Kulma 21

In the heart of Helsinki, the Kulma21 building has recently undergone a major renovation. Originally opened in 1941, the building has housed various activities over the years, including the student council of Helsinki School of Business and offices.

During the recent renovation, special emphasis was placed on preserving and reviving the building’s historical appearance, taking into account the original design and architectural features from the time it was first built. Architects at Tengbom, the firm responsible for the renovation, say that part of renovating older buildings is to highlight the features that characterized buildings from those decades. Along with the renovation, the building was also updated to meet today’s demands in terms of technical and environmental aspects.

Renovating old buildings like Kulma21 can present complex challenges, especially when it comes to working with old building materials. In the last century, materials and construction methods were often used that did not meet modern requirements, for example regarding the safety of building materials, indoor air quality and so on. In fact, each decade has its own challenges, which are important to consider when undertaking such renovation projects and to be informed about possible dangers. For example, cork was used as insulation between brick or concrete walls in the 1950s, and asbestos and creosote were used until the 1960s and 1970s, and in some cases even longer. The biggest challenge in this case was the ceiling height, which does not correspond to the requirements for housing today. A multidisciplinary team of experts worked to solve the problem, which among other things included removing the subflooring, installing a centralized exhaust ventilation system, and the basement was lowered to accommodate services such as bicycle parking and a gym.

According to the architects who worked on the project, a history survey is one of the elements that is almost always part of successful renovation projects. The survey is a particularly important foundation when working with historically important buildings, such as buildings that have some form of protection by law, which was the case with Kulma21. Renovation projects also often require a zoning change in order to proceed, especially when the use of the building will change after renovation. In such cases, the authorities may require the results of such a survey with the request for a zoning change.

Kulma21 is an example of how renovation projects can have extensive environmental benefits, compared to building a new building. The carbon emissions of the renovation were 44% lower than if it were a new building. A life cycle analysis also shows that over a 50-year period, the cumulative carbon footprint of Kulma21 is 15% lower than if an equivalent new building had been built. As a result, the project is not only a successful cultural preservation project, but also has a significant environmental impact.