Specifications for independent home version 01-01-2025

The WWS points are calculated based on a set of rules for which specific inputs should be added. Before adding the inputs, the following information needs to be read in order to apply the correct input to the API and get the correct calculation of the WWS points.

1. Surface Area of Rooms

1.1 Requirements

In order for a room to be categorized as 'room' and not as 'other' (other space), it must meet the following requirements:

  • The floor must be passable.

  • The walls must be made of "solid" material.

  • The space must be at least 1.50 m wide over at least 80 percent of its length (the longest side).

  • The room must have a surface area of at least 4 m².

  • The space must cover at least 50% of the surface area or an area of 11 m² must have a free height of at least 2.10 m (measured from the floor to the visible ceiling).

  • The room must have at least 0.5 m² of transparent surface (window or door) adjacent to the outside air.

  • The room must have ventilation directly connected to the outside air.

  • There must be at least one power outlet and one light point.

Exception: A room that serves exclusively as a kitchen and a bathroom or shower room is always considered a room regardless of other requirements.

1.2 Measurement Standards

The surface area of rooms is measured from wall to wall, at a height of 1.50 meters above the floor, including the surface area of all loose and fixed cupboards belonging to the home. This measurement height also applies if the surface area deviates from that at floor level.

Included: Floor area under counters, appliances, bathtub, washbasin, toilet, shower tray, main fireplace, central heating boiler, boiler installation.

Not included: Area occupied by vertical alcoves, chimney ducts, ventilation ducts or stand or ground pipes.

Attic spaces: Only valued as rooms if accessible via a fixed staircase, floor is accessible, and roof is boarded.

1.3 Blocks & Features

Blocks: rooms, kitchen, sanitary, toilet Features: type_o_room, surface_area

2. Surface Area of Other Spaces

2.1 Requirements

In order for a room or area to be categorized as 'other' it must meet the following requirements:

  • The floor must be passable.

  • The room must have a surface area of at least 2 m².

  • The space does not meet the requirements for a 'room' or is not a traffic area (corridors, halls, landings).

2.2 Included Spaces

Other spaces include: utility rooms, storage rooms, laundry rooms, sheds, attics, and cellars. Private garages are valued as other space. Shared garages are valued under section 10.

2.3 Blocks & Features

Blocks: rooms, kitchen, sanitary, toilet Features: type_of_room, attic_without_fixed_staircase, surface_area

3. Heating & Cooling

3.1 Heating Requirements

For each heated room or other space, valuation points are applied if the heating is part of the immovable property and its appurtenances. Points are awarded as follows:

For 'room' type spaces:

  • Standard room/sanitary/toilet: 2 points

  • Kitchen (not open): 2 points

  • Kitchen (open): 4 points

For 'other' type spaces:

  • Standard room/sanitary/toilet: 1 point

  • Kitchen (not open): 1 point

  • Kitchen (open): 2 points

  • Cap: Maximum 4 points total for 'other' heating

3.2 Cooling Requirements

For cooled spaces, points are awarded if cooling facilities belong to the immovable property and meet these conditions:

  • Must also be able to heat (dual function required)

  • Valid NTA 8800 calculation must show "low" overheating risk

  • Central systems need underfloor cooling or low-temp radiators

  • Fixed AC units need A+ energy label + minimum 100W/m² at 35°C

Cooling Points:

  • Standard room (type 'room'): 1 point

  • Kitchen (type 'room', not open): 1 point

  • Kitchen (type 'room', open): 2 points

  • Other spaces get same points as rooms for cooling

  • Cap: Maximum 2 points total for cooling

3.3 Open Kitchen Definition

An open kitchen has an opening wider than 50% of the dividing wall, minimum 2m high over 0.85m width, non-closable. Both the kitchen and connected space get separate heating/cooling points.

3.4 Blocks & Features

Blocks: rooms, kitchen, sanitary, toilet Features: heated, cooled, open_kitchen (kitchen block only)

4. Energy Performance

4.1 Major Changes in 2025

IMPORTANT: The transitional rules for small dwellings (A.4.4) have EXPIRED as of 01/01/2025. No special point tables based on energy_valuation_date or usable_surface_area apply anymore.

4.2 Calculation Hierarchy

  1. Valid Energy Label: Use directly from updated 2025 point tables

  2. Energy Index exists: Use energy index with 2025 values

  3. Neither exists: Use building year with 2025 values

Updated 2025 Energy Label Points:

  • Eengezinswoning: A++++ (62 pts) down to G (-15 pts)

  • Meergezinswoning: A++++ (58 pts) down to G (-15 pts)

Updated 2025 Energy Index Points:

  • Similar ranges as before but with slight adjustments (e.g., 2.1-2.4 range now gives -5 instead of -4 points)

4.3 Monument Exception

If monument is 'national', 'municipal', or 'provincial' and energy points are negative, points are set to 0.

4.4 Energy Performance Compensation

If energy_performance_compensation is True:

  • Eengezinswoning: +32 points

  • Meergezinswoning: +28 points

4.5 Features

Features: energy_label, energy_index_existence, energy_index, build_year, house_type, monument, energy_performance_compensation

5. Kitchen

5.1 Countertop Length Points

  • < 1m: 0 points

  • 1m to < 2m: 4 points

  • ≥ 2m: 7 points

5.2 Kitchen Features (same as 2024)

Additional points for appliances and fixtures (extractor_system: 0.75, induction_hob: 1.75, etc.), capped at countertop length points.

5.3 Shared Address Division

NEW: Kitchen facility points are now divided by shared_addresses for multi-unit properties.

5.4 Blocks & Features

Blocks: kitchen Features: countertop_length, extractor_system, induction_hob, ceramic_hob, gas_hob, refrigerator, freezer, oven_electric, oven_gas, microwave, dishwasher, extra_cupboard_space_per_60cm, one_hand_mixer_tap, one_hand_mixer_tap_with_boiling_function, thermostatic_mixer_tap, thermostatic_mixer_tap_with_boiling_function

6. Sanitary Facilities

6.1 Toilet Points

  • Regular toilet: 2 points each

  • Wall-hung toilet: 2.75 points each (2 + 0.75 bonus)

6.2 Shower/Bath Facilities

  • Shower: 4 points

  • Bath: 6 points

  • Shower/bath combination: 7 points

6.3 Additional Features

Same feature points as 2024 (washbasin: 1, multi_person_washbasin: 1.5, etc.), capped by shower facility points.

6.4 Separate Toilets

Base 3 points + 0.75 for wall-hung + 1 for washbasin (max 1 per toilet room).

6.5 Blocks & Features

Blocks: sanitary, toilet Features: Various sanitary features including shower_facility, toilet counts, washbasin, etc.

7. Facilities for Disabled

7.1 Calculation

If disability_costs > 0 AND disabled_people > 0: Points = disability_costs ÷ 332 ÷ disabled_people

7.2 Features

Features: disability_costs, disabled_people

8. Private Outdoor Spaces

8.1 Calculation

No outdoor spaces: -5 points

With outdoor spaces:

  • Private (shared_addresses = 1): 2 + (0.35 × surface_area)

  • Communal: (0.75 × surface_area) ÷ shared_addresses

  • Cap: Maximum 15 points (positive values only)

8.2 Blocks & Features

Blocks: outdoor Features: surface_area

9. Common Indoor Spaces

No separate rule. Handled through shared_addresses division in Rules 1 & 2.

10. Communal Parking and Charging Stations

10.1 Parking Types

  • Type 1: 9 points ÷ shared_addresses + surface area tracked for WOZ

  • Type 2: 6 points ÷ shared_addresses

  • Type 3: 4 points ÷ shared_addresses

10.2 Charging Stations

If charging_station is True: 2 points ÷ shared_addresses

10.3 Blocks & Features

Blocks: parking Features: parking_type, surface_area, shared_addresses, charging_station

11. WOZ Value

11.1 Updated 2025 Parameters

Minimum WOZ: 77,582 (increased from 73,607)

Divisors for 2025:

  • 2024 WOZ reference: 15,329 (part 1), 242 standard / 103 special COROP (part 2)

  • 2023 WOZ reference: 14,543 (part 1), 229 standard / 97 special COROP (part 2)

11.2 Calculation Method

Basic WOZ Points = (woz_value ÷ divisor1) + ((woz_value ÷ total_surface_area) ÷ divisor2)

Total Surface Area = rooms + other_spaces + type1_parking_areas

11.3 Exception Rule (A.11.2)

If build_year 2015-2019 AND non-WOZ points ≥ 110 AND basic_woz_points < 40: Set basic_woz_points = 40

11.4 Cap Rule (A.11.3)

If total_points ≥ 187 AND not special COROP condition: If WOZ_points ÷ total_points > 0.33: Final_WOZ_points = non_WOZ_points × (0.33 ÷ 0.67), floored

11.5 186 Point Adjustment

If total > 186 but final < 187: Set total = 186

11.6 Features

Features: woz_value, woz_valuation_year, build_year, corop_area_amsterdam_or_utrecth

12. Special Provisions

12.1 Monument Status

IMPORTANT CHANGE: National monument bonus of 50 WWS points has been replaced by a 35% rent surcharge for new rental agreements. The 50-point system may still apply to existing contracts.

12.2 Care Home Surcharge

If care_home is True: +35% of total points from rules 1-11

Requirements:

  • Independent dwelling for physically disabled

  • Barrier-free access (≥1.2m corridors, lifts/ramps for ≥0.02m thresholds)

  • Emergency alarm system throughout building

  • Common areas for meals/recreation

12.3 Doorbell System

Video doorbell with remote door opening: +0.25 points

12.4 Features

Features: care_home, monument, doorbell

Key Changes from 2024 to 2025

  1. Energy Performance: Transitional rules expired, unified point tables

  2. WOZ Values: Updated minimum (77,582) and divisors

  3. Monument Points: 50-point monument bonus replaced by 35% rent surcharge

  4. Kitchen Division: Facility points now divided by shared_addresses

  5. Energy Points: Minor adjustments (e.g., 2.1-2.4 EI range: -4 → -5 points)

Total Points Calculation

Sum all component points from rules 1-12, applying caps where specified. If 186-point adjustment applies, final total = 186. Otherwise, sum all components and round to nearest whole number.

Maximum rent: €900.07 per month for independent homes in 2025 (at liberalization threshold).

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