The verdict in three sentences
For a construction leader in 2026, three routes compete: vertical SaaS (fast, standard, per-seat cost), Odoo Construction (modular, open, needs integration) and custom build (aligned, no per-seat fee, funded upfront). The right choice depends not on sticker price but on your jobsite size, accounting/payroll integrations and tolerance for vendor lock-in. Under 15 seats vertical often wins; beyond that, or once reversibility matters, Odoo or custom retake the lead.
The three routes, costed
2026 order of magnitude for a construction firm, before discounts.
| Criterion | Vertical SaaS | Odoo Construction | Custom |
|---|---|---|---|
| Recurring price | EUR 30-60/user/mo | EUR 25-45/user/mo | EUR 0/seat |
| Upfront cost | Low | EUR 12,000-35,000 integration | EUR 45,000-90,000 |
| Time to launch | 2-6 weeks | 2-4 months | 4-6 months |
| Customization | Limited | High (open source) | Total |
| Vendor lock-in | High | Medium | Low |
| Reversibility / export | Variable | Good | Total |
The decision table
Choose by the factor that weighs most in your firm, not by trend.
| Your situation | Recommendation |
|---|---|
| < 15 users, standard need | Vertical SaaS |
| Strong accounting/payroll link, tight budget | Odoo Construction |
| Owned margin analytics, > 25 seats | Custom |
| Multi-entity, reversibility critical | Custom |
| Fast start, market test | Vertical SaaS |
| Existing ecosystem to connect | Odoo Construction |
At 30 users, a EUR 45/month SaaS costs ~EUR 16,200/year recurring, nearly EUR 49,000 over 3 years — custom becomes competitive while removing lock-in and per-seat cost.
Mini case study
Anna, who runs a construction firm in Berlin with 28 users, is undecided. On vertical SaaS at EUR 45/month she pays ~EUR 15,100/year, about EUR 45,000 over 3 years, never owning the tool. Odoo Construction would cost ~EUR 25,000 of integration then ~EUR 12,600/year in licenses. A custom build at EUR 70,000 caps her 3-year TCO at ~EUR 82,000 but removes per-seat cost and gives owned margin analytics. Since she targets 45 users within 3 years, custom becomes most profitable from year 2.
FAQ
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When is vertical SaaS the best choice?
Under 15 users, with a standard need and a fast start. Per-seat cost stays bearable and the 2-6 week timeline lets you test usage before any heavy commitment.
Is Odoo Construction really cheaper?
On licenses yes (EUR 25-45/user/month), but add EUR 12,000-35,000 of integration. It shines when you have strong accounting/payroll integrations and an existing ecosystem to connect.
When to switch to custom?
From 25-30 seats, or when owned margin analytics and reversibility become strategic. At that point, the absence of per-seat cost tilts TCO in its favor over 3 to 4 years.
What is reversibility worth?
A lot when changing vendor: a SaaS with limited export can cost weeks of data migration. Custom and Odoo (open source) offer far higher reversibility.
Can you start SaaS then migrate to custom?
Yes, a common strategy: validate processes on SaaS, then internalize custom once seat count and margin needs justify it. Plan data export from day one.
Let's scope your project. Give us your target seat count, accounting/payroll integrations and indicative budget, and we'll build the costed decision table for your case. 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.
