Blue Green Factor norm

Oslo and neighbouring Bærum municipalities participated in developing the first version of Blue-Green Factor (BGF) in 2014. Since then the BGF became a city norm in 2019 and has been further developed into a national Norwegian Standard aimed at all municipalities in Norway. The BGF norm is a performance-based green area indicator aiming to ensure sufficient vegetation cover and surface water management in individual residential development projects. A list of outdoor blue and green surfaces and structures - i.e. nature-based solutions - are scored qualitatively, scaled by surface area, with the weighted sum divided by the total area of the project computed to a "blue-green factor" (BGF). The factor must be equal to or greater than the norm for the area of the city where the project is located. The current norm weights measures based on stormwater retention, bluegreen structure, biodiversity and recreation and amenities. In Oslo BGF supports Oslo Municipality’s “Strategy for Stormwater Management”, the Green Roof Strategy and the strategic aim of the Oslo Tree Project to plant 100 000 trees in Oslo by 2030. BGF interacts with other policy instruments to promote the feasibility of NBS on private property.

Overview

Type of instrument:

Legislative, regulatory and strategic instruments›Standards

Challenges addressed

Ecologic connectivity
Flood risk: pluvial and fluvial / soil permeability
Human health, comfort and well-being
Other, please specify

urban biodiversity habitat

Consideration of nature-based solutions:

The BGF norms aims to achieve a minimum blue-green landcover in all residential projects; promoting NBS as a means of meeting minimum requirements for stormwater retention requirements in new projects, while providing a regulatory incentive to enhance the biodiversity and amenity characteristics of the projects

Targeted (peri-)urban areas:

Green areas for water management

Derelict areas

External building greens

Urban green space connected to grey infrastructure

Good practice characteristics:

Support multifunctional NBS

Locally appropriate

Potential to be replicated / upscaled

Policy business case

Governance

Government body/bodies

Initiating body:

Municipal Planning and Building Agency

Instrument design:

Details about how the instrument was designed:

Municipal planning and building, urban environment and water and sewage agencies were involved in the design of the BGF. Non-governmental actors involved include: - an expert task force was convened to review and update the norm after two years of implementation, including representatives of private property developers, private landscape architects, research institutes and different line agencies of Oslo municipality - civil society consultation on the BGF norm has been carried out through an public hearing process, with opinions available online - research and demonstration projects have been carried out by students at the University of Life Sciences (NMBU) and the University of Oslo

Involvement of non-governmental actors:

Public sector institution (e.g. school or hospital)

Private sector, corporate, business

Researchers, university

Type of actor involvement:

Expert task force consultation

Civil society consultation through e.g. workshops, surveys

Research , demonstration and evaluation projects have been carried out by research institutes and through several M.Sc. theses

Instrument implementation:

Type of involvement:

The planning and building agency is the regulating agency for building permits in regulatory planning areas requiring BGF. The norm is a requirement of building permitting when regulatory plans specify it. Otherwise the BGF calculation is voluntary for property developers, but permit applications may be viewed more favourably where BGF is documented. The BGF norm was consulted in a public hearing process in 2019, managed by the Planning and Building Agency. The 2022 revision of the norm is under a targeted public hearing process, directed at stakeholders in planning, property development, building associations, research and development institutes working in the field

Targeted actors:

Private: household, real estate developer, business , financial

Financing

Sources of funding:

Public local authority’s budget

Budget:

Less than 50 000 €

Details about instrument financing:

Implementation of the BGF is based on a private-public cost sharing approach. The costs of assessing the BGF of a development project are carried by the developer as part of the property permitting process. The municipality covers the administrative costs of assessing BGF compliance as part of the building permitting process. This makes it difficult to assess costs of BGF in a given project, but the BGF has been designed and is revised aiming at minimising assessment costs.

Monitoring, evaluation and impacts

Is a monitoring framework in place?:

Did an evaluation take place?:

Yes

The BGF instrument was evaluated in 2021, giving rise to a revision process and public hearing in 2022. Public hearing website: https://od2.pbe.oslo.kommune.no/hoering_blaagronn_faktor/#596941,6642882,2 While the revision had not been completed at the time of writing, likely outcomes include: 1) greater spatial differentiation of the minimum BGF score for different urban types (inner city, outer city residential, small house suburban, and densification around transport nodes) and land use types (residential, education, culture, sports, public roads and pedestrian areas, new and upgrade open spaces) 2) increased weighting of climate adaptation and biodiversity conservation measures, relatively less explicit wieghting of recreation related NBS 3) a relative increase in the weighting of urban trees compared to other NBS

Achieved outcomes and impacts:

Oslo and neighbouring Bærum municipalities participated in developing the first version of BGF in 2014. Since then their approach has been incoroprated in a national Norwegian Standard aimed at all municipalities in Norway. The standard has increased national awareness among municipal governments about incentivizing multiple ecosystem services from nature-based solutions addressed primarily at stormwater management.

Success factors and lessons learned:

1) successful prior experiences in other European cities such as Berlin and Stockholm 2) a pilot development of the system for Oslo funded by the National Environment Agency; 3) political support - identification in the Municipal Plan; multi-agency collaboration (planning, environment, water and sewage); 4) science-policy inrerfaces through a series of R&D projects by research institutes; 5) national standard developed based on Oslo pilot experience leading to further positive feedback loops on methodology adjustment. 6) mutually reinforcing other instruments, including the (i) minimum stormwater run-off (20 years return) requirement and (ii) norm for minimum outdoor area in residential projects.

Sources and further information

References

List of references:

Stange, E.E., Barton, D.N., Andersson, E., Haase, D., 2022. Comparing the implicit valuation of ecosystem services from nature-based solutions in performance-based green area indicators across three European cities. Landscape and Urban Planning 219, 104310. https://doi.org/10.1016/j.landurbplan.2021.104310 ; Wilkerson, B., Romanenko, E., Barton, D.N. (2021) Modeling reverse auction-based subsidies and stormwater fee policies for Low Impact Development (LID) adoption: a system dynamics analysis; Sustainable cities and society. https://doi.org/10.1016/j.scs.2021.103602 ; Barton, D.N.; Venter, Z.S.; Sælthun, N.R.; Skumlien Furuseth, I.; Seifert-Dähnn, I. (2021). Brukerfinansiert klimaberedskap? En beregningsmodell for overvannsgebyr i Oslo. Vann 2021/4 (in Norwegian). Furuseth, S.I., Barkved, J.L., Seifert-Dähnn, I. (2021). Lokale overvannstiltak i urbane boligområder – Erfaringer fra samarbeid på Grefsen-Kjelsås, Oslo. Vann 2021/4 (in Norwegian).

Further documents

Documents:

Oslo landscape Wikimedia Commons.png

BGF norm cover.png

Photos

David N. Barton