- Keep ownership of your data. If estimates aren’t built in your STACK account, you lose long-term visibility and reuse.
- Define scope upfront. Clear responsibilities prevent rework and bid-day surprises.
- Standardize everything. Consistent assemblies and naming make estimates easier to review and scale.
- Collaborate in real time. Working in STACK eliminates version issues and the “black box” effect.
Hiring a third-party estimator can be a smart move when your team’s bandwidth is stretched, demand for bids is high, or you need specialized expertise fast. Industry adoption of third-party estimators is increasing as contractors look for ways to stay competitive without overspending on in-house headcount.
But there’s a catch: if the work happens outside your systems, you risk fragmenting your data, losing visibility into your estimating history, and making future bids harder and slower. The best practice? Require your third-party estimator to use your STACK license so all takeoffs, assemblies, and cost history stay centralized, consistent, and accessible to your business long-term.
Here are the best practices to follow when hiring a third-party estimator so you get speed and scale without sacrificing visibility, consistency, or long-term value.
1. Define the Scope Before You Hire
Before engaging a third-party estimator, it’s critical to define exactly what you’re asking them to do. “Estimating support” can mean very different things, and unclear expectations often lead to rework, delays, and misalignment late in the bidding process.
Start by clearly outlining which tasks the third-party estimator will handle, such as:
- Takeoffs only
- Takeoffs plus pricing
- Fully bid-ready estimates
At the same time, be explicit about what stays in-house. Most contractors retain control over final review, markup strategy, and risk assumptions that are tied to company experience, backlog, or appetite for risk.
When scope isn’t clearly defined, problems tend to surface at the worst possible time, right before bid submission. Internal teams may assume certain items are included when they’re not, or third-party estimators may make pricing assumptions that don’t align with how your business operates.
A clearly defined scope is much easier to manage and enforce when everyone works inside the same estimating platform. When the estimate lives in STACK, responsibilities are visible, progress is transparent, and handoffs are far smoother.
2. Require the Estimator to Work Inside Your STACK Account
One of the biggest mistakes contractors make when outsourcing estimating is allowing the work to happen outside their estimating system. While it may seem faster to accept PDFs or spreadsheets, this approach almost always creates more work in the long run.
Sending estimates back and forth as static files leads to:
- Version control issues when changes are made late in the process
- Lost assemblies, items, and markups that can’t be reused
- No historical data to support future bids
Requiring third-party estimators to work directly inside your STACK account ensures more than just visibility, it ensures STACK-native estimating excellence. Experienced partners leverage real-time collaboration, standardized assemblies, and automated workflows to deliver faster, more confident estimates that align with how your team already works. The benefits are immediate and long-term:
- All takeoffs, items, and assemblies stay in one system
- Estimating standards remain consistent across internal and external teams
- There’s no need to rebuild estimates after delivery
This is a critical mindset shift. You’re not just paying for a one-time takeoff, you’re building an estimating asset. Every third-party estimate completed in STACK strengthens your historical data, speeds up future bids, and improves consistency across projects.
"STACK has doubled my production and increased my accuracy by 500%."
3. Protect Your Estimating Data and Intellectual Property
Estimating data is one of the most valuable assets a contractor owns. Your takeoffs, assemblies, and historical costs reflect years of experience and hard-earned market knowledge. When that data lives in third-party software or disconnected files, you risk losing access and control.
Many contractors have experienced this firsthand. A third-party estimator delivers solid work using their own tools, but once the engagement ends, the contractor is left with static files that can’t be easily reused. The value of the work stops the moment the bid is submitted.
Consistent structure and documented assumptions don’t just make estimates easier to review. They improve accuracy over time, reduce rework, and give teams confidence that each new bid is building on proven data, not starting from scratch.
STACK helps protect your data by keeping everything centralized under your ownership. Project history stays intact regardless of who performed the estimate. Role-based access lets you control exactly what a third-party estimator can view or edit. And when the engagement ends, the transition is clean. No missing files, no data recovery efforts, and no dependence on outside vendors.
4. Standardize Items, Assemblies, and Naming Conventions
Consistency is essential when multiple estimators are involved. Without standardization, estimates can vary in structure, assumptions, and detail, making review difficult and comparisons unreliable.
Using STACK to pre-build core assemblies, establish naming conventions, and align on cost structures creates a shared estimating language. This makes it easier for internal teams to review work performed by third-party estimators and far easier to reuse that work on future projects.
Over time, this standardization reduces estimator dependency. Instead of relying on one person’s memory or methods, your estimating process becomes repeatable, scalable, and easier to train around.
5. Enable Real-Time Collaboration and Visibility
One of the biggest frustrations with using third-party estimators is the “black box” effect — work disappears for days, only to reappear right before bid day with unanswered questions or assumptions that don’t align with reality.
When estimators work in STACK, collaboration happens in real time. Internal teams can see progress as takeoffs are built, review quantities early, and leave comments directly within the project. Questions get answered sooner, assumptions are validated earlier, and surprises are minimized. This is how contractors achieve speed without sacrificing quality. STACK’s real-time visibility allows teams to move faster during peak workload periods while still validating assumptions early and avoiding last-minute surprises.
6. Plan for Review, Revision, and Reuse
Even when outsourcing, your internal team should always have the final say. STACK makes review and revision efficient by allowing teams to validate quantities, adjust assemblies or production rates, and apply company-specific markup strategies without recreating the estimate.
The long-term payoff is reuse. Takeoffs and assemblies completed by third-party estimators become part of your estimating library, helping you bid similar work faster and more consistently in the future.
Working With a Third-Party Doesn’t Mean Giving Up Ownership
Third-party estimators can help you scale bidding capacity and stay competitive without burning out your team. But the real value of estimating lies in the data you retain, not just the bids you submit.
The smartest contractors who hire third-party estimators keep all estimating data centralized in STACK. That way, they gain flexibility without sacrificing control.
When third-party estimators work inside STACK, contractors also gain scalable estimating support — the ability to take on more bids without adding overhead, increasing hiring risk, or losing control of their data.
The final takeaway is simple: If the estimate isn’t in STACK, it’s not truly yours.
STACK Premier Parter
TSARSI is a Premier STACK Partner known for STACK-native estimating excellence. Working directly within STACK’s cloud-based platform, TSARSI helps contractors and building suppliers scale estimating capacity, improve accuracy, and bid faster without sacrificing ownership or consistency. If you’re considering expanding your bidding bandwidth with a partner that truly becomes part of your team, TSARSI is the best option.
