The verdict in three sentences
Linking construction tracking, staged (off-plan) payments and a tender document library in one tool is the core need of a developer-builder. An off-the-shelf construction solution costs 35 to 80 EUR per user per month but stays generic; a custom build means 45,000 to 95,000 EUR with 800 to 1,600 EUR/month of maintenance. Custom pays off through milestone alerts that avert costly construction delays.
Off-the-shelf or custom: 2026 comparison
| Criterion | Off-the-shelf | Custom build |
|---|---|---|
| Price | 35-80 EUR/user/mo | 45,000-95,000 EUR |
| Staged payments | standard | modelled on your schedules |
| Tender document library | basic | bespoke tree structure |
| Electronic signature | option | built in |
| Milestone alerts | generic | set per project |
| Accounting integration | limited | native |
| Monthly maintenance | included | 800-1,600 EUR |
The off-the-shelf tool starts fast but imposes its logic. Custom fits your staged-payment schedules and document tree, while integrating electronic signature and accounting.
Breaking down budget and timeline
| Step / module | Effort (person-days) | Indicative budget |
|---|---|---|
| Specification | 8-12 d | 4,500-7,000 EUR |
| Construction tracking + milestones | 15-24 d | 9,000-15,000 EUR |
| Staged payments | 14-22 d | 8,500-13,500 EUR |
| Tender document library | 12-20 d | 7,000-12,000 EUR |
| E-signature + accounting | 10-16 d | 6,000-10,000 EUR |
| UAT + rollout | 8-12 d | 5,000-8,000 EUR |
The specification (3 to 4 weeks) drives the whole project. Overall timeline is 14 to 20 weeks for a budget of 45,000 to 95,000 EUR. Milestone alerts set per project are the highest-ROI module.
Mini case study
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Nadia, project director at a developer-builder, runs 4 sites, one of which regularly slips. One month's delay on a 6,000,000 EUR project is about 35,000 EUR in carried finance costs and penalties. Over a year, cumulative delays cost on the order of 90,000 EUR. A custom build at 68,000 EUR (median) with milestone alerts cuts these delays by 20%, i.e. 18,000 EUR/year saved, plus secured staged payments. The investment pays back in about 3 years on averted delays alone, before counting saved admin time.
FAQ
Why start with a specification? Because it locks scope, staged-payment schedules and the document tree. Budget 3 to 4 weeks and 4,500 to 7,000 EUR, deductible from development.
Is electronic signature included? It integrates natively (works contracts, addenda). It is a 6,000 to 10,000 EUR item together with the accounting link.
How long to deliver? As a 2026 order of magnitude, 14 to 20 weeks after specification sign-off.
What concrete gain on sites? Milestone alerts avert about 20% of delays, worth tens of thousands of euros a year on multi-million projects.
What maintenance to plan? Maintenance of 800 to 1,600 EUR/month, fixes and upgrades included, roughly 15 to 20% of development cost per year.
Let's scope your project. Tell us your number of sites, your staged-payment schedules and your document-library needs, and we will frame the specification and timeline. 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.
