Spreadsheet or Expense-Tracking App for a Custom Build?

I am comparing two systems for tracking expenses on a custom home build: a structured spreadsheet and a dedicated construction-expense tracking app.

The project is likely to generate approximately 25 to 40 invoices, receipts, or payment records per month during the busiest phases. The builder already provides an online payment and change-order portal, but it may not provide a complete view of subcontractor costs, owner-purchased items, allowances, deposits, and projected final costs in one place. I would therefore need to reconcile the builder’s records rather than assume an app could import everything accurately.

The spreadsheet option would be inexpensive and highly flexible. I could create separate fields for category, construction phase, vendor, committed amount, amount paid, remaining balance, approved change orders, and forecast-to-complete. It would also be straightforward to compare the original budget with actual and projected costs. The drawbacks are manual data entry, receipt organization, version control, and the risk of overlooking an invoice or entering a change-order amount inconsistently.

A tracking app could reduce administrative work through receipt photos, searchable records, reminders, and shared access for a spouse, project manager, or accountant. It might also make budget-versus-actual reporting easier. However, the subscription cost and setup effort are factors, and I would want to confirm that it supports custom categories, phases, vendors, committed costs, unpaid invoices, and forecasts rather than only recording completed payments. Receipt capture would be useful, but it would not solve the need to verify builder statements and change orders.

Offline backup is also important. With a spreadsheet, I could maintain periodic exports as Excel and PDF files, plus a separate cloud and local backup. For an app, I would want to know whether the data and receipt images can be exported in a usable format if the subscription ends or the service becomes unavailable.

For those who have managed a similar volume of construction transactions, did an app’s automation and receipt capture justify the subscription and setup effort? Or did a well-designed spreadsheet remain more reliable? I would especially appreciate examples of how you tracked committed, paid, and forecast costs while avoiding duplicate entries from the builder’s payment portal.