We have created this Annex Project site to provide a central place for information and updates throughout the construction period. The site is being developed and will be updated as the project progresses and more information becomes available.

We will also publish maps showing the current traffic arrangements, access routes, and any changes affecting arrival at and departure from school. Following these arrangements helps us maintain a safe environment for students, families, staff, and visitors throughout the construction period.

Thank you for your patience and understanding during the Annex Project.

Latest News

Update 16.6.2026

As ISH offices wrap up and head into a well-deserved holiday this week, the school annex site is buzzing with energy! The quiet hallways allows UMR to safely take care of some of the heaviest and noisiest work over the break.

Here is a little look at what’s been happening behind the scenes and what’s coming up next:

What happened Past Week:

Outside: Heavy machinery has been at work, digging and prepping the ground for the new building's foundation and drainage systems.
Inside the Building: A protective wall was built in the lobby. This creates a completely isolated zone so the team can safely dismantle the old internal staircase without impacting the rest of the building. Extra helping hands have also arrived on site to finish up the safety walls on the upper floors.

In the Coming Weeks

The annex site will transition into its heaviest phase of construction. The official "piling" works will kick off to secure the foundations. Yard digging will continue, alongside some specialized diamond drilling on the ground floor to strengthen the base structures.

Once the heavy foundation work wraps up, bricklaying for a new staircase will begin.

Update 2.6.2026

Protective walls are being built inside the school to isolate the construction zones from our school and work areas.

This Week: We are kicking off interior and façade demolition, draining HVAC systems, and disconnecting electrical lines in the work zones. Outside, excavation in the yard continues, and the library wall and entrance canopy are being removed.
In the Coming Weeks: UMR will begin demolishing the interior staircase in the lobby while yard excavation continues. Heavy piling works will begin on-site, and all demolition phases are scheduled to be finalized.

The school offices continue to work for some more weeks, DP center and Main Campus are prepared for next school year, despite the significant construction site activities surrounding us.

Update 25.5.2026: report from UMR (construction company)

Last week, the site was officially established, and site office was set-up. Sewer and stormwater system connection work was carried out in the street area. On Thursday, we received the site fences at the property, and on Friday, we fenced off the construction site area.

Upcoming site activities for this last week of School:

Boarding and painting of the site fences, installation of the site gate.
Removal of paving stones and fences begins on Monday.
Removal of lighting poles.
Start of excavation works in the yard area on Wednesday.
Set up of the site sign.
Backfilling works in the street area and start of paving works on the street. Finalization / asphalt paving of the street area

Works in the first weeks of June:

Start of temporary site electrical works.
The arborist from the City of Helsinki will carry out branch thinning.
Set up of the site office continues.
Start of facade demolition works.
Construction of protective walls inside the school premises to separate the construction site from the school.
Start of interior demolition works. Start of demolition works for the interior staircase in the lobby. Demolition of the library wall and entrance canopy.
Excavation works in the yard continue.

Update 21.5.2026

As of today, the backyard has been cleared of cars and bikes, and entrance to the Main Building advised through main entrance at Selkämerenkatu, and side entrance at Messitytönkatu. Fencing started today with light fencing, closing the back entrance. Fencing work is expected to be completed latest early next week, with heavy fencing starting tomorrow.

Construction project launch meeting was held today, with participants including designers, constructors and project management, as well as ISH representatives.

A note about bikes: during the construction period, at least for now, we have no own bike racks in use. Instead, there are numerous fixed bike racks in the park adjacent to the school building and by the rocks. Our recommendation is to utilize those, taking into account that thieves do operate in the Ruoholahti area, and proper heavy duty locks are advised. Also, the School does not have surveillance access in this area, and therefore we cannot provide police assistance in case of any incidents.

Please see the map below for the location of the City of Helsinki bike racks.

Update 15.5.2026

As the Annex project progresses, updated access and traffic arrangements are planned from 21 May 2026. Please see the updated map below for student entrances, drop-off arrangements, and traffic guidance around the school area.

Following these arrangements helps us maintain a safe environment for students, families, staff, and visitors throughout the construction period. Thank you for your understanding during the Annex Project. Click the map to view the details.

Update 13.5.2026

Work at the corner of Messitytönkatu began this past Monday. Currently, a portion of the street has been excavated, but pedestrian access remains open around the work site. While this may cause some minor inconvenience, foot traffic continues to move safely and without disruption.

In preparation for the main phase of construction, we have achieved several key milestones:

Permits: The city has officially granted the necessary permits to begin work.
Safety: A fire consultant has reviewed and confirmed our temporary evacuation arrangements for the duration of the project.
Timeline: Planning for the main Annex construction site opening (behind Main Building) is on track for the end of next week.

Update 8.5.2026

Schedule Update: Messitytönkatu Corner

Work at the corner of Messitytönkatu was postponed this week due to a minor administrative delay in final permit approvals. We now expect work to commence on Monday, May 11th, or as soon as our contractor, UMR, receives the final go-ahead. Click the map to view the details

Environmental Management & Soil Cleaning

In accordance with standard city obligations, we are conducting soil cleaning. This process involves the careful handling, transportation, and sampling of soil. A formal notice regarding this work is being distributed to our neighboring buildings. The work poses no risk or danger to the environment, or people. This work will commence once digging work begins behind the school.

Update 30.4.2026

Below milestones have been updated to ensure the very latest information.

Annex Agreement Negotiations

Time and careful planning efforts have been put into ensuring our construction agreement is responsive to our needs to fully operate as a school during the period of construction (May 2026-September 2027).

The contract has been agreed upon in principle, allowing us to share the following preliminary milestones:

11.-21.5.2026, the corner of Messitytönkatu is opened to connect the annex to municipal infrastructure. Messitytönkatu street remains open for both cars and pedestrians, with one lane closed at a time. Heavy work is done before 9.00 to avoid disruptions to school work, particularly during IB exams. During this period, students can be dropped off by the Messitytönkatu park, and access school through backyard. Zebra crossing next to school (Messitytönkatu) will not be in use.
21.5.2026, fencing and digging work starts behind the school. Access to school happens through Messitytönkatu and Selkämerenkatu (front).
1.6.2026, heavy piling work commences. From this date until the end of July, there will be limited access to certain areas inside the main building.

We have been in touch with the city and the construction companies of the neighboring houses to request consideration to minimize heavy work during our IB exam period, from 27 April until 20 May.

Our Annex contract is based on a shared commitment to minimising disruption to normal school operations. It includes clear measures to limit disruption to school work, supported by ongoing communication. The construction schedule is aligned with the school year, with major works planned during the summer.

Additionally, over 1000m2 temporary space is rented to move part of the students off campus, and to allow more space in the main building to avoid spaces with a higher risk of noise. Despite all the preventative measures taken, it is important to note that a construction site will inherently cause more disruption than a standard school year.

Start of Annex Construction Site

Project officially kicks off on Monday, 18 May 2026. The period of May 18-30 is dedicated for site set-up and fencing. The School parking lot and back entrance will not be in use, and some clattering sounds may be heard from outside.

UMR is aware that IB exams are taking place until Wednesday, 20 May, and they are asked to be extra careful during those days. Noisy construction work will begin on 1 June, once school is on break.

Annex Decision and Construction Company Selection

The Extraordinary General Meeting voted to launch the Annex project on 11 March 2026. More information about the decision in Past Communications

Uudenmaan Mestari‑Rakentajat Oy (UMR) was selected as the main contractor by the Board of Governors.

Annex Project Town Hall

The Annex Town Hall took place on Tuesday, 24 February 2026 at 17.30 at ISH to introduce the project with an overview of the proposed design and its impact on teaching and learning. The meeting also covered the project timeline, financial planning, and risk management, and concluded with next steps and a Q&A session.

Town Hall materials can be found here.

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