Planning of Hämeentie renovation - Case Hämeentie, City of Helsinki
City of Helsinki, Urban Environment Division
Object of procurement
Hämeentie street and construction planning: €371,000
Emission calculation and climate-smart reviews: €36,000
Goal of the Procurement
A climate-smart planning process that compares regular and climate-smart construction practices in Hämeentie street renovation located in Arabia district.
The objective of the planning process was to come up with the best possible technical solution for renovating the street, which would also consider the overall climate impacts.
Participants and actors involved in the procurement
The planning work was ordered by the City of Helsinki’s Traffic and Street Planning. An extensive group of the City’s representatives, for example from the units for foundation engineering and park and green area design, as well as some external parties, such as Helsinki Region Environmental Services Authority’s water maintenance unit, HSL and Helen, took part in the project group. Within the City organisation, the project manager, an environmental specialist of the Development Services, the experts of the Canemure project and the City’s mass coordinator took part in the climate-smart survey.
The planning, the emission calculation guiding it and the resource-smart reviews were implemented by Ramboll in accordance with the City’s guidelines.
The engagement of different parties in the planning process is important, as they bring the know-how of their special fields to the work and offer data to support climate-smart solutions. A review that takes climate impacts into account is still a new thing, and the projects allow the related competence in all organisations participating in the work to grow.
The street section covers about a two-kilometre of a road between Toukola and Vanhakaupunki, and it represents the densely built street environment that is typical in Helsinki. During the renovations, the street area will be repaired, the pedestrian and cycling conditions improved and the municipal technology in the area renewed. At the same time, water maintenance and district heating and cooling networks will be renewed, and the street area’s outdoor lighting will be modernised to meet today’s demands and requirements. The intention is to conduct the area’s storm waters to Vanhankaupunginlahti in the future, so the separating wastewater and storm water into different networks was also reviewed.
A carbon footprint calculation that takes into account emissions generated during construction (including the production and transport of building materials and the emissions of installation/the work being carried out) was included in the planning work to highlight the renovations’ key climate impacts. Combining the assessment of climate impacts as part of the planning allowed the comparison of regular construction procedures with resource-smart options and illustration of the emissions generated by the different planning solutions. This also revealed the emission reduction potential of utilising recycled materials and implementing a low-emission worksite. In addition to greenhouse gas emissions, the cost-effects of the proposed solutions were reviewed.
Many ways to cut down on the carbon footprint
A major part of infrastructure projects’ carbon footprint comes from their emission-intensive construction materials and well as the large amounts of soil and rock matter transported.
Emission calculation is one way of producing concrete information to support the planning process.
Significant developments have also taken place in mass coordination. The purpose of mass coordination is to look for new purposes of use for the excavated soil, aggregates and building materials generated through the City’s own construction projects. When these materials are utilised in areas nearby, the amount of waste taken to landfill, the demand for new soil and the emissions caused by transport all decrease.
The climate-smart review of Hämeentie as a part of street renovation planning is one of the cases of the Towards Carbon Neutral Municipalities (Canemure) project, which strive to make various procurements as low-carbon as possible.
The climate-smart review was brought up in the very first planning meeting. However, it was assessed that its impact options would be limited in the densely built street environment when compared to, for example, a new construction site.
The planning work’s climate-smart review specified the recycling and reuse of structural layers, rock materials and asphalt, the utilisation of recycled growth matter in the street’s green areas and the energy form used in work machinery. Additionally, the environmental impacts of separating water maintenance and storm waters, the climate burden of the trunk water pipes’ material options, the effect of traffic arrangements during the project on traffic emissions and the impact of the planning solutions on the maintenance emissions were assessed in their own separate reviews.
The emission calculation focused on the construction stage, as it is the most significant stage in infrastructure construction’s lifecycle emissions. The emission calculation following the standards of the CEN/TC 350 standard package was based on the quantities of building elements processed during the preliminary planning stage. Additionally, the work carried out and transport journeys were set to follow the policies applied in Helsinki. The reviewed solutions that took climate impacts into account as well as possible were compared to the usually implemented option (i.e. the ‘worst-case scenario’) in the project’s emission and cost calculations.
The planning progressed in good cooperation with experts specialising in the subject. The climate perspective was included in all planning meetings, where the matters in which emission cuts could be achieved were also presented. Further reviews were carried out, when necessary, and the process was refined. The planning stage took a little more than a year in total.
The climate-smart review assessed possible requirements for the procurement. More detailed results can be found in the pdf case description published by the city of Helsinki:
It is recommended that the following climate-smart measures identified in the review be entered in this project’s contract documents:
- The current asphalt will be removed by milling it instead of excavating it in pieces.
- The masses from excavation operations and the demolished paving materials will be sorted and transported in the City’s interim storage.
- The structural layer material demolished from the street will be utilised as a final filling material.
- Crushed asphalt will be utilised in the new asphalt material.
- Natural stone found in the demolished paving material will be reused in the work process, and concrete stones will be used for the City’s other projects.
- Instead of planting matter procured from external suppliers, planting mater products developed by the City from its own surplus soil will be used.
- The traffic arrangements during construction will be taken into account when designing the worksite (i.e. the emission impacts will be considered when phasing the construction).
- Instead of using fossil diesel, 80% of energy used will come from renewable diesel and 20% from green electricity.*
*Helsinki is committed to the goals related to emission classes and energy sources of work machines and heavy transport vehicles in the Green Deal agreement of emission-free worksites. The City of Helsinki’s valid procurement criteria (following the Green Deal agreement) for low-emission infrastructure worksite will be applied to the Hämeentie construction phase.
Possible challenges - Climate impacts cannot be avoided
Most resource-smart measures identified and recommended in the review could be included in the plans when striving towards the technical best solution. On the other hand, it was not always possible to implement the best possible option regarding climate impacts because the area’s cityscape and street section’s characteristics were also considered.
By following the recommendations of the resource-smart solutions for the Hämeentie street renovations, the City of Helsinki can save an estimated 308,000 kg of CO2e. This option cuts the emissions by about 27% compared to the total emissions of regular building sites. Additionally, this would total more than one third in cost savings, totalling EUR 910,000, which can be achieved through recycling and reusing materials, in particular.
The resource-smart review showed that utilisation of materials, mass coordination, reserving interim storage places and the energy source of work machinery need to be linked both to the planning and then, later, to the project’s procurement process. Based on the results, the emission and cost-savings will be notable in the project itself, but the results realised cannot be assessed until after the project has been completed. Implementing the emission calculation and the climate-smart review increased the planning costs by around 10%, which is a small addition compared to the cost savings achieved in construction.
In addition to reviewing the climate impacts during construction, planning can have a more extensive effect on the emissions generated by the area’s use, servicing and maintenance.
Possible further action steps
The Hämeentie climate-smart review is linked to the City’s other development and the intention is to also apply its results to future projects.
A climate-smart review is easy to carry out in connection with planning building and infrastructure construction, as long as the review can be linked as a part of the process early enough and when real dialogue about the options is allowed as the planning progresses, for example as a fixed part of the planning meetings’ agenda.
The method, results and solution of the Hämeentie review can be directly applied to similar planning processes of dense street environments. However, it needs to be noted that only a limited range of measures could be applied to this renovation project. Additionally, including a carbon footprint calculation is not necessary in all street projects, if the site’s characteristic emission sources and central methods can be proven otherwise.
Project Manager Eino Kattilakoski, City of Helsinki
Environmental Specialist Heidi Huvila, City of Helsinki
Mass Coordinator Mikko Suominen, City of Helsinki
Project Coordinator Reetta Huomo, City of Helsinki (CANEMURE)