HVAC is service in the slow seasons, replacement during peak, and commercial install on the GC schedule. Most HVAC software optimizes for one of those — typically service dispatch — and forces commercial work into a square hole. BuildCrux ships AI estimating that reads commercial mechanical drawing sets in twelve minutes alongside mobile-first service-call workflows that close on the truck.
BuildCrux is contractor management software with AI estimating verified inside expert reference ranges on commercial work. HVAC contractors use it for equipment-and-load takeoff on commercial bids, replacement quoting, service-call invoicing, and per-truck profitability reporting.
The three HVAC workflows
Service-call dispatch in shoulder seasons
October and April are maintenance months. Techs run 8 to 12 calls a day, each needing a quote, customer signature, work log, and invoice. Office-only software forces double-entry; mobile-first software closes the call on the truck.
Replacement quoting in peak season
July condenser dies, August heat exchanger cracks. Replacement quotes have to go out same-day with equipment options, financing options, and warranty information. Customers are frustrated and want answers fast. A clean quote from the driveway with a Stripe-linked deposit closes more sales than a printed quote mailed two days later.
Commercial install on the GC schedule
Commercial mechanical bids count tonnage, identify zoned controls, calculate make-up air loads, price refrigeration line sets, and apply commercial uplift on labor. Manual takeoff on a 50-sheet mechanical-and-plumbing set is 10 to 16 hours. AI takeoff cuts that to 12 minutes.
Per-truck profitability is invisible
You know the company is profitable in aggregate. You do not know which trucks earn and which leak. Per-truck and per-tech margin reporting tells you which routes pay for the truck payment and which are running flat.
The BuildCrux Method for HVAC
Accurate Estimating
AI takeoff on commercial mechanical drawings handles tonnage, zone controls, make-up air, and refrigeration line sets in twelve minutes. Replacement quoting works on mobile with equipment cost and labor. Service-call quotes from the truck.
- AI takeoff on full PDF mechanical sets
- Replacement quoting with equipment cost + labor
- Service-call quick-quote on mobile
Structured Planning
Commercial install schedules tied to GC milestones. Service routes optimized daily. Long-lead equipment flagged at bid time — 8 to 16-week lead times on rooftop units and custom AHUs are normal in 2026.
- Phase budgets inherit from estimate
- Long-lead equipment flagged early
- Service-route daily dispatch
Controlled Execution
Mobile-first field UI. Background GPS mileage on every truck. Photo documentation of equipment serial numbers. Daily logs. Stripe-linked invoicing same-day on service and replacement work.
- Background mileage on every truck
- Photo capture for equipment serial numbers
- Same-day Stripe-linked invoicing
Change Order Management
Customer upgrades from a 14-SEER to a 16-SEER mid-install. CO inherits unit costs from baseline estimate. Customer e-signs. Contract value updates. No friction.
- CO unit costs inherit from baseline estimate
- Customer e-sign from any device
- Schedule and budget sync on approval
Financial Visibility
Per-truck, per-tech, per-customer-segment margin reporting. AR aging. QuickBooks two-way sync.
- Per-truck, per-tech, per-segment margin
- AR aging with automated reminders
- QuickBooks two-way sync
Capability snapshot
| Capability | Why it matters for HVAC |
|---|---|
| AI estimating on commercial mechanical sets | Tonnage + load + line set in 12 minutes |
| Mobile-first field UI | Trucks, not desks |
| Background GPS mileage | Capture every business mile across the fleet |
| Stripe payment processing | Customer pays from the driveway |
| Customer portal e-sign | CO and proposal sign-off without printing |
| QuickBooks two-way sync | Books reconcile without Sunday cleanup |
| Per-truck profitability | Know which routes pay for themselves |
| Photo documentation | Equipment serials, install dates, warranty proof |
Get started with BuildCrux
Built for HVAC service teams, replacement specialists, and commercial mechanical GCs.
Get StartedService vs replacement vs commercial install
| Workflow | Service | Replacement | Commercial install |
|---|---|---|---|
| Bid origination | Phone call, on-truck quote | Same-day driveway quote | PDF mechanical set, AI takeoff |
| Bid time | 5-10 min | 15-30 min | 12 min (AI) vs 12+ hrs (manual) |
| Estimate format | Quick proposal | Equipment + labor + financing | Line-item with quantities + units |
| Approval | Tech captures signature | Customer e-signs | Owner e-signs portal |
| Billing | Same-day Stripe link | Deposit + final | Progress billing per milestone |
| Cash flow | 0-7 days | Deposit immediate, balance net | 14-28 days net |
Case study: 14-employee HVAC GC
A 14-employee HVAC GC in Phoenix doing $5.2M in mixed service ($2.5M), replacement ($1.5M), and commercial install ($1.2M). Was running Service Fusion ($500/month) for service plus a manual estimating spreadsheet for commercial. Spent 8 to 14 hours per commercial bid. Won 1 in 5.
Switched to BuildCrux Enterprise at $999/month flat (vs scaling Service Fusion up further to handle more users). AI estimating cut commercial bid time from 10 hours to 28 minutes. Commercial bid volume doubled. Net new commercial revenue: ~$680K/year. Service-call payment time dropped from 14 days to 4 days. Per-truck margin reporting revealed two trucks were running -2% margin; reassigned routes increased fleet margin 3 points across 8 trucks.
Why HVAC contractors choose BuildCrux
BuildCrux ships service-truck workflows, replacement quoting, AI commercial estimating, and per-truck profitability in one app at flat-tier pricing without per-user scaling. Most HVAC GCs see 4 to 8x return on subscription cost in the first year between commercial bid throughput, faster service-call payment, and fleet-margin visibility.
BuildCrux Feature
AI Blueprint Estimates
AI-powered estimates from your blueprints
Learn moreFrequently asked questions
Does BuildCrux work for HVAC service teams?+
Yes. Mobile-first field UI lets techs quote, invoice, and collect Stripe payments from the truck. Background GPS mileage runs automatically across the fleet.
Can BuildCrux estimate commercial mechanical work?+
Yes. AI takeoff reads full PDF mechanical drawing sets up to 500 MB and produces equipment-and-load-based commercial estimates in twelve minutes.
Is BuildCrux a Service Fusion alternative?+
For HVAC GCs that do mixed service plus commercial install, yes — and BuildCrux costs less at the comparable tier and ships AI commercial estimating Service Fusion does not. Service Fusion goes deeper on pure-service dispatch optimization.
Does BuildCrux handle replacement quoting?+
Yes. Replacement quoting on mobile with equipment cost, labor, financing options, and customer e-sign. Same-day driveway quote with Stripe deposit collection.
How does per-truck profitability work?+
Time entries, expenses, mileage, and revenue route to specific trucks. Margin reports surface per-truck, per-tech, and per-customer-segment. Use it to identify low-margin routes and reassign work.
The bottom line
HVAC has three businesses inside one trade. Software that handles only one forces you to maintain three stacks. BuildCrux handles all three with AI estimating commercial work other tools cannot match.
