from your estimate and reductions booked as credits, ready for the client to sign against the revision it references. It is sealed like the original proposal, so nobody argues later about which drawing it was based on.

The revision diff becomes a priced change order in AIA G701 format, with reductions booked as credits.

Winner: Bildrix

Comparison is table stakes now, and STACK does it well. Bildrix wins because of the last step. A list of changed quantities is information. A signed change order is money. For a small sub that gap is a week of chasing. Staging the change order straight from the diff, credits already on it, does not demo as well as a colored overlay and saves you more.

Getting started: trial, sign-up and support

Both let you start without a sales call; the details tell you who each was built for.

STACK's pricing page offers a free account with "Pro-level features on any project for 7 days"; its FAQ adds the limits: two projects, ten takeoffs per project, no Autocount, cost data, API or export. Floor Plan AI is an add-on; the help center says to contact your account manager for pricing. A June 2026 trial we ran matched that.

Bildrix assumes you would rather try the AI than read about it. Start free in the app with no credit card and run detection on 15 pages of your own plan set; viewing, measuring by hand and exporting never count against the cap. Or book a call and we will run your first takeoff free and walk you through it. Live chat is staffed Monday to Friday. The price is on the pricing page. Nobody has to qualify you first.

Winner: Bildrix

STACK's free account is real and its onboarding is thorough, so take this verdict for what it is: a verdict about trying the AI before you pay. A small shop bidding on Thursday wants to upload a set tonight and see what the AI flags on its own drawings, not learn that the detection it came for is a priced add-on. Bildrix puts the AI pass in the trial and the price on the page.

Pricing comparison

Both publish prices. STACK prices per full-access user on 12-month terms; Bildrix prices the workspace, billed annually. As of August 19, 2026, from STACK's pricing page and ours:

The math for a small team is not close. Two STACK Pro seats cost more per year than a full Bildrix workspace at list price, before the AI add-on. At the founding rate, five people on Bildrix cost about one tenth of five STACK Pro seats. Prices and terms change, so check both pages.

STACK advantages

We said at the top that STACK is the established platform in this category for good reasons. Here they are, stated as plainly as the verdicts above. A comparison that cannot name the other side's strengths is not worth reading.

• Estimating depth: the Estimate Worksheet on Pro is a serious estimating engine: assemblies with formula variables, four cost types, labor hours, markups, regional cost data, dashboards, snapshots, and an AI prompt that flags lines with missing quantities or unit costs. STACK for Excel streams live data into your own workbook. Bildrix prices from your price book or the AI and stops well short of that.
• Collaboration and enterprise trim: unlimited viewer seats, eight roles with permissions, Share and Invite links for outsiders, an audit trail, SOC 2, an API, and integrations with Procore, Dodge, QuickBooks, Sage Intacct, Acumatica and NetSuite. Bildrix is a workspace for up to 5 teammates with a client share page.
• Breadth: trade pages from concrete to site work, PDF, ZIP, PNG, JPG and TIFF input, aerial imagery, metric and imperial units, and pricing in US or Canadian dollars. Bildrix covers architectural and electrical in depth, plumbing fixture counts on demand, PDF only, and nothing else yet.
• Maturity and support: founded in 2011, "thousands of contractors" on the homepage, an account manager and onboarding specialist, 1:1 training in English, Spanish and French, and fee-based Professional Services where former estimators build your assemblies library. Bildrix is newer and says so.

Bildrix advantages

Bildrix was designed around the AI pass and the part of the job after the counting, for the shop where the owner is also the estimator. None of these is a feature for the demo. They are for the night before a bid is due.

• Review-first AI that shows its doubt: every detection carries a confidence level and the uncertain ones are flagged for review, so you verify the flagged minority instead of recounting the sheet. We do not publish an accuracy percentage, and we wrote a research page on why no vendor's number should be taken at face value. STACK's help center says its AI results are a starting point you review in full; it describes no flag to tell you where.
• Electrical depth built for subs: devices counted from the legend, wire runs drawn or AI-suggested and edited run by run, circuits grouped, devices and wire on separate ledgers, a built-in price catalog, and a division-26 estimate at the end. STACK's electrical pages describe Autocount, hand-measured wire and a quick-start conduit assembly.
• One thread from plan set to invoice: a priced estimate with per-line provenance, client e-sign sealed to the revision, change orders in AIA G701 format with credits, invoices with online payment, and QuickBooks-ready CSVs. The quantities never leave the system, so they never get retyped wrong. The product page lays the thread out trade by trade.
• A flat price, AI included, and a trial you can start: one workspace price on the pricing page, 5 teammates included, a founding rate for the first 100 customers, 15 free AI detection pages with no card, and a free first takeoff with a review call. STACK charges per user and prices Floor Plan AI as an add-on.

Which platform should you choose?

It comes down to what you bid, who bids it with you, and whether you want the AI to lead or assist:

Choose STACK if you…

• Run a multi-trade precon team on one mature platform
• Want a deep worksheet with formula assemblies, labor hours and an Excel add-in
• Need roles, an audit trail, SOC 2, an API or ERP connectors
• Upload images or aerials as often as PDFs

Choose Bildrix if you…

• Are an electrical sub or small GC in the US or Canada
• Want an AI first pass that flags what to double-check
• Need device counts, wire runs and circuits, not just rooms
• Want the takeoff to become the estimate, change order and invoice
• Want to try the AI today, price already on the page
• Want one flat workspace price, not per-seat plus an add-on

Pick the one that matches your Tuesday.

Conclusion

Both are real tools, honest about what they are. STACK is the mature cloud platform for estimating teams, with AI as assists and add-ons. Bildrix takes a small electrical shop from plan set to signed, invoiced job, AI pass in front, and tells you where to look.

For the shops this guide is written for, Bildrix comes out ahead where a bid is decided: the AI pass and its review queue, electrical depth, the thread to invoice, revisions, price. STACK keeps the edge on estimating depth, collaboration, breadth and enterprise trim.

If that sounds like your shop, try it on your own plans. Start free in the app, no credit card, 15 AI detection pages. Or book a free first takeoff review.

Frequently asked questions

1. Is Bildrix better than STACK?

   For a 1 to 15 person electrical sub or small GC bidding plan-set work in the US or Canada, yes. Bildrix runs an AI first pass and flags what to double-check, goes deeper on electrical, carries quantities through to the invoice, and costs less for any team of two or more. A precon team wanting a mature manual platform may prefer STACK.

2. What is the biggest difference between Bildrix and STACK?

   Where the AI sits and where the thread ends. In STACK the AI is a layer on a manual takeoff: Floor Plan AI is a paid add-on and no confidence flag is described. In Bildrix the AI pass is the product, every detection carries a confidence level, and the quantities become a signed proposal, change order and invoices.

3. Which is better for electrical contractors?

   Bildrix, for a small shop. It counts devices against the legend, suggests wire runs you accept, reject or reshape, groups circuits and lands everything in a division-26 estimate. STACK measures wire by hand, counts symbols with Autocount from an example you box, and offers an experimental symbol counter in Labs.

4. Which is better for general contractors?

   It depends on the GC. A small GC running plan-set jobs gets one consistent set of base quantities plus the estimate, change order and invoice thread from Bildrix. A GC with a precon department, many trades and an ERP to feed will get more from STACK's worksheet, roles and connectors.

5. Does Bildrix offer a free trial?

   Yes. Start in the app with no credit card and run AI detection on 15 pages of your own set; viewing, measuring by hand and exporting never count against the cap. Or book a call for a free first takeoff. STACK's free account lasts 7 days on two projects without exports or Autocount; Floor Plan AI is an add-on priced through an account manager.

6. Which is more affordable?

   Bildrix, for any team of two or more. As of August 19, 2026, STACK Pro is $299 per user per month billed annually, so five seats are $17,940 a year before the Floor Plan AI add-on. Bildrix Pro is $397 per month billed annually, $4,764 a year for the whole workspace with up to 5 teammates, and the founding rate for the first 100 customers is $149 per month. Prices change; check both pages.

7. Does Bildrix handle estimates, change orders and invoices?

   Yes. Estimates carry per-line provenance, the client signs on a share page sealed to the plan revision, change orders are staged in AIA G701 format with credits, and invoices cover deposit, progress, final and retainage with QuickBooks-ready CSVs. STACK exports its worksheet to Excel, QuickBooks or an ERP and describes no e-sign, change order document or invoicing.

8. Can I switch from STACK to Bildrix?

   Yes, without exporting anything from STACK first. Bildrix works from the PDF plan set: upload it, let Detect All run, and compare with the takeoff you already have. Bring a set you took off in STACK to the free first takeoff review and compare counts, flags and time to a priced estimate.