Addresses are given based on the street and road names confirmed in the city plan. Address numbers are assigned so that the left-hand side (from the start of the road) of the road has even numbers and the right-hand side has odd numbers. In semi-urban areas, the numbers are assigned based on the distance to the property, counted from the start of the road: the address number is based on the distance in metres with the last digit removed.
In an area under the city plan, a property is assigned an address number upon the property formation. Buildings are assigned an address during the application for a building permit.
Changes to the city plan and changing road arrangements in semi-urban areas can cause address and street name changes. The changed addresses and street names are put to use according to the progress of the city plan implementation or when the new road arrangements are put to use. Property owners are notified of address changes before the changes are implemented.
Communication regarding addresses
The City will report the address information to the Finnish Population Information System. From there, the information is conveyed to different operators. Address changes are also reported to the rescue department, Posti's address service, Lahti Energia and Lahti Aqua.
The owner of a property must acquire and install address number plates for the property. In the city plan area, the street name plates and signs are acquired and installed by the City. In semi-urban areas, road name plates and signs are acquired and installed by road maintenance associations.