The verdict in three sentences
A social landlord with 15,000 homes, 1,500 to 2,500 of them rated EPC F or G, must run hundreds of works sites in parallel, with contractors, tenants in occupation and several funders to reassure. A retrofit tracking web application costs EUR 35,000 to 80,000 (about USD 38,000 to 87,000) and ships in 4 months for a first version. It pays for itself mainly by securing funding and avoiding late re-letting under the French Climate and Resilience Act timetable, a model similar to minimum energy standards elsewhere in Europe.
The timetable that forces tight control
Since 1 January 2025, G-rated homes in France can no longer be offered under a new lease. F-rated homes follow in 2028, then E-rated homes in 2034. For a social landlord, every home not retrofitted on time is a home that cannot be re-let, meaning lost rent and a longer waiting list.
| Deadline | Rating affected | Typical homes (15,000-unit stock) | Consequence if not retrofitted |
|---|---|---|---|
| 2025 | G | 300 to 600 | No re-letting under a new lease |
| 2028 | F | 1,200 to 1,900 | No re-letting under a new lease |
| 2034 | E | 2,500 to 3,500 | No re-letting under a new lease |
| Average retrofit cost | F/G to C or D | EUR 30,000 to 55,000 per home | EUR 50 to 100 million programme over 8 years |
| Voids caused by delays | All ratings | 2 to 4 months per late home | EUR 1,000 to 2,000 of rent lost per home |
The data to collect, home by home
The heart of the application is a single record per home, shared between the asset management team, project officers, contractors and housing management.
| Data | Source | Use | Frequency |
|---|---|---|---|
| Pre-works EPC (rating, kWh/m², CO2) | Assessor, national EPC database | Prioritisation, grant eligibility | Once |
| Works programme by package | Project officer, specifications | Insulation, windows, ventilation, heating | At launch |
| Progress by package and by home | Contractors via mobile, photos | Schedule, penalties, handover | Weekly |
| Tenant appointments and information | Housing management, SMS | Access to the home, satisfaction, complaints | At each visit |
| Committed and paid costs | Finance ERP | Budget tracking per project | Monthly |
| Post-works EPC and energy gain | Assessor | Evidence for funders, energy savings certificates | Once |
| Funding evidence | Project officer | Green loans, energy savings certificates, EU funds, local grants | At each milestone |
Application budget
| Scope | Content | Indicative 2026 cost (EUR, excl. VAT) |
|---|---|---|
| Housing stock core | Stock import, EPCs, home records | 8,000 to 15,000 |
| Mobile site tracking | Progress by package, photos, snags, contractor access | 10,000 to 22,000 |
| Tenant communication | Appointment SMS and emails, tracking page, complaints | 5,000 to 12,000 |
| Funder dashboards | Energy gains, costs, evidence export | 6,000 to 15,000 |
| Integrations | ERP, housing management software, GIS | 6,000 to 16,000 |
A starting scope with core, site tracking and dashboards costs about EUR 35,000 to 45,000. The full version reaches EUR 70,000 to 80,000. Maintenance and local hosting run EUR 10,000 to 15,000 per year.
Mini case study
Marc, director of assets at a social landlord with 15,000 homes, must retrofit 1,600 F and G homes by 2028, at 400 per year. Last year, without shared tracking, 80 homes were re-let with an average delay of 3 months, i.e. 80 × 3 × EUR 420 of rent = EUR 100,800 of lost rent. His teams also spent 2 days per month consolidating reports for funders. With an application at EUR 62,000 and EUR 12,000 of maintenance, he aims to halve delays: about EUR 50,400 of rent recovered per year, plus 24 days of consolidation saved, about EUR 9,000. The project pays back in about 16 months, before even counting more secure energy savings certificate income.
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FAQ
How much does a retrofit tracking application cost?
Between EUR 35,000 and 80,000 depending on modules and integrations. Maintenance runs EUR 10,000 to 15,000 per year.
How long does it take to build?
Budget 4 months for a first version usable on a pilot programme of 50 to 100 homes, then additions by package.
Will contractors have to use the application?
Yes, through simple mobile access: photos and progress in under 2 minutes per home. The obligation can be written into the works contract specifications.
How does the application help secure funding?
It gathers before and after EPCs, invoices and photos per home, which speeds up green loan, energy savings certificate or EU fund claims. Landlords estimate they gain 1 to 2 months on disbursements.
Is the application GDPR compliant for tenants?
It processes contact details and appointments, with local hosting, role-based access and data deletion at the end of the project. A simple impact assessment is recommended.
Let's scope your project. Tell us your stock size, the number of F and G homes to treat and your current tools: we will price an application between EUR 35,000 and 80,000 delivered in 4 months. 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.
