Saved 7 million DKK while fireproofing cultural heritage in a single visit
A traditional inspection would point to a new roof costing 7.76M DKK. The drones showed the roof is 63% in good condition and can be maintained for 24,500 DKK/year. On top of that, the parish council got a 3D model of the entire church — inside and out — as a Fire Safety Documentation Archive.
Headline numbers
7.0M DKK
Saving over 30 years
Maintenance vs. a new roof
63%
Roof condition
Intact — not in disrepair
−94%
CO₂ load
Maintenance instead of a new roof
3D
Heritage archive
Interior + exterior
Two deliverables, one drone visit
Deliverable 1
Roof — Damage report
51-page interactive report with 4 roof surfaces, K0–K3 damage classification and a phased 30-year plan. The parish council knows exactly what to do over the next 5 years.
Deliverable 2
Cultural heritage — 3D model of the church
A photogrammetric digital twin — roof, tower, altar, pulpit, organ, frescoes. If the church burns, it can be rebuilt 1:1. This is the Notre-Dame case.
Preserving Heritage in 3D
Explore the church from every angle through an interactive digital twin. Click the model to inspect the roof, tower and heritage details in full 3D.
The simple story — two deliverables, one drone visit
Høje Taastrup Church has a roof with a level of deterioration that could easily lead to a recommendation for full replacement — an investment estimated at 7.76M DKK over a 30-year period.
The drone inspection revealed a different picture. Approximately 63% of the roof remains in good condition, while the documented defects are measurable and distributed across four roof surfaces. Rather than replacing the roof, the required work can be carried out through a phased repair strategy.
The estimated maintenance cost over 30 years is 735,000 DKK — equivalent to approximately 24,500 DKK per year.
"It's not a luxury investment. It's responsible cultural heritage management."
The result is a parish council with a clear five-year action plan and a documented digital record of the church's cultural heritage should the worst happen. Both deliverables were completed during a single drone visit, while services, baptisms and funerals continued without disruption.
The numbers — Damage report, 30-year reference
7.76M DKK for a New Roof — or 0.74M DKK in Maintenance
The key financial finding is straightforward: the documented damage follows typical ageing patterns for a Danish church tile roof. The defects are predictable, measurable and manageable through targeted maintenance by a qualified roofer. There is no technical need for a full roof replacement.
7.0M DKK
Possible saving (91%) in the parish council's funds — 24,500 DKK/year instead of a 7.76M DKK roof project all at once.
Calculated using a 5% annual interest rate and a 30-year reference period in accordance with EN 15978. Engineering hours and design costs are excluded. The figures are DroneTjek's own estimates based on the Damage Report and have not been recalculated through the AssetEye System for this specific church.
Phased Repair Strategy
Three Budget Levels — Not One Major Investment
The phased repair strategy reflects a realistic maintenance backlog. It allows the parish council to manage immediate liquidity needs, medium-term operating expenses and long-term maintenance funding separately.
Phase 1 · 6–12 months
Immediate Actions
Stop water ingress and prevent further deterioration.
- Replace cracked, loose and damaged roof tiles
- Seal and repair defective flashings
- Clean gutters and valley gutters to remove blockages
Phase 2 · 1–3 years
Strategic Maintenance
Planned works that improve long-term roof performance.
- Repair deteriorated ridge boarding and battens
- Renew damaged mortar joints and pointing
- Repair chimney and gable masonry
Phase 3 · 3–5 years
Follow-Up Actions
Maintain roof performance and extend service life.
- Follow up on works completed in Phases 1 and 2
- Surface-treat exposed timber components
- Conduct periodic inspections and minor adjustments
Churches are not ordinary buildings. They are cultural heritage.
The altarpiece, frescoes and historic organ cannot simply be replaced. When Notre-Dame burned in 2019, laser scans captured years earlier became a critical foundation for its reconstruction.
DroneTjek's Damage Report and 3D Archive provide two outcomes in a single visit: a roof maintenance strategy that can save approximately 7 million DKK over 30 years, and a digital heritage record that preserves the information needed to restore the building should the worst happen.
It is not a luxury investment. It is responsible stewardship of cultural heritage.
Tariq Kajjouj
Founder & CEO, DroneTjek ApS
Get Started
Want the same basis for your church?
Let us fly over your church. One flight gives you both a roof maintenance plan and a 3D fire-safety documentation — without disrupting services.
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