The verdict in three sentences
A custom construction site reporting app with photos, snags pinned on drawings and handover certificates signed on tablet costs 28,000 to 60,000 EUR excl. VAT for an 80-employee main contractor in Dublin. Against market licences at 30 to 60 EUR per user per month, custom-built pays off from 30 active users over 3 years, especially if offline mode and your own handover templates are non-negotiable. The measurable gain is about 4 hours per week per site manager, with a delivery time of 3 months.
Functional scope and its price
With 25 sites running in parallel, snags get lost between phone photos, spreadsheets and emails to subcontractors. The app must centralise this information and work in basements or buildings without signal.
| Module | Content | Indicative 2026 budget (EUR excl. VAT) |
|---|---|---|
| Core and accounts | Roles for site manager, foreman, subcontractor, client | 4,000 to 7,000 |
| Offline mode | Entry without signal, sync and conflict handling | 6,000 to 12,000 |
| Photos and markup | Capture, arrows, dimensions, automatic compression | 3,000 to 6,000 |
| Snags pinned on drawings | PDF or converted DWG import, pins by trade and company | 6,000 to 14,000 |
| Handover certificates and signature | In-house templates, tablet signature, timestamped PDF export | 4,000 to 9,000 |
| Subcontractor reminders | Automatic email, snag close-out link with proof photo | 2,500 to 6,000 |
| Management dashboard | Open snags per site, close-out times, retentions | 2,500 to 6,000 |
| Total | 25 sites, 80 employees | 28,000 to 60,000 |
Add 250 to 600 EUR excl. VAT a month for hosting, photo storage (about 1 TB a year for 25 sites) and corrective maintenance.
Custom-built or market licences
Market tools deploy fast, but costs climb with the number of users and invited subcontractors. The table compares 3 years of use for 35 users (2026 estimate).
| Criterion | Market licence (30 EUR per month) | Market licence (60 EUR per month) | Custom-built |
|---|---|---|---|
| Setup | 2,000 to 5,000 EUR | 3,000 to 8,000 EUR | 28,000 to 60,000 EUR |
| Annual cost (35 users) | 12,600 EUR | 25,200 EUR | 3,000 to 7,200 EUR |
| Total 3-year cost | 39,800 to 42,800 EUR | 78,600 to 83,600 EUR | 37,000 to 81,600 EUR |
| In-house handover templates | Partial | Yes, configurable | Yes, exact |
| Full offline mode | Variable | Yes | Yes |
| Link to your construction ERP | Paid connector or none | Paid connector | Built into the spec |
| Code and data ownership | No | No | Yes |
The tipping point sits around 30 users on a premium licence. Below 15 users, a 30 EUR licence remains the sensible option.
Where the real gain lies
A site manager spends 6 to 8 hours a week on average sorting photos, writing reports and chasing subcontractors. The app brings this down to 2 to 4 hours, about 4 hours saved. Snag close-out also speeds up: the average delay drops from 45 to 20 days, releasing the 5% retention earlier.
Mini case study
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Conor, operations director of an 80-employee main contractor in Dublin, manages 9 site managers. He chooses an app at 42,000 EUR excl. VAT plus 400 EUR a month. Gain: 9 managers x 4 hours x 45 weeks = 1,620 hours a year, valued at 48 EUR per loaded hour, i.e. 77,760 EUR. First-year cost: 42,000 + 4,800 = 46,800 EUR. Payback: about 7 months, not counting retentions released sooner.
FAQ
Does the app work without signal on site?
Yes, all entries are stored on the tablet and synced when signal returns. A tablet easily holds 2,000 compressed photos offline.
Are special tablets required?
No, a rugged Android tablet at 350 to 600 EUR or an iPad in a reinforced case is enough. The app is a PWA, so no app store involved.
Do subcontractors need a paid licence?
No, they get a secure link per snag to close it with a proof photo. No paid account is needed, unlike some licences billed per guest.
Is a handover certificate signed on tablet legally valid?
Yes, a simple electronic signature with timestamp and party identity is admissible under eIDAS for a handover record. For extra assurance, an advanced signature costs 1 to 3 EUR per document through a qualified provider.
Can ongoing sites be migrated?
Yes, importing drawings and existing snags from Excel takes 1 to 2 days per site. We recommend starting with 3 pilot sites for 3 weeks.
Let's scope your project. Give us your number of sites, site managers and your handover templates: we will price the app between 28,000 and 60,000 EUR excl. VAT with a 3-month plan. 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.
