The verdict in three sentences
An architecture firm loses its margin when time spent exceeds the per-phase fee without anyone noticing in time. A vertical SaaS (30 to 70 EUR/user/month) suits standard firms; custom software (40,000 to 120,000 EUR, 5 to 9 months lead time) wins when your phases, fee breakdown or accounting integration fall outside the mould. The core stake: tracking in real time the respect of per-phase fees (schematic, detailed design, construction documents, site).
Modules of an architecture-firm tool
An architecture-agency tool ties together project tracking, per-phase fees, time entry, subcontractors and progress billing.
| Module | Covered by vertical SaaS | Custom stake |
|---|---|---|
| Per-phase project tracking | Yes | Rare |
| Per-phase fees (schematic/detailed/CD) | Partial | Frequent with own breakdown |
| Per-project time entry | Yes | Rare |
| Real-time margin tracking | Basic | Frequent |
| Subcontractor / engineering mgmt | Partial | Often useful |
| Progress billing | Yes | Sometimes (mixed rules) |
| Accounting integration | Limited connectors | Often decisive |
SaaS vs custom: the 2026 budget
For a 10-person firm, the trade-off hinges on margin-tracking granularity and accounting integration. 2026 order of magnitude.
| Criterion | Vertical SaaS | Custom |
|---|---|---|
| Cost per staff / month | 30 to 70 EUR | 0 EUR |
| Year 1 cost (10 users) | 3,600 to 8,400 EUR | 40,000 to 120,000 EUR |
| Accounting integration | 2,000 to 8,000 EUR | Included in scope |
| Per-phase fee tracking | 70 to 85 % | 100 % |
| Real-time margin tracking | Basic | Full |
| Time to go-live | 4 to 8 weeks | 5 to 9 months |
| 5-year TCO (10 users) | 25,000 to 60,000 EUR | 55,000 to 150,000 EUR |
Below 10 staff and without atypical fee breakdown, the vertical SaaS wins. Custom is justified beyond that, or when per-phase margin tracking becomes strategic to your profitability.
Mini case study
Élise runs a 10-person architecture firm in Lyon, 14 active projects, average fee 120,000 EUR/project. In 2025, her untracked time overruns ate on average 7 % of margin per project, i.e. 8,400 EUR × 14 = 117,600 EUR of lost margin. With a custom tool tracking time spent against each phase fee in real time, she reacts before the overrun and targets cutting the loss to 3 %. Gain: about 67,000 EUR/year. An 85,000 EUR build pays back in 15 months, while firming up her progress billing.
FAQ
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Is a vertical SaaS enough for an 8-architect firm?
Often yes: at 30-70 EUR/user/month, it covers project tracking, time and billing. Custom becomes relevant if your per-phase fee breakdown or accounting integration are specific.
How does software prevent fee overruns?
By comparing entered time in real time against each phase's budgeted fee (schematic, detailed, construction documents). An alert past a threshold (say 80 % of the fee consumed) lets you act before the margin slips.
How much does the margin-tracking module cost in custom?
Per-phase and per-project margin tracking generally represents 10,000 to 25,000 EUR in a custom project, depending on detail and the number of subcontractor rebilling scenarios.
Is accounting integration essential?
Not mandatory but highly profitable: it avoids double entry between progress billing and accounting, and firms up the real costs used for margin. It is often the trigger for custom.
How long for a custom architecture-firm tool?
Expect 5 to 9 months depending on scope: scoping, then 2-week sprints. A first version focused on phase and time tracking can ship in 3 to 4 months.
Let's scope your project. Tell us your staff count, per-phase fee breakdown and accounting tool, and we will price SaaS vs custom with a 5-year TCO. 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.
