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Green Business

Including green criteria for window cleaning services

Case study of the City of Copenhagen, Denmark

Subject matter: Transport and cleaning products

Environmental and social impacts targeted:

  • Green vehicles: Reduction of GHG emissions and increase of fuel efficiency through the uptake of green vehicle use.
  • Social clauses: Prevention of social dumping
  • Ecolabelled cleaning supplies: Reduction of hazardous chemicals, water consumption and discharge, raw material use

Relevant EU legislation/policy/guidance: EU GPP Criteria for Road Transport and EU GPP Criteria for Indoor Cleaning Products and Services


With a population of over 650.000, the City of Copenhagen is both the capital and the most populous city in Denmark.

In 2012, Copenhagen adopted the CPH 2025 Climate Plan (2012), a holistic strategy that includes specific targets and initiatives in four key areas – energy consumption, energy production, mobility, and city administration. 

As part of this climate plan’s third implementation phase (2021 – 2025), the city introduced a flagship project dedicated to green the transport used fulfilment of activities of goods and services contracts through the stipulation of stricter demands in its tenders for emission-free and low-emission deliveries. The requirements have been initially introduced in public procedures addressing locksmith services, electrician services and window washing.

Additionally, while over 21,500 ecolabelled products and services currently exist, the City of Copenhagen continues to work to stipulate even more requirements for the ecolabelling of its purchases.

Image of 3 persons cleaning windows
Photo by Nuno Silva


Procurement objectives

In 2022, the City of Copenhagen sought to procure window cleaning services for the buildings under the jurisdiction of its Child and Youth Administration. The Child and Youth Administration is primarily responsible for the coordination and daily planning of activities for children and young people attending Copenhagen’s almost 70 primary and lower secondary schools, and 600 institutions. 

The city decided to include green vehicle criteria in the tender, which was novel for a window cleaning contract. Preliminary market consultations were held to communicate the purpose of the requirements and understand the perspectives of potential bidders.

Although suppliers were generally open to the criteria, some expressed concerns that overhauling recently purchased non-compliant fleets of vehicles would create unforeseen burdens. Therefore, the city implemented a ‘staircase model’ as a contract performance clause whereby the minimum required level of adherence increased by a percentage amount every year of the contract. Another consideration taken from the preliminary market consultation, and as a direct consequence of Covid-19, was the removal of the green vehicle requirement for the first year of the agreement. In these ways, early market engagement allowed for the development of ambitious yet realistic criteria.

Beyond the green vehicle criteria, Copenhagen also considered other green and socially responsible measures. Since 2017, the city has demanded that products and services in 26 selected categories – including cleaning products – are certified with a type I ecolabel, such as the Nordic Swan Eco-label or EU Eco-label. Furthermore, since 2011, Copenhagen has countered social dumping by requiring fair pay and working conditions for every individual working on city assignments. These stipulations are included in contracts as labour clauses.

Tender requirements

The subject matter of the contract was the provision of window cleaning services for the City and Youth Administration. The framework agreement covers all glazing present on the administration’s property, including internal, external, intermediate, and internal glass and skylights. An open procedure was used.

Contract Performance Clauses:

According to the Procura+ Manual (2016, p. 63), “many of the impacts which sustainable procurement aims to address will only arise during the delivery of a contract – particularly for services and works”. Engaging with suppliers during the development of ambitious yet attainable performance clauses reduces ambiguity and promotes buy-in from both sides.

Following market dialogues, the City of Copenhagen introduced a contract performance clause obliging suppliers to use green vehicles while carrying out the duties indicated in the window cleaning contract. This clause relates to one of the several defined actions within the city’s CPH 2025 Climate Plan roadmap – namely, a commitment to solely acquire vehicles and equipment that run on alternative fuels whenever possible. For this agreement, ‘green vehicles’ were defined as “vehicles powered by electricity, biogas or hydrogen and plug-in hybrid vehicles... [or] other non-motorized modes of transport”. While there were no obligations to purchase vehicles in this window cleaning tender, it was a requirement that a specific percentage of service deliveries were made using ‘green vehicles’.

The table below displays the ‘staircase model’ of supplier obligations concerning green vehicles. Under the model, suppliers must commit to operating an annually increasing percentage of green vehicles over the contract periods. As a direct consequence of Covid-19’s impact on green vehicle delivery, the use of green vehicles was not required in the first year of the agreement.

01/09/2022 – 01/09/20230%
02/09/2023 – 01/09/202440%
02/09/2024 – 01/09/202560%
02/09/2025 – 31/08/202680%

The supplier's other vehicles must at least comply with the Euro 6 emissions standards.

The CPH 2025 Climate Plan roadmap describes efforts to strengthen systematic monitoring of supplier compliance with procurement requirements to ensure that the desired effect is achieved. For this contract, the supplier is obliged to state on all invoices the total number of journeys carried out with green vehicles and conventional vehicles, along with the registration number of the vehicle(s) used. The contracting authority monitors the use of vehicles based on the registration numbers of the cars used and, when requested, through supplier-documented GPS tracking. Once a year, the contracting authority calculates whether the supplier has achieved the minimum level for the use of green vehicles.

If the calculations show that the supplier has not achieved the specified minimum level, the supplier will be given the opportunity to comment on this. If the contracting authority still believes that the supplier has not fulfilled its obligations a penalty may be enforced, calculated as a sanction for each percentage point of non-compliance with the supplier’s obligation to use green vehicles and set at DKK 5,000 [EUR 670] per percent underperformance.

Another performance obligation referred to Copenhagen’s comprehensive ecolabel policy: the supplier is required to use window cleaning supplies with the Nordic Swan or other type I ecolabel.

Beyond environmental considerations, social requirements were present in the tender as contract performance conditions. These included a “Labor Clause” requiring fair wages (in line with collective bargaining agreements) for all workers involved with carrying out the service, and a “CSR appendix” requiring suppliers to take social responsibility, as described in the UN guiding principles for business and human rights and OECD guidelines for multinational enterprises.

Image of a green leaves forming a car
Photo by RoadLight



The invitation to bid was published in February 2022 and received four bids. The tender was awarded in May 2022 to two suppliers and the four-year framework agreement began on 1 September 2022. The framework agreement covers three districts in Copenhagen and is worth approximately DKK 12 million [EUR 1.6 million]. Given the inclusion of challenging environmental criteria in the performance requirements, the contract award criteria only related to price. Contractors indicated priority districts in their bids.

Environmental impacts

The City of Copenhagen purchases around DKK 15.7 billion [EUR 2.1 billion] worth of goods and services annually, making public procurement a helpful tool for nudging the market in a more sustainable direction. Through this tender, Copenhagen has used environmental criteria to address the impact of its vehicles and cleaning supplies.

The transport sector is responsible for almost a quarter of Europe’s greenhouse gas (GHG) emissions, with road transport accounting for 77% of all EU transport GHGs. According to the Technical Report on the Revision of the EU Green Public Procurement Criteria for Road Transport (2022). Since the main environmental impacts of transport vehicles are related to the use phase, the primary technical options for reducing emissions are making internal combustion engine vehicles more fuel-efficient through hybridisation or switching to fully electric or fuel-cell vehicles. Therefore, mandating green vehicle requirements can incentivise wider uptake and thus potentially decrease the local public sector’s total amount of GHG emissions.

The contracting authority is committed to expanding and strengthening the use of green vehicle criteria. In 2022, eight tenders included enhanced green vehicle requirements while in 2023, stricter green vehicle standards are expected to be set in 16 new tenders. Furthermore, the city plans to change the definition of ‘green vehicle’ to no longer include plug-in hybrids. This change is due to new research on the environmental impact of plug-in hybrid vehicles and the prevalence of greener, alternative options. This demonstrates Copenhagen’s proactive sustainability action. 

According to the Technical Report on the Revision of EU Green Public Procurement Criteria for Indoor Cleaning Services (2018), the key environmental impacts of cleaning services include the cleaning product formulation and raw material use, manufacturing and end-of-life of cleaning products, energy and water consumption, and waste discharge or generation. The report states that using eco-labelled cleaning products provides a reliable way of identifying environmentally friendly cleaning products and decreases the administrative burden on companies. GPP criteria include products labelled with the Nordic Ecolabel in the scope of the ecolabel criterion. The Nordic Ecolabel for cleaning products meets strict requirements concerning, among others, hazardous chemicals, cleaning performance, and packaging standards. By stipulating requirements for the ecolabelling of cleaning service products, Copenhagen can reduce the environmental impact of their production and consumption. 

Lessons learned

  • Maintaining ongoing dialogues with the market allows Public Authorities to clearly describe their objectives to suppliers and gain a better understanding of the market.
  • Ensuring that market dialogues are open and transparent by publishing shared information and allowing for questions or comments on proposed criteria can mitigate potential conflicts of interest.
  • Implementing a staircase model, whereby sustainability demands on suppliers are increased on a regular basis over time, could retain the interest of bidders who may be otherwise disenchanted by highly demanding criteria upfront.
  • Introducing ambitious contract performance clauses can ensure the gains of sustainable and socially responsible procurement are reflected in the way a contract is carried out.

More information

For related information, please see European GPP Criteria for Road Transport and the Technical Background Report. Please also see the European GPP Criteria for Indoor Cleaning Products and Services and the Technical Background Report.