The verdict in three sentences
For a 1,500-employee headquarters in Dublin moving to hybrid working, a custom desk and room booking app costs 40,000 to 90,000 EUR, delivered in 8 to 12 weeks. An off-the-shelf SaaS at 3 to 6 EUR per user per month comes to 36,000 to 72,000 EUR per year for 1,000 active users, so custom can break even within 1 to 2 years at this scale. The real gain is not software: it is the measured occupancy rate that lets you give back around 20% of floor space, worth hundreds of thousands of euros in rent each year.
Hybrid office in Dublin: what occupancy data changes
In Dublin's Docklands and city centre, prime Grade A office rent sits around 550 to 700 EUR per m² per year in 2026 (order of magnitude). With hybrid working, occupancy studies commonly show that only 40 to 55% of desks are in use on any given day.
| Indicator | Before hybrid booking (estimate) | After 6 months of measured booking |
|---|---|---|
| Desks | 1,500 | 1,100 to 1,200 (ratio 0.75 to 0.8) |
| Total floor area | about 15,000 m² | about 12,000 m² (down 20%) |
| Average desk occupancy | 45% | 65 to 75% |
| Meeting room occupancy | 30% (booked, often empty) | 55 to 65% (automatic release) |
| Ghost room bookings | 25 to 35% | under 10% |
| Annual rent at 600 EUR per m² | 9,000,000 EUR | 7,200,000 EUR |
The condition: reliable data. Without an app, facilities managers decide on impressions, and lease renegotiations or floor consolidations are done blind.
Custom or SaaS: costed comparison for 1,500 employees
| Criterion | Off-the-shelf SaaS | Custom application |
|---|---|---|
| Upfront cost | 2,000 to 6,000 EUR of rollout | 40,000 to 90,000 EUR |
| Licence | 3 to 6 EUR per user per month | None |
| Annual cost for 1,000 active users | about 36,000 to 72,000 EUR | Maintenance and hosting 8,000 to 18,000 EUR |
| 3-year cost | about 110,000 to 220,000 EUR | about 64,000 to 144,000 EUR |
| Microsoft 365 integration (Outlook, Teams) | Usually native | To build, 4 to 6 weeks included |
| Badge and access control integration | Depends on badge vendor | Custom, using the existing system's API |
| EU data residency (GDPR) | Varies by vendor | Your choice of EU region |
| Time to go live | 3 to 6 weeks | 8 to 12 weeks |
2026 estimates. SaaS remains a good choice for a quick pilot on a single floor or building. Above roughly 800 active users, cumulative licence cost usually overtakes a custom build within 2 years.
Must-have modules and Microsoft 365 integration
A realistic scope within the 40,000 to 90,000 EUR range:
- Interactive floor plans for every floor, with desks, rooms, lockers and parking spaces.
- Booking from web, mobile and directly from Outlook and Teams via Microsoft Graph, with single sign-on through Entra ID.
- Check-in by QR code at the desk or by badge swipe: a booking not confirmed within 15 minutes is released automatically.
- Business rules: neighbourhoods per department, team days, desks reserved for managers or for accessibility needs.
- Occupancy dashboard: rates per floor, day and department, heatmaps, export for the real estate committee.
- Compliance: GDPR data protection impact assessment, limited retention of attendance data and anonymised statistics.
Badge system integration often accounts for 20 to 30% of the budget, because it depends on the incumbent access control vendor's API.
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Ciara, head of facilities at a 1,500-employee group in Dublin, occupies 15,000 m² at 600 EUR per m² per year, or 750,000 EUR of rent per month.
She commissions an app at 70,000 EUR, with maintenance and hosting at 1,200 EUR per month. After 6 months of data, she gives back one and a half floors, 1,500 m² (a cautious 10%): saving 1,500 x 50 = 75,000 EUR per month. First-year cost: 70,000 + 14,400 = 84,400 EUR. Savings over the last 6 months of the year: 450,000 EUR. The project pays back in the second month after the space is released. Illustrative scenario, to check against your lease terms.
FAQ
Do we need sensors on every desk?
No. QR code or badge check-in is enough in most cases. Occupancy sensors cost 60 to 150 EUR per desk and are mainly justified for meeting rooms.
Will employees actually book?
Yes, if booking takes 2 clicks from Outlook or Teams. Well-run rollouts reach 80 to 90% adoption in 6 to 8 weeks.
What are the GDPR obligations?
Attendance data is personal data: a DPIA, employee information, limited retention (often 3 to 6 months when identifiable) and anonymised statistics.
Can we start with a single building or floor?
Yes, and it is recommended. A 2-month pilot with 500 employees validates the rules before full rollout.
How long to measure a reliable occupancy rate?
Allow 8 to 12 weeks of data outside holiday periods to get an average you can use in a lease renegotiation.
Let's scope your project. Send us your headcount, sites and rooms, plus your tools (Microsoft 365, badges), and we will propose a scope, a budget and a pilot schedule. 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.