Case study: A specialty mechanical and plumbing contractor's job costing transformation on Sage Intacct Construction

Interstate Mechanical & Core’s project managers worked in Procore. Accounting worked in Sage 300. Every job-cost question had to cross that split: the field logged work in one system while finance costed it in another, and the mechanical, HVAC, and plumbing contractor had outgrown the older system holding its books. Moving to cloud accounting that worked with Procore meant redesigning job costing so the numbers finally reflected what the field was already doing.

Interstate is a useful blueprint for a contractor already running structured Sage accounting alongside Procore. A QuickBooks-first or inventory-heavy shop faces a different lift, where dimensions, item history, and cleanup drive the work.

We implement and support construction accounting systems for a living. In projects like this, the work that decides success happens before daily transactions start: jobs, cost codes, account segments, and Procore ownership have to be organized before job cost becomes the report everyone trusts.

For this case, we sat down with Tina Rehberg, our Senior Sage Intacct Consultant and the main implementation voice here. Tina spent over 30 years in construction finance, controller to CFO, before consulting, and she first worked on Interstate at Digitech Solutions, the construction-focused Sage firm that later merged into Alta Vista Technology. We also asked Troy Guevara, our Construction Technologist, and Audra Speth, our Customer Success Manager, where moves like this get harder than expected. One naming note: Tina described Interstate’s legacy system as Sage 300. If your current system is Sage 300 CRE, confirm the distinction before scoping, because the Sage product names are easy to confuse.

Why the pressure started in operations

Tina’s line shows why the move belonged in operations as much as finance. Sage 300 had given Interstate a structured accounting base and Procore had become part of the project environment. The company needed a cloud accounting foundation that could support job-costing structure and fit the project information its managers were already using.

A reliable legacy system can still fall behind the way a contractor now runs jobs, reports costs, and shares project information. That is the point many contractors reach before they replace an older accounting environment. The old system may still close the books while job-costing structure, project workflows, and reporting needs drift apart.

Troy told us one of the first buyer mistakes is assuming Sage product names are interchangeable. His warning was simple: “You have to be specific about which Sage product you’re talking about.” Sage 300, Sage 300 CRE, standard Sage Intacct, and Sage Intacct Construction are different conversations. Sage Intacct Construction is the construction edition contractors should be evaluating when job costing, cost codes, project profit and loss, and construction workflows are in scope.

What Interstate had before the move

Interstate already had a structured Sage accounting foundation and Procore in the project environment. The implementation team had to respect both sides: the account structure already in use and the project steps managers used in daily work.

Tina has seen this play out differently in another plumbing implementation — Interstate's looser, more general cost-code structure was different from an implementation with strict item IDs and part numbers already built in. It was also a different lift from a QuickBooks migration, where contractors often need more education around projects, cost codes, and dimensions.

That shaped the work. The project centered on translating Sage 300 account logic and cost-code activity into Sage Intacct Construction’s dimension model, where transactions are tagged by the reporting details the contractor needs.

How Sage 300 became a dimensions conversation

Sage 300 users often have a useful head start because they already understand segmented accounting. Tina described the pattern this way: “A Sage 300 client is already in the mindset and structure we need for Intacct. They use a GL structure with a prefix, a base account, and sub-accounts.”

That gives the team familiar pieces to map. The prefix may point to a company or entity. Base accounts cover revenue, labor, materials, and overhead. Subaccounts can become dimensions: the transaction tags that let job activity be reported by job, cost code, and cost type without spawning a separate account for every combination.

The software term is usually easier than the business decision behind it. Tina’s shortest answer on the biggest conceptual hurdle was: “Dimensions, by far.”

The difficulty is deciding what each old segment actually means. If a Sage 300 subaccount was really being used as a location, it may become a location dimension. If a subaccount was being used as a cost category, copying it forward as-is will only prolong confusion. The lesson: while old codes usually meant something once, the job is figuring out which of those reasons still hold before they harden into permanent reporting structure.

Tina told us she lets the client describe its own world first, then adapts the Sage Intacct language to the team’s vocabulary. A Sage 300 user might talk in prefixes and subaccounts, while a project team might talk in tasks, phases, or cost codes. The implementation has to connect those words to the way accounting will code transactions after go-live.

Why Sterling mattered

A migration is only as clean as the person on the client side who can still read the old structure. Tina described Interstate as having “very smart people,” and she specifically said their key person, Sterling, “made it easy to bring the data over cleanly.”

The key here is that Interstate had someone on the client side who could interpret the old structure and validate what came forward.

A consultant can extract records, map fields, and help test balances. The contractor still has to answer the business questions behind the data:

• Which old codes still mean something?
• Which jobs and cost codes should remain active?
• Which historical data is useful enough to bring forward?
• Which values would confuse users if they became dimensions?
• Which job-cost reports should be used to check whether the new setup makes sense?

If the structure is wrong, the first problems are practical. Reports do not reconcile the way people expect. Project managers stop trusting job cost. Accounting starts cleaning up codes manually. The spreadsheet that everyone wanted to retire comes back.

Troy doesn't dress it up. Asked what goes wrong most often, he said: “Trying to keep their old ways.” Sage Intacct Construction can carry a cleaner structure, but the contractor has to decide which old habits should stay behind.

How Procore shaped the setup

Procore was part of the reason the Interstate move had to be designed carefully. Tina identified Procore compatibility as a real requirement because project managers were part of the operating picture.

For a contractor like Interstate, Procore scoping should happen before accounting configuration is locked. The useful questions are about ownership:

• Who creates the job or project record? If accounting and Procore use different project IDs, job-cost reporting can break before the first invoice is posted.
• Who maintains cost codes and cost types? If project teams and accounting edit codes separately, stale or duplicate values can appear in transactions.
• Where do project cost approvals happen? The accounting team needs to know what approval means before a cost is posted to a job.
• What project information do PMs rely on in Procore? The setup should account for the job, budget, cost, and approval information project managers expect to see.
• Who fixes mismatches? Someone needs responsibility for resolving differences between accounting data and Procore data before users build workarounds.

Troy tells construction buyers to ask implementation partners practical questions early: “What does data migration look like? Can we connect third-party platforms? What do we need to change to make this system work for us?” For a Sage 300 and Procore contractor, those are design questions to settle before the software choice is final.

What changed after go-live

One honest caveat: we don't have numbers that show Interstate's time savings or margin lift. What the case does show is how the structure was rebuilt so job cost could be trusted. After go-live, the meaningful change was in job-cost trust: in the dimension structure and  daily coding discipline behind it. Vendor invoices had to hit the right job and cost code, labor had to land in the right category, cost-code changes needed an owner, and the controller’s job-cost report had to be checked against the way Interstate actually managed work.

Sage Intacct Construction shifted more reporting work into dimensions so project costs could be coded by job, cost code, cost type, and other chosen views. That gives accounting a cleaner foundation for job-cost reporting when users enter transaction detail consistently.

Troy makes the management boundary clear in broader construction implementations: “Software can’t fix a management problem. If leadership tolerates a bad process, the software isn’t going to enforce what leadership won’t.”

Audra, who works with our Sage Intacct customers after go-live, described durable rollouts as “a structured, deliberate attempt with constant check-ins, never a blitz.” For job costing, those check-ins are where the team catches stale codes, reports the team doesn't trust, and Procore mismatches before people rebuild spreadsheets.

What similar contractors should take from Interstate

Interstate’s story is strongest for contractors with three ingredients: structured Sage accounting, a capable client-side data owner, and Procore already in the project environment.

Use Interstate as a blueprint if your team can explain how your current codes work, decide what should change, and validate the new dimension structure before daily use. Treat it as a different project if you are moving from QuickBooks, carrying strict item-level inventory, or trying to redesign service operations at the same time.

The buyer judgment is simple. If your current pain is delayed or mistrusted job cost, Sage Intacct Construction is worth evaluating. If your main pain is field service dispatch, warehouse inventory, or project management adoption, solve that scope first or include it explicitly so the accounting implementation does not inherit a problem nobody owns.