The verdict in three sentences
A developer tracking 250 off-plan units on a spreadsheet shared between sales agents, conveyancing lawyers and sales admin pays for it in late stage payments, overlapping reservations and buyers phoning to ask how construction is going. Off-the-shelf software costs EUR 500 to 2,000 a month, a custom build EUR 40,000 to 90,000 excluding VAT over 4 to 6 months, and the right pick depends mainly on how many schemes you run at once and how your lawyers work. Either way, a buyer portal and automated stage payment calls pay back in under two years on a portfolio this size.
What the spreadsheet cannot do
The unit schedule is usually tidy at launch. Trouble starts with volume: two agents reserve the same two-bed within hours, a signed reservation reaches the lawyer ten days late, a buyer upgrade is agreed by email and never priced. When a construction milestone is certified, sales admin rebuilds by hand what each unit owes. In Spain and Portugal, where many developers sell to buyers living abroad, typical schedules run 10 to 20 % at reservation and contract, 20 to 40 % in stages during construction and the balance at completion, and in Spain stage payments must be guaranteed by a bank guarantee or insurance.
| Feature | Spreadsheet and email | Off-the-shelf software | Custom build |
|---|---|---|---|
| Live unit schedule, prices, statuses | manual, double-booking risk | yes | yes, fitted to your unit types |
| Reservations with automatic expiry | no | yes | yes, rules per scheme |
| Reservation contract and deposit | Word templates | standard templates | generated and e-signed in the tool |
| Stage payment calls per schedule | calculated by hand | yes, standard schedule | yes, with upgrades and discounts built in |
| Buyer portal (documents, progress, payments) | no | often an add-on | yes, under your brand |
| Lawyer workflow | emails and attachments | file export | shared file and signing status |
| Agent and board reporting | weekly consolidation | standard reports | your own KPIs, margin per unit |
Off-the-shelf or custom: five-year cost
New-build sales platforms charge, as a 2026 ballpark, from EUR 500 a month for a small developer to EUR 2,000 a month for a multi-scheme operation, plus onboarding. Custom makes sense when your flows are unusual: bulk sales to investors, mixed residential and retail schemes, several agents paid on different terms, buyers paying in different currencies.
| Option | Setup | Annual cost | 5-year total |
|---|---|---|---|
| Spreadsheet and email | EUR 0 | 0.5 FTE sales admin, about EUR 25,000 | about EUR 125,000 of staff time |
| Off-the-shelf, entry level | EUR 5,000 | EUR 6,000 | EUR 35,000 |
| Off-the-shelf, multi-scheme | EUR 15,000 | EUR 24,000 | EUR 135,000 |
| Custom, tight scope | EUR 40,000 | EUR 6,000 maintenance | EUR 70,000 |
| Custom, full scope with buyer portal | EUR 90,000 | EUR 12,000 maintenance | EUR 150,000 |
Custom wins from about two scheme launches a year, or when you want to own your sales data rather than follow a vendor's roadmap. These are 2026 ballpark figures for European agencies. Kolonell, with a development team based in Dakar, prices this kind of tool on its custom application grid: medium from 4,000,000 to 7,000,000 FCFA (6,100 to 10,670 EUR), complex from 7,000,000 to 15,000,000+ FCFA (10,670 to 22,870+ EUR), depending on modules. Maintenance runs 35,000 to 120,000 FCFA a month (53 to 183 EUR).
How a 4 to 6 month project runs
Month one maps a unit's statuses from available to handed over, and each agent's reservation rules. Months two and three deliver the unit schedule, reservations and contracts, with the spreadsheet migrated. Month four adds stage payment calls and the lawyer workflow. The buyer portal comes last, in months five and six, once the core data is reliable. That order avoids opening a client portal fed by statuses nobody yet trusts.
Mini case study
Miguel, sales director of a developer in Lisbon, tracks 250 units across three schemes at an average price of EUR 380,000, with 60 % of buyers living abroad. About EUR 17,500,000 of stage payments are called each year. The average payment delay is 28 days, because calls go out late and overseas buyers do not always understand the amount. With calls generated on the milestone certificate date and a portal showing the schedule, the delay drops to 10 days. On development finance at 5 %, the cash gain is 17,500,000 × 5 % × 18 / 365, about EUR 43,150 a year.
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Sales admin also saves around 900 hours a year of calculations, reminders and calls, worth EUR 40,500 at EUR 45 an hour fully loaded. Total: about EUR 83,650 a year. For a EUR 65,000 custom build, payback comes in under ten months.
FAQ
Is the payment schedule enforced automatically?
Yes, stage percentages are configured per scheme and the tool blocks any call above the agreed cap. Upgrades and discounts are added to the price before calculation.
Can we migrate our current spreadsheets?
Yes, migration takes 1 to 2 weeks for 250 units, with checks for duplicates and inconsistent statuses. Plan one day of sign-off per scheme on the sales admin side.
Do lawyers have to use the tool?
No. They can receive a complete file through a secure link, and sales admin updates the signing status in 2 clicks.
What does the buyer see in the portal?
Their contract, amendments, schedule with paid and outstanding amounts, progress photos and key dates. On a 100-unit scheme, developers report up to 40 % fewer inbound calls.
How long before a first scheme is live?
The units, reservations and contracts core is usable from month three. The full project with the buyer portal takes 4 to 6 months.
Let's scope your project. In one workshop we map your unit statuses and your agent and lawyer flows, then propose a module-by-module 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.
