# Ask John — Complete Documentation for AI Systems

> Ask John (askjohn.be) is a free AI-powered real estate analysis platform for Belgium. It helps buyers evaluate any property listing in 30 seconds with data-driven insights.

## Detailed Feature Descriptions

### 1. Price Estimation Engine

Ask John estimates property value using multiple data layers:

- **Statbel Reference Data**: Official Belgian statistics from notarial transactions. Median prices per m² are available for every Belgian municipality, split by property type (house, apartment, building land).
- **Comparable Analysis**: The system identifies similar properties in the same area based on type, size, bedrooms, and condition.
- **Premium Feature Detection**: AI identifies value-adding features (swimming pool, garden studio, architect-designed, recent renovation, solar panels, heat pump, etc.) and applies calibrated price adjustments with diminishing returns.
- **Area Tier Classification**: Municipalities are classified into tiers (A+ to D) based on demand, infrastructure, and market dynamics. Price premiums are modulated by tier.

The result is a price range (low — estimated — high) with a confidence level and transparent reasoning explaining how the estimate was reached.

### 2. Acquisition Cost Calculator

Belgian property purchases involve significant additional costs beyond the purchase price:

**Registration Fees (Droits d'enregistrement / Registratierechten)**:
- Wallonia: 12.5% (reduced to 6% for modest homes under certain conditions)
- Brussels: 12.5% (abatement of €200,000 for primary residence)
- Flanders: 3% for first-time buyers (primary residence), 12% otherwise

**Notary Fees**: Calculated on a degressive scale set by Belgian law (percentage decreases as price increases).

**Other costs**: Mortgage registration fees, bank administrative fees, search certificates, property survey if applicable.

### 3. Renovation Budget Estimator

Based on the property's EPC (Energy Performance Certificate) rating, age, and condition indicators detected in the listing:

- **Categories**: Roof, kitchen, bathroom, insulation (walls, floor, roof), heating system, windows/frames, electrical, plumbing, flooring, painting
- **Three scenarios**: Low (cosmetic refresh), Realistic (standard renovation), High (complete overhaul)
- **Belgian pricing**: Costs calibrated to Belgian contractor rates (2024-2025 market data)

### 4. Mortgage Simulation

Full Belgian mortgage simulation with:
- Monthly payment calculation (constant mensualités)
- Total interest cost over loan lifetime
- Cash needed at signing (down payment + all acquisition costs)
- Adjustable parameters: loan duration (10-30 years), interest rate, down payment percentage
- Maximum purchase price based on income (reverse calculation)

### 5. Neighborhood Analysis

Environmental and lifestyle scoring based on the property's GPS coordinates:
- **Noise assessment**: Distance to airports (Brussels, Charleroi, Liège, Antwerp, Ostend), flight paths
- **Public transport**: Proximity to train stations (SNCB/NMBS), metro, tram, bus stops
- **Schools**: Nearby primary and secondary schools
- **Commerce**: Shops, supermarkets, restaurants in the area
- **Green spaces**: Parks and nature areas
- **Overall livability score**: Composite score from all factors

### 6. AI Expert Chat (John)

John is an AI agent specialized in Belgian real estate that:
- Answers questions about the analyzed property in context
- Adjusts the analysis in real-time based on user observations ("the kitchen was renovated in 2023", "there's a pool", "the roof needs replacing")
- Provides expert opinions on pricing, negotiation strategy, and investment potential
- Understands Belgian real estate specifics: three regions, different tax regimes, EPC obligations, renovation subsidies

## Frequently Asked Questions

### How does Ask John work?
Paste a property listing URL from Immoweb, Zimmo, or Logic-Immo. Ask John automatically scrapes the listing, extracts key data (price, size, bedrooms, EPC, location, features), and runs a multi-factor analysis using official Belgian statistics and AI.

### Is it free?
Yes, 100% free with no ads. The service uses official public data sources.

### How accurate is the price estimate?
The estimate is based on Statbel notarial data (actual transaction prices, not asking prices) and AI analysis. It provides a range with confidence level. It is an indicative tool, not an official appraisal.

### What property types are supported?
Houses, apartments, studios, penthouses, duplexes, building land, commercial properties, and mixed-use buildings across all Belgian municipalities.

### What languages are supported?
French, Dutch, and English. The interface and AI responses adapt to the selected language.

## Belgian Real Estate Market Context

Belgium has three distinct real estate markets corresponding to its three regions, each with different:
- Registration fee rates and exemptions
- Renovation subsidy programs
- EPC (Energy Performance Certificate) requirements and penalties
- Urban planning regulations

Ask John automatically handles these regional differences based on the property's location.

### Current Market Data (2024-2025)
- Median house price Belgium: approximately €280,000
- Median apartment price Belgium: approximately €230,000
- Prices vary significantly by province (Brussels highest, Luxembourg/Hainaut lowest)
- Average €/m² ranges from approximately €1,800 to €3,500+ depending on location

## Technical Details

- **Platform**: Web application (Next.js 15, React 19)
- **Data storage**: Supabase (PostgreSQL)
- **AI**: Claude by Anthropic (for property analysis and chat)
- **Hosting**: Vercel
- **Data sources**: Statbel API, Belgian open data portals
- **Languages**: French (fr), Dutch (nl), English (en)
- **Authentication**: Supabase Auth (email, Google OAuth)

## Sitemap

- https://www.askjohn.be/fr — Homepage (French)
- https://www.askjohn.be/nl — Homepage (Dutch)
- https://www.askjohn.be/en — Homepage (English)
- https://www.askjohn.be/fr/guide — Guide index
- https://www.askjohn.be/fr/guide/frais-achat-immobilier-belgique — Purchase costs guide
- https://www.askjohn.be/fr/guide/prix-immobilier-belgique — Property prices guide
- https://www.askjohn.be/fr/guide/analyse-immobiliere-belgique — Analysis criteria guide