Pilars vs STACK.
STACK is a cloud takeoff and estimating platform with one of the largest user bases in the business. Pilars is an automated takeoff that hands you quantities. They overlap on one step of the bid and differ on almost everything around it, so the right pick depends on which step is costing you the most time.
Pilars vs STACK: what is the difference?
STACK is browser-based on-screen takeoff plus estimating and proposals, priced per user from "as low as $299 per user per month" for Takeoff and Estimate, with a free version and optional AI assist features. Pilars is fully automated AI takeoff priced at $300 per user per month, with one trade per user, unlimited takeoffs and monthly billing available. The listed seat prices are close, and STACK's includes estimating. STACK is the better pick when you need takeoff, estimate and proposal in one seat; Pilars is the better pick when the takeoff itself is the bottleneck and you want it done before you open the file.
Put simply, STACK gives the estimator a very good place to work. Pilars tries to remove a block of the work. Both are legitimate ways to bid faster, and a fair number of shops will end up wanting some of each.
| Pilars | STACK | |
|---|---|---|
| What it is | Fully automated AI takeoff with code-compliance flags | Cloud on-screen takeoff plus estimating and proposals, with AI assist features |
| Who reads the drawings | The software reads the set and spec book; the estimator reviews and can change any detection | The estimator measures and counts; STACK Assist automates some counts, walls and areas |
| Platform | Browser | Browser |
| Pricing model | Per user; each user includes one trade, with unlimited takeoffs. Monthly or annual billing | Per user subscription; AI floor plan features are an add-on |
| Public price | $300 per user per month ($3,600 per user per year) | Takeoff and Estimate "as low as $299 per user / month"; full platform "as low as $348 per user / month"; free version available |
| Estimate and proposal | Not included. Exports a takeoff summary and BOQ or Excel file | Included |
| Best for | Subs who want the first pass done for them and already have a way to price it | Subs and GCs who want one cloud seat from takeoff through proposal |
Pricing reviewed 13 November 2026, based on public documentation as of Nov 2026. STACK publishes "as low as" figures and does not state the billing term on its pricing page, so ask for a written quote. STACK is a trademark of its owner; this is an independent comparison written by Pilars.
What STACK does that Pilars does not
Start with the obvious one. STACK takes a bid from drawings to a priced proposal inside a single product. You measure on screen, the quantities feed an estimate, and the estimate becomes a proposal you can send. Pilars ends at quantities: a takeoff summary and a BOQ or Excel export that you price in whatever estimate you already use. If the gap in your shop is that pricing lives in six different spreadsheets, STACK addresses that and Pilars does not.
Second, STACK has a free version of Takeoff and Estimate. Pilars has no free tier; you can have the demo run on your own plan set, but ongoing use is $300 per user per month. For a one-person shop bidding a handful of small jobs, free manual takeoff is a hard price to argue with.
Third, STACK has a second product line, Build and Operate, listed from "as low as $49 per user / month", for the field side of the job. Pilars is a preconstruction tool only.
Fourth, STACK IQ. STACK describes it as a connector that lets assistants such as Claude, ChatGPT and Copilot operate STACK, and says it is included in all paid subscriptions at no extra charge. If your team is already working inside one of those assistants, that is a real convenience.
And STACK is a known quantity. It has a large, mature review base and a long list of contractors who learned takeoff on it. Hiring an estimator who already knows STACK is not difficult.
How the AI differs
STACK's AI sits beside the manual tools. STACK Assist automates counts for doors, windows and symbols, interior and exterior wall takeoffs, and gross and room areas. Two details from STACK's own help documentation are worth knowing before you budget. Floor Plan AI is described as an add-on to your STACK subscription, with the price coming from your account manager rather than the pricing page. Symbol Counting AI is documented as currently available only on electrical plan sheets.
Pilars is built the other way around. There is no manual first pass to assist. You upload the PDF set, and the software reads every sheet and the spec book together, resolves cross-sheet references and the door, window, fixture and equipment schedules, counts and measures across 19 trades, traces runs, and flags code-compliance issues against IBC, NEC, IPC, IMC, ADA and NFPA. Each quantity is confidence-scored and tied back to the sheet it came from. The first pass takes minutes, not a day of clicking.
That does not make it a sealed box. An estimator used to STACK's hands-on tools will want to know they can still get at the takeoff, and they can: open any detection, reclassify it, add or delete an item, move a boundary or change the quantity, and the totals recalculate. Pilars does the first pass; the estimator decides what the bid says.
For a sense of how the two compare on one narrow task, Pilars published a test on a real power plan: its fine-tuned model counted duplex receptacles at 97.5% and STACK scored 72% in the same test. One sheet, one device type, and Pilars ran it, so read the benchmark method and try the same exercise on your own set.
Cost for a three-estimator shop
STACK does not publish an annual total, so this is an illustration built on its "as low as" rate, not a quote. If three estimators each held a Takeoff and Estimate seat at $299 per month for twelve months, that would be $10,764 a year before any Floor Plan AI add-on. Your actual quote may differ.
The same shop on Pilars is three users at $900 a month, or $10,800 over a year, with unlimited takeoffs in each user's trade. On those figures the two bills are $36 apart. The count changes if each estimator takes off two trades: a Pilars user covers one, so that shop needs six users at $21,600 a year, and STACK's seats are clearly cheaper, with estimating included.
Three honest caveats. STACK's price buys an estimating and proposal system as well as takeoff, so you are not comparing like for like. STACK's free version costs nothing at all, which no paid seat can match. And on either product the software line is small next to labour: a manual commercial takeoff commonly runs 40 to 80 hours, and that is the cost Pilars is aimed at. The takeoff ROI calculator lets you put your own hourly rate against it.
Best for: the verdict on each
STACK is best for
- Contractors who want takeoff, estimate and proposal in one cloud seat
- Small shops that can start on the free version and grow into a paid plan
- Teams that want preconstruction and field tools from one vendor
- Estimators who prefer to measure themselves and use AI as a helper
- Companies that value a mature product with a large user community
Pilars is best for
- Subcontractors whose bid volume is capped by takeoff hours
- MEP and fire protection trades, where counts, runs and schedules dominate
- Firms that already have an estimating system and only need quantities
- Estimators who bid one trade at volume and want unlimited takeoffs at a flat monthly price
- Shops that want a published price and the option of monthly billing
There is a sensible combined setup as well: run the set through Pilars for the quantities, then price and propose in the estimating tool you already own, STACK included. If you are replacing STACK outright, see the STACK alternative page.
Questions to ask before you sign either one
- Ask STACK for the billing term and the total for your seat count in writing, and ask what Floor Plan AI adds per user.
- Ask whether the AI features you care about work on your sheets. Symbol counting on plumbing or mechanical plans is a different question from symbol counting on electrical plans.
- List which trades each estimator takes off. Every estimator-and-trade pair is one Pilars user at $300 a month, and that count is your Pilars cost.
- Run one finished job through both. Use STACK's free version or a trial and the Pilars demo on the same PDF, and compare against the quantities you bid.
Questions estimators actually ask
Is Pilars better than STACK?
Pilars is better when takeoff hours are the constraint, because Pilars reads the plan set and spec book automatically and returns quantities to review. STACK is better when you need takeoff, estimating and proposals in one product, or when you want to start on a free version.
How much does STACK cost compared with Pilars?
STACK lists Takeoff and Estimate at as low as $299 per user per month and also offers a free version. Pilars costs $300 per user per month, with one trade per user and unlimited takeoffs, so the paid seats are priced about the same and STACK's includes estimating.
Does STACK have AI takeoff like Pilars?
STACK has AI assist features: STACK Assist automates counts for doors, windows and symbols plus wall and area takeoffs, and Floor Plan AI is a paid add-on. Pilars is fully automated, reading the whole set and spec book and returning quantities without a manual first pass.
Which is cheaper for a three-estimator shop, Pilars or STACK?
Three STACK seats at the listed as-low-as rate of $299 per month would total about $10,764 over twelve months, before AI add-ons. Three Pilars users cost $900 a month, or $10,800 a year, so neither is meaningfully cheaper; STACK's seat includes estimating and proposals, and each Pilars user covers one trade with unlimited takeoffs.
Is there a free version of STACK or Pilars?
STACK offers a free version of Takeoff and Estimate. Pilars does not have a free tier, but you can run the Pilars demo on your own plan set before paying.
Can I use Pilars for takeoff and still estimate in STACK?
Yes, in the sense that Pilars exports a takeoff summary and a BOQ or Excel file that you can price in any estimating system. Check with STACK how you would bring outside quantities into a STACK estimate.
Does STACK symbol counting work for plumbing and HVAC plans?
STACK's help documentation describes Symbol Counting AI as currently available only on electrical plan sheets. Pilars covers plumbing, HVAC and fire protection among its 19 trades.