Table 4.

Definition of explanatory variables in the time-dummy hedonic model

Source: Extract from NVM data

Characteristics	Description	Variable type	Measurement unit
M2	Total usable floor area in square metres	Continuous	Positive real number
NKAMERS	Number of rooms	Continuous	Positive integer
NVERDIEP	Number of floors	Continuous	Positive integer
AGE	The age of the building in decades	Continuous	Non-negative integer
VERW	System of heating	Categorical	$0,\dots ,3$
ONBI	Maintenance level inside the property	Categorical	$1,\dots ,9$
HOUSETYPE	Type of house	Categorical	$2,\dots ,7$
LOC	The district in which property is located	Categorical	$0,\dots ,14$

Type of heating system: no heating system, gas/stove heating, central boiler heating and air condition/solar heating. Maintenance level: bad, poor to moderate, moderate, moderate to reasonable, reasonable, reasonable to good, good, good to excellent and excellent. Properties classes: terraced house, town house, corner house, semi-detached house, detached house and apartment. The location of the properties was categorised into 15 as specified in Table 1