RAG Construction
Overview
Based on DDC methodology (Chapter 2.3), this skill builds Retrieval-Augmented Generation (RAG) systems for construction knowledge bases, enabling semantic search and AI-powered question answering over construction documents.
Book Reference: "Pandas DataFrame и LLM ChatGPT" / "Pandas DataFrame and LLM ChatGPT"
Quick Start
from dataclasses import dataclass, field
from enum import Enum
from typing import List, Dict, Optional, Any, Callable
from datetime import datetime
import json
import hashlib
import re
class DocumentType(Enum):
"""Types of construction documents"""
SPECIFICATION = "specification"
DRAWING = "drawing"
CONTRACT = "contract"
RFI = "rfi"
SUBMITTAL = "submittal"
CHANGE_ORDER = "change_order"
MEETING_MINUTES = "meeting_minutes"
DAILY_REPORT = "daily_report"
SAFETY_REPORT = "safety_report"
INSPECTION = "inspection"
MANUAL = "manual"
STANDARD = "standard"
class ChunkingStrategy(Enum):
"""Text chunking strategies"""
FIXED_SIZE = "fixed_size"
PARAGRAPH = "paragraph"
SECTION = "section"
SEMANTIC = "semantic"
SENTENCE = "sentence"
@dataclass
class DocumentChunk:
"""A chunk of document text"""
id: str
document_id: str
content: str
metadata: Dict[str, Any]
embedding: Optional[List[float]] = None
token_count: int = 0
position: int = 0
@dataclass
class Document:
"""Construction document"""
id: str
title: str
doc_type: DocumentType
content: str
source: str
metadata: Dict[str, Any] = field(default_factory=dict)
chunks: List[DocumentChunk] = field(default_factory=list)
created_at: datetime = field(default_factory=datetime.now)
@dataclass
class SearchResult:
"""Search result from vector store"""
chunk: DocumentChunk
score: float
document_title: str
doc_type: DocumentType
@dataclass
class RAGResponse:
"""Response from RAG system"""
query: str
answer: str
sources: List[SearchResult]
confidence: float
tokens_used: int
class TextChunker:
"""Split documents into chunks for embedding"""
def __init__(
self,
strategy: ChunkingStrategy = ChunkingStrategy.PARAGRAPH,
chunk_size: int = 500,
chunk_overlap: int = 50
):
self.strategy = strategy
self.chunk_size = chunk_size
self.chunk_overlap = chunk_overlap
def chunk_document(self, document: Document) -> List[DocumentChunk]:
"""Split document into chunks"""
if self.strategy == ChunkingStrategy.FIXED_SIZE:
return self._chunk_fixed_size(document)
elif self.strategy == ChunkingStrategy.PARAGRAPH:
return self._chunk_by_paragraph(document)
elif self.strategy == ChunkingStrategy.SECTION:
return self._chunk_by_section(document)
elif self.strategy == ChunkingStrategy.SENTENCE:
return self._chunk_by_sentence(document)
else:
return self._chunk_fixed_size(document)
def _chunk_fixed_size(self, document: Document) -> List[DocumentChunk]:
"""Chunk by fixed character size with overlap"""
chunks = []
text = document.content
start = 0
position = 0
while start < len(text):
end = start + self.chunk_size
# Find word boundary
if end < len(text):
while end > start and text[end] not in ' \n\t':
end -= 1
chunk_text = text[start:end].strip()
if chunk_text:
chunk_id = self._generate_chunk_id(document.id, position)
chunks.append(DocumentChunk(
id=chunk_id,
document_id=document.id,
content=chunk_text,
metadata={
"doc_type": document.doc_type.value,
"title": document.title,
**document.metadata
},
token_count=len(chunk_text.split()),
position=position
))
position += 1
start = end - self.chunk_overlap
if start >= len(text):
break
return chunks
def _chunk_by_paragraph(self, document: Document) -> List[DocumentChunk]:
"""Chunk by paragraphs"""
chunks = []
paragraphs = document.content.split('\n\n')
current_chunk = ""
position = 0
for para in paragraphs:
para = para.strip()
if not para:
continue
if len(current_chunk) + len(para) < self.chunk_size:
current_chunk += "\n\n" + para if current_chunk else para
else:
if current_chunk:
chunk_id = self._generate_chunk_id(document.id, position)
chunks.append(DocumentChunk(
id=chunk_id,
document_id=document.id,
content=current_chunk,
metadata={
"doc_type": document.doc_type.value,
"title": document.title,
**document.metadata
},
token_count=len(current_chunk.split()),
position=position
))
position += 1
current_chunk = para
# Add remaining content
if current_chunk:
chunk_id = self._generate_chunk_id(document.id, position)
chunks.append(DocumentChunk(
id=chunk_id,
document_id=document.id,
content=current_chunk,
metadata={
"doc_type": document.doc_type.value,
"title": document.title,
**document.metadata
},
token_count=len(current_chunk.split()),
position=position
))
return chunks
def _chunk_by_section(self, document: Document) -> List[DocumentChunk]:
"""Chunk by document sections (headers)"""
# Split by common section patterns
section_pattern = r'\n(?=(?:\d+\.|\d+\s|SECTION|ARTICLE|PART)\s+[A-Z])'
sections = re.split(section_pattern, document.content)
chunks = []
for position, section in enumerate(sections):
section = section.strip()
if section:
# If section is too large, further split it
if len(section) > self.chunk_size * 2:
sub_chunker = TextChunker(ChunkingStrategy.PARAGRAPH, self.chunk_size)
sub_doc = Document(
id=f"{document.id}_sec{position}",
title=document.title,
doc_type=document.doc_type,
content=section,
source=document.source,
metadata=document.metadata
)
sub_chunks = sub_chunker.chunk_document(sub_doc)
for i, chunk in enumerate(sub_chunks):
chunk.id = self._generate_chunk_id(document.id, position * 100 + i)
chunk.position = position * 100 + i
chunks.extend(sub_chunks)
else:
chunk_id = self._generate_chunk_id(document.id, position)
chunks.append(DocumentChunk(
id=chunk_id,
document_id=document.id,
content=section,
metadata={
"doc_type": document.doc_type.value,
"title": document.title,
**document.metadata
},
token_count=len(section.split()),
position=position
))
return chunks
def _chunk_by_sentence(self, document: Document) -> List[DocumentChunk]:
"""Chunk by sentences, grouping to meet size requirements"""
# Simple sentence splitting
sentences = re.split(r'(?<=[.!?])\s+', document.content)
chunks = []
current_chunk = ""
position = 0
for sentence in sentences:
if len(current_chunk) + len(sentence) < self.chunk_size:
current_chunk += " " + sentence if current_chunk else sentence
else:
if current_chunk:
chunk_id = self._generate_chunk_id(document.id, position)
chunks.append(DocumentChunk(
id=chunk_id,
document_id=document.id,
content=current_chunk.strip(),
metadata={
"doc_type": document.doc_type.value,
"title": document.title,
**document.metadata
},
token_count=len(current_chunk.split()),
position=position
))
position += 1
current_chunk = sentence
if current_chunk:
chunk_id = self._generate_chunk_id(document.id, position)
chunks.append(DocumentChunk(
id=chunk_id,
document_id=document.id,
content=current_chunk.strip(),
metadata={
"doc_type": document.doc_type.value,
"title": document.title,
**document.metadata
},
token_count=len(current_chunk.split()),
position=position
))
return chunks
def _generate_chunk_id(self, doc_id: str, position: int) -> str:
"""Generate unique chunk ID"""
return hashlib.md5(f"{doc_id}_{position}".encode()).hexdigest()[:12]
class VectorStore:
"""Simple in-memory vector store for RAG"""
def __init__(self):
self.chunks: Dict[str, DocumentChunk] = {}
self.embeddings: Dict[str, List[float]] = {}
def add_chunks(self, chunks: List[DocumentChunk]):
"""Add chunks to the store"""
for chunk in chunks:
self.chunks[chunk.id] = chunk
if chunk.embedding:
self.embeddings[chunk.id] = chunk.embedding
def search(
self,
query_embedding: List[float],
top_k: int = 5,
filter_metadata: Optional[Dict] = None
) -> List[Tuple[DocumentChunk, float]]:
"""Search for similar chunks"""
results = []
for chunk_id, chunk in self.chunks.items():
# Apply metadata filter
if filter_metadata:
match = all(
chunk.metadata.get(k) == v
for k, v in filter_metadata.items()
)
if not match:
continue
# Calculate similarity (cosine similarity simulation)
if chunk_id in self.embeddings:
score = self._cosine_similarity(query_embedding, self.embeddings[chunk_id])
results.append((chunk, score))
# Sort by score descending
results.sort(key=lambda x: x[1], reverse=True)
return results[:top_k]
def _cosine_similarity(self, a: List[float], b: List[float]) -> float:
"""Calculate cosine similarity between two vectors"""
if len(a) != len(b):
return 0.0
dot_product = sum(x * y for x, y in zip(a, b))
norm_a = sum(x * x for x in a) ** 0.5
norm_b = sum(x * x for x in b) ** 0.5
if norm_a == 0 or norm_b == 0:
return 0.0
return dot_product / (norm_a * norm_b)
def get_stats(self) -> Dict:
"""Get store statistics"""
doc_types = {}
for chunk in self.chunks.values():
doc_type = chunk.metadata.get("doc_type", "unknown")
doc_types[doc_type] = doc_types.get(doc_type, 0) + 1
return {
"total_chunks": len(self.chunks),
"chunks_with_embeddings": len(self.embeddings),
"chunks_by_type": doc_types
}
class EmbeddingModel:
"""Simulated embedding model (replace with actual model in production)"""
def __init__(self, model_name: str = "text-embedding-ada-002"):
self.model_name = model_name
self.dimension = 1536
def embed(self, text: str) -> List[float]:
"""Generate embedding for text"""
# Simulation: generate deterministic embedding based on text hash
text_hash = hashlib.sha256(text.encode()).digest()
embedding = []
for i in range(self.dimension):
byte_idx = i % len(text_hash)
embedding.append((text_hash[byte_idx] - 128) / 128.0)
return embedding
def embed_batch(self, texts: List[str]) -> List[List[float]]:
"""Generate embeddings for multiple texts"""
return [self.embed(text) for text in texts]
class ConstructionRAG:
"""
RAG system for construction knowledge bases.
Based on DDC methodology Chapter 2.3.
"""
def __init__(
self,
embedding_model: Optional[EmbeddingModel] = None,
chunking_strategy: ChunkingStrategy = ChunkingStrategy.PARAGRAPH,
chunk_size: int = 500
):
self.embedding_model = embedding_model or EmbeddingModel()
self.chunker = TextChunker(chunking_strategy, chunk_size)
self.vector_store = VectorStore()
self.documents: Dict[str, Document] = {}
def add_document(self, document: Document) -> int:
"""
Add a document to the knowledge base.
Args:
document: Document to add
Returns:
Number of chunks created
"""
# Store document
self.documents[document.id] = document
# Chunk document
chunks = self.chunker.chunk_document(document)
# Generate embeddings
for chunk in chunks:
chunk.embedding = self.embedding_model.embed(chunk.content)
# Add to vector store
self.vector_store.add_chunks(chunks)
# Update document with chunks
document.chunks = chunks
return len(chunks)
def add_documents(self, documents: List[Document]) -> Dict[str, int]:
"""Add multiple documents"""
results = {}
for doc in documents:
results[doc.id] = self.add_document(doc)
return results
def search(
self,
query: str,
top_k: int = 5,
doc_type: Optional[DocumentType] = None
) -> List[SearchResult]:
"""
Search the knowledge base.
Args:
query: Search query
top_k: Number of results to return
doc_type: Filter by document type
Returns:
List of search results
"""
# Generate query embedding
query_embedding = self.embedding_model.embed(query)
# Build filter
filter_metadata = None
if doc_type:
filter_metadata = {"doc_type": doc_type.value}
# Search vector store
results = self.vector_store.search(
query_embedding,
top_k=top_k,
filter_metadata=filter_metadata
)
# Build search results
search_results = []
for chunk, score in results:
doc = self.documents.get(chunk.document_id)
search_results.append(SearchResult(
chunk=chunk,
score=score,
document_title=doc.title if doc else "Unknown",
doc_type=doc.doc_type if doc else DocumentType.MANUAL
))
return search_results
def query(
self,
question: str,
top_k: int = 5,
doc_type: Optional[DocumentType] = None
) -> RAGResponse:
"""
Answer a question using RAG.
Args:
question: Question to answer
top_k: Number of context chunks to use
doc_type: Filter by document type
Returns:
RAG response with answer and sources
"""
# Search for relevant context
search_results = self.search(question, top_k=top_k, doc_type=doc_type)
if not search_results:
return RAGResponse(
query=question,
answer="I couldn't find relevant information to answer this question.",
sources=[],
confidence=0.0,
tokens_used=0
)
# Build context from search results
context_parts = []
for i, result in enumerate(search_results):
context_parts.append(
f"[Source {i+1}: {result.document_title}]\n{result.chunk.content}"
)
context = "\n\n".join(context_parts)
# Generate answer (simulated - in production, call LLM)
answer = self._generate_answer(question, context, search_results)
# Calculate confidence
avg_score = sum(r.score for r in search_results) / len(search_results)
return RAGResponse(
query=question,
answer=answer,
sources=search_results,
confidence=avg_score,
tokens_used=len(context.split()) + len(question.split())
)
def _generate_answer(
self,
question: str,
context: str,
sources: List[SearchResult]
) -> str:
"""
Generate answer from context.
In production, this would call an LLM API.
"""
# Simulated answer generation
answer_parts = [
f"Based on the available construction documentation:\n"
]
# Extract key information from sources
for source in sources[:3]:
# Take first sentence of each relevant chunk
first_sentence = source.chunk.content.split('.')[0] + '.'
answer_parts.append(f"- {first_sentence}")
answer_parts.append(
f"\n\nThis information comes from {len(sources)} source documents "
f"including: {', '.join(set(s.document_title for s in sources[:3]))}."
)
return "\n".join(answer_parts)
def get_document_summary(self, document_id: str) -> Optional[Dict]:
"""Get summary of a document"""
doc = self.documents.get(document_id)
if not doc:
return None
return {
"id": doc.id,
"title": doc.title,
"type": doc.doc_type.value,
"chunks": len(doc.chunks),
"total_tokens": sum(c.token_count for c in doc.chunks),
"source": doc.source,
"created_at": doc.created_at.isoformat()
}
def get_stats(self) -> Dict:
"""Get system statistics"""
return {
"total_documents": len(self.documents),
"vector_store": self.vector_store.get_stats(),
"embedding_model": self.embedding_model.model_name,
"chunking_strategy": self.chunker.strategy.value
}
def export_knowledge_base(self) -> Dict:
"""Export knowledge base for backup/transfer"""
return {
"documents": [
{
"id": doc.id,
"title": doc.title,
"type": doc.doc_type.value,
"content": doc.content,
"source": doc.source,
"metadata": doc.metadata
}
for doc in self.documents.values()
],
"stats": self.get_stats(),
"exported_at": datetime.now().isoformat()
}Common Use Cases
Build Construction Knowledge Base
rag = ConstructionRAG(
chunking_strategy=ChunkingStrategy.SECTION,
chunk_size=500
)
# Add specifications
spec_doc = Document(
id="spec-03300",
title="Cast-in-Place Concrete Specification",
doc_type=DocumentType.SPECIFICATION,
content="""
SECTION 03 30 00 - CAST-IN-PLACE CONCRETE
PART 1 - GENERAL
1.1 SUMMARY
A. Section includes cast-in-place concrete for foundations,
slabs, walls, and other structural elements.
1.2 RELATED SECTIONS
A. Section 03 10 00 - Concrete Forming
B. Section 03 20 00 - Concrete Reinforcing
PART 2 - PRODUCTS
2.1 CONCRETE MATERIALS
A. Portland Cement: ASTM C150, Type I or II
B. Aggregates: ASTM C33, graded
C. Water: Clean, potable
""",
source="project_specs.pdf",
metadata={"division": "03", "project": "Building A"}
)
chunks_created = rag.add_document(spec_doc)
print(f"Created {chunks_created} chunks")Search Knowledge Base
# Search for concrete requirements
results = rag.search(
query="concrete strength requirements",
top_k=5,
doc_type=DocumentType.SPECIFICATION
)
for result in results:
print(f"Score: {result.score:.3f}")
print(f"Document: {result.document_title}")
print(f"Content: {result.chunk.content[:200]}...")
print()Answer Questions with RAG
response = rag.query(
question="What type of cement should be used for foundations?",
top_k=3
)
print(f"Answer: {response.answer}")
print(f"Confidence: {response.confidence:.0%}")
print(f"Sources: {len(response.sources)}")Quick Reference
| Component | Purpose |
|---|---|
ConstructionRAG | Main RAG system |
TextChunker | Document chunking |
VectorStore | Embedding storage |
EmbeddingModel | Text embeddings |
DocumentChunk | Chunk with metadata |
RAGResponse | Query response |
Resources
- Book: "Data-Driven Construction" by Artem Boiko, Chapter 2.3
- Website: https://datadrivenconstruction.io
Next Steps
- Use llm-data-automation for automation
- Use vector-search for advanced search
- Use document-classification-nlp for classification