Short answer: ERP for a renovation contractor should be built around projects. Phase one covers project budgets, purchasing, subcontractor payments and project margin in about 16–20 weeks for NT$550K–950K. The goal is to see each project's profit weekly instead of discovering it at month-end close.
Background and pain points: profit per project is known only at month-end
The core problem is that costs are scattered, so no one can see a single job's margin in real time. (A scenario case based on common project needs, not a specific client.) A 25-person interior renovation firm runs 12–15 residential and commercial jobs at once with about 20 subcontractor crews. Today:
- Each job's quote and budget lives in its own Excel file, often in 3–4 versions.
- Designers order materials in LINE groups, suppliers ship straight to sites, and delivery notes reach accounting at month-end.
- Subcontractor claims arrive on paper or as LINE photos, and accounting spends 4–5 days a month reconciling.
- Last year, 3 jobs had unrecorded change orders that surfaced as losses only at settlement.
Requirements: 4 modules in phase one, progress billing and warranty in phase two
Build the 4 modules that directly produce margin first and leave the rest for phase two.
| Module | Owner | Phase |
|---|---|---|
| Project budget (with change orders) | Design, site management | Phase 1 |
| Purchase requests and orders (direct-to-site) | Site management, purchasing | Phase 1 |
| Subcontractor payments (by progress) | Site supervisors, accounting | Phase 1 |
| Project margin reports | Owner, accounting | Phase 1 |
| Client installment billing | Accounting | Phase 2 |
| Warranty and repair requests | Site management, service | Phase 2 |
Why custom: the process centers on job sites, while packaged ERP centers on inventory
The firm chose custom because most packaged ERP is designed around item numbers and stock, while renovation revolves around sites and budgets. Comparison:
- Packaged ERP: mature accounting and invoicing, but direct-to-site deliveries and progress-based subcontractor claims need workarounds.
- Open-source ERP: free licenses, but you need consultants who know it, and small Taiwanese cases are rare.
- Custom: designed around current workflows with a usable site app, but higher upfront cost and someone must own requirements.
To be honest: if your firm mainly sells standardized cabinets or materials, has simple site workflows, or earns under NT$30M a year, packaged ERP or project management SaaS plus accounting software is better value.
Architecture and integrations: back office, site app, LINE and accounting each have a role
The principle is “enter once on site, roll up automatically in the back office.”
- Laravel back office: budgets, purchasing, claims, margin reports and permissions, with an owner dashboard.
- Flutter site app: supervisors post progress photos, confirm deliveries and create claims for crews.
- LINE notifications: purchase approvals, delivery confirmations and claim decisions pushed to the right people.
- Accounting and invoices: voucher exports for existing accounting software; input invoices can be checked against Taiwan's Ministry of Finance e-invoice platform.
Rollout and timeline: 5 phases over 16–20 weeks
The longest part is unifying budget categories, not coding.
| Phase | Weeks | Deliverables |
|---|---|---|
| Interviews and category cleanup | 1–3 | Budget category list, process maps |
| Design and prototype | 4–6 | Clickable back office and app prototypes |
| Development | 7–14 | Staging demo every 2 weeks |
| Pilot | 15–17 | 3 new jobs run in parallel with old methods |
| Full launch | 18–20 | All new jobs in the system, training videos |
Cost breakdown: reserve budget for hidden costs
The total is about NT$550K–950K, plus some often-missed items:
- Back office, 4 modules: NT$400K–650K.
- Flutter site app (iOS/Android): NT$120K–250K.
- LINE and accounting export integration: NT$30K–50K.
- Hosting and backups: about NT$2,000–4,000 a month; app store fees extra.
- Maintenance: from NT$2,000 a month.
- Hidden costs: internal time to clean old job data and unify categories, about 1 person for 3 weeks.
Post-launch targets: 30/60/90 days
- Day 30: all new job budgets and purchase requests in the system; LINE ordering below 20%.
- Day 60: subcontractor claim reconciliation down from 4–5 days to 1–2.
- Day 90: automatic per-job margin every Monday; 100% of change orders recorded.
Pitfalls and fixes: the 5 most common problems
- Inconsistent budget categories: unify 30–50 categories before building, or reports won't add up.
- Verbal change orders: the system counts a change only after client confirmation, with a signature or LINE screenshot.
- Forcing old jobs in: migrate only active jobs; keep closed ones in Excel for lookup.
- Supervisors resist extra entry: keep each app screen to 5 fields; a photo completes a report.
- Owners only see totals: the dashboard defaults to jobs below target margin so problems surface automatically.
FAQ
Does a renovation company really need ERP?
It's worth it with 5+ concurrent projects and 10+ subcontractor crews. With fewer jobs, project tools plus accounting software suffice.
How much does renovation ERP cost?
Phase one's 4 modules run about NT$550K–950K over 16–20 weeks. Maintenance starts at NT$2,000 a month; integrations are extra.
Can't we use packaged construction ERP?
Large builders can. Small renovation firms often find it too heavy and mismatched, so no one uses it after rollout.
What if subcontractors won't use an app?
Site supervisors can file payment claims for them; crews just confirm a LINE notification, keeping the learning curve low.
How soon can we see per-project margin?
Within the first month once budgets and claims are entered. Full accuracy usually takes 2–3 months of actual costs.
Next step: map your job-site workflow first
Custom development at ScriptWalker (a Taiwan-based Laravel/Flutter custom development studio) starts at NT$80,000, and ERP runs about NT$150K–1.5M over 16–24+ weeks depending on scope. If you manage job costs with Excel and LINE, book a 30-minute online consultation and we'll help you decide between custom, hybrid or packaged:
- Email: [email protected]
- Phone: 0916-224-047
- LINE: @ufv9089p