The verdict in three sentences
With minimum energy standards tightening for rentals (in France, G-rated homes banned from letting in 2025, F in 2028 and E in 2034; in the UK and Ireland, EPC and BER requirements on sales and lets), energy certificates now gate sales and tenancies, and agents and solicitors expect reports within 48 h. Accredited assessment software (EUR 50 to 120 per assessor per month) produces the certificate but handles neither agent ordering, optimised scheduling nor reminders. A custom layer at EUR 25,000 to 50,000 excl. VAT, plugged into that software, cuts delivery from 5 days to 2 and retains the agents who send the volume.
The bottleneck is not the assessment
In the field, an assessor completes 3 to 5 jobs a day. The time lost sits around the visit: orders arrive by phone, email and text, the office retypes address, floor area and the list of surveys, finds a slot, calls the owner about keys, then chases documents (energy bills, floor plans). After the visit, the report waits for invoicing and manual sending.
| Indicator (12-assessor firm) | 2026 order of magnitude | Comment |
|---|---|---|
| Jobs per year | 9,000 to 12,000 | Energy certificate plus related surveys |
| Average sale job value | EUR 250 to 450 excl. VAT | Full apartment pack in Lyon; UK EPC alone is lower |
| Office time per job | 20 to 35 min | Ordering, scheduling, reminders, sending |
| Average report delivery time | 4 to 6 days | From order |
| Share of orders from agents and solicitors | 55 to 75% | Recurring referrers |
| Bad debt and late payment | 3 to 6% of revenue | Manual invoicing after sending |
The options compared in 2026
| Criterion | Accredited software alone | Accredited software + generic tools | Accredited software + custom layer |
|---|---|---|---|
| Upfront cost | Included | EUR 1,000 to 4,000 setup | EUR 25,000 to 50,000 excl. VAT |
| Recurring cost | EUR 50 to 120 per assessor per month | + EUR 20 to 60 per user per month | + EUR 300 to 700 per month |
| Certificate production and calculation engine | Yes | Yes | Yes, unchanged |
| Ordering portal for agents and solicitors | No | Generic form | Yes, with job tracking and documents |
| Scheduling by area and qualifications | Basic | Shared calendar | Yes, routes by district |
| Automatic reminders (documents, payment) | No | Partial | Yes, by email and SMS |
| Invoicing and online payment on delivery | Partial | Partial | Report released on payment or billed to referrer |
| Report delivery time | 4 to 6 days | 3 to 5 days | 1 to 2 days |
The key decision is not to rebuild the calculation engine: it is accredited (by ADEME in France, through approved methodologies such as RdSAP in the UK and DEAP in Ireland) and must stay that way. The layer pulls job data and reports through the vendor's exports or API and handles everything before and after the visit.
What the layer includes
| Module | Indicative budget (EUR excl. VAT) | Timeline |
|---|---|---|
| Referrer ordering portal | 6,000 to 12,000 | 4 weeks |
| Assessor scheduling and routes | 5,000 to 10,000 | 4 weeks |
| Document collection and reminders | 3,000 to 6,000 | 2 weeks |
| Invoicing, online payment, debt chasing | 4,000 to 9,000 | 3 weeks |
| Connection to accredited software | 4,000 to 8,000 | 3 weeks |
| Referrer dashboard, training | 3,000 to 5,000 | 2 weeks |
Mini case study
Julien runs a 12-assessor firm in Lyon handling 10,500 jobs a year at an average EUR 320 excl. VAT. The custom layer, budgeted at EUR 38,000, cuts office time from 28 to 12 minutes per job: 2,800 hours saved a year, about EUR 70,000 of loaded cost redeployed. Delivery drops to 2 days and the portal retains his agents: he wins 6% more jobs, 630 jobs and about EUR 200,000 of revenue. Bad debt falls from 4% to 1.5% of revenue. With EUR 6,000 of annual maintenance, the project pays back in under 4 months.
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FAQ
How much does custom software for an energy assessment firm cost in 2026?
A full layer costs EUR 25,000 to 50,000 excl. VAT, plus EUR 300 to 700 a month for maintenance and hosting. Your accredited software subscription, EUR 50 to 120 per assessor, stays the same.
Do we need to drop our accredited software?
No, certificates must still be calculated by accredited software. The layer connects to it and handles ordering, scheduling, reminders and invoicing.
Will estate agents really use the portal?
Yes if ordering takes under 2 minutes and tracking saves them phone calls. In equipped firms, 60 to 80% of referrer orders go through the portal after 3 months.
Can report delivery depend on payment?
Yes for private clients, with online card payment before the report is released. For agents and solicitors, grouped monthly invoicing remains possible, with an automatic reminder at day 15.
How long does setup take?
Three to five months, with the ordering portal and scheduling live by week six. Migration of referrers and job history is included.
Let's scope your project. Tell us your job volume, accredited software and main referrers: we will price a layer between EUR 25,000 and 50,000 with a 3 to 5 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.