Matter of Fact: How a city is planned

The detailed plan defines what kinds of buildings can be built in the different areas of the city. Let us see what happened in Sompasaari, Kalasatama, before new Heka homes could be built in the area.

Written by Petja Partanen Photos by Essi Kuula

1. Beginning

An initiative for the preparation of a plan can be made by the land owner or various actors in the city. In addition to new areas, old areas are also constantly being planned further.

At first, an outline is produced on how the planning project will proceed. This is called a participation and assessment plan. It includes the goals and premises of the planning work, how the preparation of the plan will proceed and how people can participate in the preparation.

You can find information about new planning projects online at and in the annual planning review.

A picture of a line. It is used to separate Sompasaari-sections of the article from rest of the text. The same picture is used many times in the article, and from now on it will have alternative text "Separation line" with it.

Creating Sompasaari:

In 2008, the Sörnäinen container harbour moved to Vuosaari, and the entire Kalasatama area was freed up for construction. The old buildings in Sompasaari were demolished so that the detailed plan for the area could be prepared from scratch.

The participation and assessment plan for Sompasaari was finished in August 2013.

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2. Plan proposal

A plan proposal for decision-making is prepared on the basis of the preparatory materials, taking into consideration the opinions submitted earlier as far as possible.

The easiest way to follow the progress of and plans for the various areas in Helsinki is via the map service

If a resident is unhappy with the plan proposal, they can submit a written objection to it.

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Creating Sompasaari:

The first draft plans for new Sompasaari were on display at a public event in August 2013.

In January 2014, the planners had revised the proposal based on the feedback received, and the proposal for the detailed plan of Sompasaari was put on public display.

This is what the virtual photo based on the new detailed plan looked like for the Sompasaari area of 3,000 residents.

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Piirroskuvassa on tietokone, jonka ruudulla on Sompasaaren kaavoituskuva.

3. Approval

The planners who prepared the plan respond to the statements and objections and revise the plan as necessary.

The detailed plan document defines the plot locations, the maximum areas permitted for the buildings and the floor heights. In addition to these, the detailed plan usually includes instructions regarding the appearance of the buildings and any parking spaces.

Anyone dissatisfied with a decision to approve a plan can appeal against the decision to Helsinki Administrative Court.

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Creating Sompasaari:

The detailed plan for Sompasaari moved to the City Council’s approval processing in August 2014.

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A drawn picture of a computer with a man shown in the screen. There are speech bubles around the computer with texts "More trees" and "Will there be bikelines".

4. The plan comes into effect

If the decision to approve a plan is not appealed against, the detailed plan will take effect after the end of the appeal period through a notice published on the City’s website.

If a plan is appealed against, the plan will come into effect if the appeal is rejected. In this case, the detailed plan will come into effect through a public notice given only after the court proceedings

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Creating Sompasaari:

In October 2014, the detailed plan for Sompasaari entered into legal force and the construction of the streets and municipal engineering systems began. The first residents moved to Sompasaari in 2018. The first Heka tenants of Sompasaari moved to Kapteeni Sundmanin katu in 2019.

In spring 2021, the second Heka housing location in Sompasaari received its building permit. The homes on Kaljaasi Fortunan katu will be completed in late 2023.

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Make a difference

All Helsinki residents can participate in the planning. In the different stages of the planning, you can review the project and express your opinions by letter or email, by participating in events or online discussions, or by contacting the planner directly. 

Read more about the planning process.


A drawn picture with an information about how many new apartments there will be build in Helsinki. The goal is to have 7,000 new appartments annually, which reguires 700,000 floor square meters reserved for housing every year.