Estimate construction costs from text, photos and PDFs with Telegram, GPT‐4/Gemini and DDC CWICR

A full-featured Telegram bot that accepts text descriptions, photos, or PDF floor plans and returns detailed cost estimates with work breakdown. Powered by GPT-4 Vision / Gemini 2.0, vector search, and the open-source DDC CWICR database (55,000+ construction rates).

Who's it for

• Contractors & Estimators who need estimates from any input format
• Construction managers evaluating scope from site photos or drawings
• Architects getting quick cost feedback on floor plans
• Real estate professionals assessing renovation costs
• Project managers doing rapid feasibility checks via mobile

What it does

1. Receives text / photo / PDF via Telegram
2. Analyzes input with AI (Gemini 2.0 Flash or GPT-4 Vision)
3. Extracts work items with quantities and units
4. Searches DDC CWICR vector database for matching rates
5. Generates professional HTML report with full cost breakdown
6. Exports results as Excel or PDF

Supports 9 languages: 🇩🇪 DE · 🇬🇧 EN · 🇷🇺 RU · 🇪🇸 ES · 🇫🇷 FR · 🇮🇹 IT · 🇵🇱 PL · 🇧🇷 PT · 🇺🇦 UK

How it works

┌─────────────────────────────────────────────────────────────────────┐
│ TELEGRAM INPUT │
│ 📝 Text Description │ 📷 Construction Photo │ 📄 PDF Floor Plan │
└─────────────────────────────────────────────────────────────────────┘
 ↓
┌─────────────────────────────────────────────────────────────────────┐
│ MAIN ROUTER │
│ Parse message → Detect content type → Route to handler (17 actions) │
└─────────────────────────────────────────────────────────────────────┘
 ↓
 ┌──────────────────────────┼──────────────────────────┐
 ↓ ↓ ↓
┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
│ Text LLM │ │ Vision API │ │ Vision PDF │
│ Parse works │ │ Analyze photo │ │ Read floor plan│
│ from text │ │ GPT-4/Gemini │ │ Gemini 2.0 │
└─────────────────┘ └─────────────────┘ └─────────────────┘
 └──────────────────────────┼──────────────────────────┘
 ↓
┌─────────────────────────────────────────────────────────────────────┐
│ CALCULATION LOOP │
│ For each work item: │
│ 1️⃣ Transform query → 2️⃣ Optimize search → 3️⃣ Get embedding │
│ 4️⃣ Qdrant search → 5️⃣ Score results → 6️⃣ AI rerank → 7️⃣ Calculate │
└─────────────────────────────────────────────────────────────────────┘
 ↓
┌─────────────────────────────────────────────────────────────────────┐
│ OUTPUT │
│ 📊 Telegram message │ 🌐 HTML Report │ 📑 Excel │ 📄 PDF │
└─────────────────────────────────────────────────────────────────────┘

Input Types

Type	Description	AI Used
📝 Text	Work lists, specifications, notes	OpenAI GPT-4
📷 Photo	Construction site photos (up to 4)	GPT-4 Vision / Gemini
📄 PDF	Floor plans, architectural drawings	Gemini 2.0 Flash

Route Actions (17 total)

#	Action	Description
0	show_lang	Language selection menu
1	ask_photo	Request photo upload
2	lang_selected	Save language preference
3	show_analyze	Photo analysis options
4	analyze	Run AI vision analysis
5	show_edit_menu	Edit work quantities
6	works_updated	After quantity change
7	ask_new_work	Add manual work item
8	start_calc	Start cost calculation
9	show_help	Display help message
10	view_details	Show resource details
11	export_excel	Generate CSV export
12	export_pdf	Generate PDF export
13	process_pdf	Analyze PDF floor plan
14	analyze_text	Parse text description
15	refine	Re-analyze with context
16	fallback	Handle unknown input

Prerequisites

Component	Requirement
n8n	v1.30+ with Telegram Trigger
Telegram Bot	Token from @BotFather
OpenAI API	For embeddings + text parsing
Gemini API	For Vision (photos/PDF) — or use GPT-4 Vision
Qdrant	Vector DB with DDC CWICR collections
DDC CWICR Data	github.com/datadrivenconstruction/DDC-CWICR

Setup

1. Configure 🔑 TOKEN Node

{
 "bot_token": "YOUR_TELEGRAM_BOT_TOKEN",
 "AI_PROVIDER": "gemini",
 "GEMINI_API_KEY": "YOUR_GEMINI_KEY",
 "OPENAI_API_KEY": "YOUR_OPENAI_KEY",
 "QDRANT_URL": "http://localhost:6333",
 "QDRANT_API_KEY": "YOUR_QDRANT_KEY"
}

2. Vision Provider Selection

• AI_PROVIDER: "gemini" → Gemini 2.0 Flash (recommended for photos + PDF)
• AI_PROVIDER: "openai" → GPT-4 Vision (photos only)

3. n8n Credentials

1. Settings → Credentials → Add → Telegram API
2. Enter bot token, save
3. Select credential in Telegram Trigger node

4. Qdrant Collections

Load DDC CWICR embeddings for target languages (example for Russian):

RU_STPETERSBURG_workitems_costs_resources_EMBEDDINGS_3072_DDC_CWICR

5. Activate & Test

1. Activate workflow
2. Send /start to your bot
3. Select language → send photo/text/PDF

Features

Feature	Description
📷 Photo Analysis	GPT-4 Vision or Gemini 2.0 for site photos
📄 PDF Processing	Floor plan analysis with room extraction
📝 Text Parsing	Natural language work lists
🔍 Vector Search	Semantic matching via Qdrant + OpenAI embeddings
🤖 AI Reranking	LLM-based result scoring for accuracy
✏️ Inline Editing	Modify quantities via Telegram buttons
📊 HTML Report	Professional expandable report with KPIs
📑 Excel Export	CSV with full work breakdown
📄 PDF Export	HTML-based PDF document
🌍 9 Languages	Full UI + database localization
💾 Session State	Multi-turn conversation support
🔧 Refine Mode	Re-analyze with additional context

Example Workflow

User: /start Bot: Language selection menu (9 options)

User: Selects 🇷🇺 Russian Bot: "Отправьте фото, PDF или текстовое описание работ"

User: Sends bathroom photo Bot: "📷 Анализ фото... ⏳"

Bot: Shows detected works:

🏠 Ванная комната — 4.5 m2

Найдено 12 работ:
1. Демонтаж плитки стен — 18 m2
2. Демонтаж плитки пола — 4.5 m2
3. Гидроизоляция пола — 4.5 m2
4. Гидроизоляция стен — 8 m2
5. Стяжка пола — 4.5 m2
6. Укладка плитки стены — 18 m2
7. Укладка плитки пол — 4.5 m2
8. Установка унитаза — 1 шт
9. Установка раковины — 1 шт
10. Установка смесителя — 2 шт
...

[✏️ Редактировать] [📊 Рассчитать]

User: Taps 📊 Calculate Bot: Shows progress per item, then final result:

✅ Смета готова — 12 позиций

💰 Итого: ₽ 89,450

Работа: ₽ 35,200 (39%)
Материалы: ₽ 48,750 (55%)
Механизмы: ₽ 5,500 (6%)

[📋 Детали] [↓ Excel] [↓ PDF] [↻ Заново]

HTML Report Features

• KPI Cards: Total cost, item count, labor days, cost breakdown %
• Expandable rows: Click work item to show resources
• Resource tags: Color-coded (Labor/Material/Machine)
• Scope of work: Expandable detailed descriptions
• Quality indicators: Match quality dots (high/medium/low)
• Responsive design: Works on mobile and desktop
• Export buttons: Expand/Collapse all

Notes & Tips

• Photo tips: Capture full room, include reference objects (doors, tiles)
• PDF support: Works best with clear floor plans and room schedules
• Text input: Supports lists, tables, free-form descriptions
• Rate accuracy: Depends on DDC CWICR coverage for your region
• Session timeout: User sessions persist across messages
• Extend: Chain with CRM, project management, or notification tools

Categories

AI · Communication · Data Extraction · Document Ops

Tags

telegram-bot, construction, cost-estimation, gpt-4-vision, gemini, pdf-analysis, qdrant, vector-search, multilingual, html-report

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Author

DataDrivenConstruction.io https://DataDrivenConstruction.io [email protected]

Consulting & Training

We help construction, engineering, and technology firms implement:

• AI-powered estimation systems (text, photo, PDF)
• Multi-channel bot integrations (Telegram, WhatsApp, Web)
• Vector database solutions for construction data
• Multilingual cost database deployment

Contact us to test with your data or adapt to your project requirements.

Resources

• DDC CWICR Database: GitHub
• Qdrant Documentation: qdrant.tech/documentation
• Gemini API: aistudio.google.com
• n8n Telegram Trigger: docs.n8n.io

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⭐ Star us on GitHub! github.com/datadrivenconstruction/DDC-CWICR