The verdict in three sentences
A custom construction site management platform costs between 55,000 and 150,000 EUR in 2026, depending on the module count and the field mobile app. The main gain is not the software itself but the 15-25 % reduction in delays and the end of progress billings re-entered three times over. For a firm running more than 8 simultaneous sites, the investment pays back in 10 to 16 months.
Why generic tools no longer cut it
A shared spreadsheet and an accounting ERP do not speak the language of the field: work packages, progress billings, snagging reserves, change orders, subcontractors, timestamped photos. The site manager then spends evenings re-entering what the foreman scribbled on paper. A dedicated platform captures data once, at the source, through a mobile app that works even with no network on site.
The three most expensive pain points custom software addresses:
- Poorly tracked progress billings that delay invoicing by 3 to 6 weeks.
- Handover reserves lost between the paper report and subcontractor follow-up.
- Package-level budget tracking invisible until the site closeout, when it is too late.
Modules and 2026 budget
| Module | What it covers | 2026 ballpark (EUR) |
|---|---|---|
| Multi-site planning | Gantt, milestones, crew assignment | 9,000 - 18,000 |
| Progress billings | Package progress, invoicing, change orders | 12,000 - 26,000 |
| Snagging / reserves | Reports, photos, subcontractor chasing | 8,000 - 16,000 |
| Field mobile app | Offline mode, timestamped photos, clock-in | 14,000 - 30,000 |
| Package budget tracking | Spend vs budget, forecast margin | 10,000 - 22,000 |
| Subcontractor management | Contracts, insurance, billings | 7,000 - 15,000 |
| Accounting/payroll integration | Export to Sage, Cegid, payroll | 6,000 - 14,000 |
A useful core (planning + progress billings + field mobile) starts around 55,000 EUR. A full platform for a multi-program developer reaches 150,000 EUR, over a 5 to 8 month timeline.
ROI: where the money comes back
| Gain area | Current situation | With the software | Estimated annual gain |
|---|---|---|---|
| Site manager reporting | 6 h/week re-entry | 1.5 h/week | 4.5 h x 45 wk x 6 people |
| Average invoicing delay | 4-6 weeks | 1-2 weeks | Cash flow + 15 to 20 % |
| Site delays | Baseline | -15 to -25 % | Penalties avoided |
| Billing errors | 5-8 % of packages | < 2 % | Margin preserved |
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For a firm with 6 site managers, 4.5 hours saved per week per person equals roughly 1,215 hours a year, the equivalent of more than half a full-time role redeployed onto production.
Mini case study
Thomas runs a 45-employee structural works firm near Lyon, with 11 active sites. His site managers lose 6 h/week to reporting and he invoices progress billings 5 weeks late on average. He invests 74,000 EUR in a planning + billings + reserves + mobile app core.
Over 12 months: invoicing accelerated by 3 weeks (average cash flow improved by 180,000 EUR), 1,200 reporting hours saved (worth ~38,000 EUR in productive time), and two late penalties avoided (~22,000 EUR). The project pays back in 13 months excluding the cash-flow gain.
FAQ
Do I really need custom software rather than an off-the-shelf tool? No, if your processes are standard a market construction tool at 40-120 EUR/user/month is enough. Custom pays off beyond 15-20 users or when your progress billings follow a specific logic the vendor refuses to build.
Is offline mode really essential? Yes, on site. Many sites have no reliable network; the app must store photos and clock-ins locally then sync on reconnection, otherwise crews stop using it within 2 weeks.
How long to go live? Allow 5 to 8 months for a full scope, with a first usable version on a pilot site by month 3. A site-by-site rollout sharply reduces risk.
How do I handle accounting integration? A connector to Sage, Cegid or your payroll tool costs 6,000 to 14,000 EUR. It is one of the most profitable items because it removes double entry of billings and hours.
Who owns the code once delivered? On a custom project you must require full ownership of the source code plus documentation. That is what keeps you from being locked in to one vendor for every future change.
Let's scope your project. Tell us your number of sites, your priority modules (billings, reserves, field app) and an indicative budget, and we will frame a core that pays back within the first year. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
