Geothermal heating

Geothermal wells cannot be placed in the vicinity of underground spaces, structures, space allocations, or stands of valuable timber trees.  They also can’t be built in a groundwater area, nature reserve or a historical site. Order a report on the feasibility of well construction or order a preliminary negotiation to determine whether there is a factor that could prevent the well’s construction.

Just one or two geothermal heat wells are usually installed on plots with detached houses. Mark the planned locations of the geothermal wells on a map drawing and order a report on construction feasibility. The map drawing must clearly show the property and its borders.A base map can be found in the Helsinki Map Service.(Link leads to external service)

Plots containing blocks of flats may need more geothermal wells. Start by ordering a preliminary negotiation to determine whether a geothermal project is a feasible option for the plot. After this has been done, you can order a more detailed geothermal plan from a professional.

The processing time of preliminary enquiries and feasibility studies is normally one week or, in the case of demanding sites, three weeks.

Order a preliminary negotiation or a report on construction feasibility (in Finnish)(Link leads to external service)

If geothermal energy appears to be feasible, hire a company with the necessary expertise to map out the implementation in more detail. 

Professionals should be responsible for the design and construction. They can also fill in the permit application and collect the required attachments. 

As the builder or person commissioning the construction project, you are responsible for obtaining the neighbours’ consent (section 3) and amending the geothermal terms of the lease agreement (section 4) in projects in which these tasks are necessary.

You  must obtain your neighbour's consent for the construction of a geothermal heat well if the well to be constructed on your own property is located within 7.5 metres (measured from the mean depth of the well) of the border of the neighbour’s property or the centre line of the street area. If the geothermal heat well is slanted towards your property, the minimum distance of the starting point of the well from the neighbour’s border without the neighbor's consent is 2.5 metres.

The neighbours’ consent must be given in writing, and you are responsible for arranging it.
If the owner of your neighbouring property is the City of Helsinki, you must obtain consent from the city.

If the neighbour is a rented plot of the city, the party renting the plot must be heard. The hearing and the consent of the neighbour are two different things, even though the city’s standard form model includes them both.

Read more and request a hearing or consent of a neighbour

If you are building on a rented plot owned by the City of Helsinki, and your lease agreement does not allow the construction of a geothermal heat well, you must ask for the consent of the landowner. Geothermal heat wells can be agreed on when preparing the new lease agreements, which means that no consent needs to be asked separately.

Apply to add a geothermal clause to your plot lease agreement

The drilling of a geothermal heat well creates rough rock material and sludge that cannot be led directly to a waterway, sea, ditch, street or stormwater or waste water sewer. Drilling waste must be managed so that it does not harm the environment, neighbours or sewage system. No such drilling water that is of poorer quality than natural water can be dumped in a waterway.

When the permit for the well is applied for, a plan for the management of drilling water must be attached. 

Management instruction for the drilling water of a geothermal heat well (In Finnish, pdf, 2 MB).

The construction of a geothermal heat well requires a planning permission for minor construction. If you are planning a new building and want to drill a geothermal heat well as part of its construction, you can apply for a permission for the geothermal heat well within the same building permit.

The main designer takes care of filling in the permit application and the collection of the related documents.

Appendices of a permit application:

• Report on the right of possession i.e. a certificate showing that the applicant owns the plot or that the applicant has the owner’s permission for the construction
• Extract from the trade register, if the applicant is a company
• Letter of authorisation, if the application is signed by a representative and not the applicant
• Feasibility study on geothermal heat 
• Layout plan made by the main designer
• Report on the management of drilling waste
• Neighbour’s consent, if necessary
• Lease with a geothermal clause (applies to a plot leased from the city, see section 4. Apply to add a geothermal clause to your plot lease agreement)
• If necessary, an energy sufficiency calculation or modelling.  Energy wells should be sized so that the temperature loss at the boundary with the neighbour and the centre line of the street area is not more than 2 ^oC. An energy sufficiency calculation or modelling may be required on a case-by-case basis.

If the geothermal well is located in a public area, please attach the following annexes to the permit application in addition to the above: 

• Placement plan. See instructions in the publication Geothermal wells in public areas in Helsinki, section 7.6 (In Finnish, pdf, 7 MB).
• Restoration plan, if starting points are in a public area. See instructions in the publication Geothermal wells in public areas in Helsinki, section 7.7 (In Finnish, pdf, 7 MB).
• Placement agreement.
• Public area land lease, if 10 or more starting points are in a public area. 

Read more and apply for a planning permission for minor construction

Once you have obtained a legally valid planning permission for minor construction or building permit, you can commence the construction of the geothermal heat well. Be sure to review the permission or permit decision thoroughly.

Remember to notify Environmental Services of the exact start date of the drilling at least three business days before the start date.

Submit the notification via email to kymp.maaperavalvonta@hel.fi(Link opens default mail program).  The email message must include the site’s address and Lupapiste identifier and the exact start date of the drilling.

The notification must also include a plan that clearly details the management of the site’s drilling water: the size and number of sedimentation containers or other processing arrangements and where the processed water will be discharged or possibly absorbed.

Order an inspection of the location once the drilling commences(section 8). 

Once the construction work is complete, the city survey services will survey the starting points of drilling before the wells are covered and the services will check that the wells were drilled in accordance with the permits. The location inspection requires a drilling report prepared by the driller (professional) which presents things such as the depth and inclination of the wells.

Order an inspection of the location

A geothermal heat system can be placed, either partially or entirely, in a public area such as a park or street area. When ordering a report of the feasibility of construction, you must justify why placing a geothermal heat system in a public area is necessary. Deliver a preliminary project plan, too. Decisions are made case by case.

The permit application of a geothermal heat well to be built in a public area must also include a placement or lease agreement and a restoration plan. During the construction phase, make a formal notification to the City of a work to be performed in a public area. 

Principally, geothermal heat systems are placed on your own plot, at least 7.5 metres away from the border you share with a neighbour or the centre line of the neighbouring street area. If adequate energy cover cannot be achieved, geothermal heat wells can be placed less than 7.5 metres away from the border of a public area/centre line of a street area. The geothermal heat wells can also be tilted so they reach the side of the public area. A geothermal heat well field or part of a such field can be placed in a public area.

You can find more information and theoretical examples in the following publications:

• Geothermal wells in public areas in Helsinki 2021:20 pages 39–51 (PDF, in Finnish, 7.0 MB)
• Building-, block- and area-specific geothermal solutions in Helsinki 2022:24, pages 14–30 (PDF, in Finnish, 4.4 MB)
• Placing geothermal systems in green space - practices and impacts, Urban Environment Division Publications 2023:23 (pdf, 19 Mt)

You will need a placement agreement with the city if geothermal wells are to be built or placed in a public area. The feasibility study will provide you with information on how to conclude a placement agreement and whether  you also need a lease agreement with the city.

Make a placement and lease agreement before applying for a building permit or planning permission. Attach the approved agreement to the permit application.

Obtain the apply for a placement agreement in Lupapiste.

If you need a lease agreement in a public area, please contact: tonttivalvonta@hel.fi(Link opens default mail program)

For more information on installing geothermal heat in a public area kymp.maalampo@hel.fi(Link opens default mail program).

The main designer makes the restoration plan to be attached to the application for a building permit or planning permission for minor construction. The plan details how the environment of the site will be restored (once the geothermal heat system has been completed) as accurately as possible to the state it was in before the construction. Restoration must take into consideration things such as repairing and reworking the ground, vegetation and surface structures.

Read the instruction: Use of public areas, temporary arrangements, and street repairs (In Finnish, pdf, 2 MB).

Once you have received a legally valid building permit or planning permission for minor construction, you can start the construction work for the geothermal heat well.

Notify the city of the work to be performed in a public area at least 7 days before the start of the work. If the work affects traffic, submit a traffic management plan with the excavation notification.

Read the instructions for work to be performed in a public area.