The verdict in three sentences
A 90-employee structural works contractor running 25 sites at once in Berlin, who discovers losses at handover, typically loses 2 to 4 margin points on one site in four. Off-the-shelf software at 50 to 120 EUR per user per month covers estimating, scheduling and invoicing, but a custom build at 45,000 to 110,000 EUR excluding VAT pays off when hours, purchases and progress must be combined into a margin updated every Monday. The success criterion to write into the contract: no overrun above 1 point discovered after the halfway mark of a project.
Why margins drift unseen
Margin on a structural works project depends on labour, concrete and steel purchases, equipment rental and subcontracting. When this data arrives as paper slips and supplier invoices keyed in three weeks late, the site manager flies blind.
| Source of variance | Frequency across 25 sites | Typical margin impact | Detected without a tool | Detected with weekly tracking |
|---|---|---|---|---|
| Hours overrun (pace, weather) | 8 to 10 sites | -1.5 to -3 points | At closing | Week 2 or 3 |
| Off-budget purchases (concrete, steel, formwork) | 5 to 7 sites | -1 to -2 points | At supplier invoice | At order |
| Rented equipment not returned | 4 to 6 sites | -0.5 to -1 point | At year end | Every week |
| Unbilled change orders | 6 to 8 sites | -1 to -2.5 points | Rarely | When the change is logged |
| Subcontracting beyond contract | 2 to 4 sites | -1 to -3 points | At subcontractor invoice | At commitment |
| Delay penalties | 1 to 3 sites | -0.5 to -2 points | At handover | As soon as the schedule slips |
These 2026 estimates apply to projects of 200,000 to 1,500,000 EUR excluding VAT, residential and commercial buildings.
Off-the-shelf or custom: the comparison
| Criterion | Off-the-shelf (50 to 120 EUR per user per month) | Custom (45,000 to 110,000 EUR) |
|---|---|---|
| Yearly cost for 25 users | 15,000 to 36,000 EUR | 9,000 to 16,000 EUR maintenance and hosting |
| Estimating, quantities, GAEB price library | Complete | Usually kept in the existing tool |
| Mobile time tracking | Standard | Tailored to crews, offline, 8,000 to 15,000 EUR |
| Purchasing and commitments | Basic | Linked to orders and delivery notes, 10,000 to 20,000 EUR |
| Progress billing (Abschlagsrechnungen) | Included | With price escalation and 5% retention, 8,000 to 18,000 EUR |
| Weekly margin per site | Monthly report | Automatic dashboard, 9,000 to 20,000 EUR |
| Accounting and payroll connection | Export | Sync, including XRechnung e-invoices, 5,000 to 12,000 EUR |
| Timeline | 1 to 3 months | 4 to 7 months |
The most common path: keep the existing estimating tool and commission time tracking, purchasing and the margin dashboard for 35,000 to 60,000 EUR.
Mini case study
Thomas, managing director of a 90-employee structural works contractor in Berlin, generates 12,000,000 EUR in revenue with a 9% target margin. One site in four ends on average 3 points below target, discovered too late.
- Custom project: mobile time tracking, purchasing, progress billing and margin dashboard for 75,000 EUR, plus 12,000 EUR a year.
- Drift: 12,000,000 EUR × 25% × 3 points = 90,000 EUR lost a year. If weekly tracking corrects half, estimated gain of 45,000 EUR.
- Change orders: 0.3% of revenue billed additionally, 36,000 EUR.
With about 81,000 EUR of yearly gains, the project pays back in just over 12 months.
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FAQ
How much does custom construction management software cost in 2026?
From 45,000 to 110,000 EUR excluding VAT depending on modules, including 8,000 to 15,000 EUR for mobile time tracking. Annual maintenance runs 12 to 15% of the project.
Will crews accept clocking in on a phone?
Yes if entry takes under 30 seconds and works offline. Having the foreman log hours for the whole crew is often the most adopted approach.
Can we keep our estimating software?
Yes, the custom build connects to the existing tool to pull budgets per project. This cuts the project scope by 20 to 30%.
How are progress invoices and retention handled?
The software calculates progress, price escalation and the usual 5% retention under VOB/B contracts. The monthly progress invoice then takes one hour instead of half a day.
When do the first gains appear?
On projects started after go-live, 2 to 3 months after launch. Gains on ongoing projects are smaller because their budgets are already committed.
Let's scope your project. Send us your number of sites, current tools and main sources of overrun, and we will price a scope between 35,000 and 110,000 EUR with a 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.
