Toolkits and models


Building natural value for sustainable economic development: Green Infrastructure Valuation Toolkit

The green infrastructure valuation toolkit has been developed to help local stakeholders make good decisions about the value of different green infrastructure options:

  • It provides a simple framework that can help identify and broadly assess the benefits of proposed green investments and existing green assets, and help decide whether those benefits directly contribute to a local economy, or provide wider non-market returns for society and the environment.
  • It provides insight into the key evidence and concepts from a wide range of sectors, including economic development and regeneration, public health, nature conservation and provides a strong platform for improved understanding and cooperation during green infrastructure projects.



Biodiversity planning toolkit

An online resource aimed at helping users to incorporate biodiversity into the planning system and new development. This is a pilot version and will be further populated before the final version is launched in June 2011.

Air quality

LAQM (Local Air Quality Management)

Helps local authorities assess their local emissions, including industrial emissions and vehicle emissions.

Emissions factor toolkit for vehicle emissions

Allows the user to calculate vehicle emissions for multiple road links based on vehicle composition, traffic speeds and road type. The toolkit produces link by link source allocation covering vehicle exhaust emissions, including brake and tyre wear contributions for PM10 and PM2.5.

Exempt model

Used to assess the effects of certain types of developments, for example a new out-of-town shopping complex, where many cars may make their journey with cold engines. The models give results as excess emissions (units of mass per metre driven) for up to 10 kilometres from the vehicles. Further work is required independently of the model to calculate concentrations.

UFORE (Urban Forest Effects Model)

Computer model that calculates the structure, environmental effects and value of urban forests. The tool uses air dispersion and particulate interception models to predict the PM10 concentrations both before and after green space establishment. An inventory is conducted and trees are measured for their economic value in absorption of air pollution, and this can be used to educate people on the economic value of urban woodland. The model will enable those involved in green space establishment to select species for maximum PM10 removal, target tree establishment to those areas posing the greatest risk to the population and monitor the success of such schemes.


Used to assess current and future air quality with respect to the air quality standards such as the EU Air Quality Directive, UK NAQS. It is used to model the impact of major developments such as airport expansion and traffic management schemes. DEFRA (UK Department for the Environment) has contracted CERC to use ADMS-Urban to model air pollutants in a number of urban areas in the UK, including London.

CiTTyCAT (Cambridge Tropospheric Trajectory model of Chemistry and Transport)

Used to investigate ozone production and transport based on factors such as temperature, humidity, pressure and surface pressure.


Analyses the ecological and economic benefits of tree canopy and other green space, in order to calculate the economic/cost benefits for the services provided by the trees and other green space in a specific area. The air pollution model was developed by the US Forest Service and calculates the pollutant removal capacity of tree canopy. The results of the model show how much of five air pollutants the tree canopy is removing from the atmosphere. The greater the tree canopy, the more air pollution is removed. CITYgreen reports the annual quantity of pollutants removed and the dollar value associated with these services.


A multi-media fate and transport model that includes logarithms for pollutant deposition. The output concentrations from TRIM.FaTE can also be used as inputs to a human ingestion exposure model, such as TRIM.Expo-ingestion, to estimate human exposures.

Lacors Air quality toolkit

Aimed at councillors and environmental protection officers and provides practical examples of how councils can address the problem of poor air quality. Many councils have already set up innovative schemes or strategies to reduce air pollution levels. For example, London Borough of Greenwich has imposed levies on developers to finance air quality management schemes during urban planning and Manchester City Council has started to issue fixed penalty notices to drivers who refuse to switch off their engines whilst stationary.



GIS software developed in the US as an extension to ESRI’s ArcGIS. The CITYgreen toolkit calculates the volume of runoff coming from the land cover, based on a 2 year, 24-hour rain event. More impervious surfaces generate higher levels of runoff, while more natural areas decrease the amount of runoff. This can be a modelling tool for planning and zoning. CITYgreen reports the runoff volume and economic value (in US dollars) associated with removing any excess storm water resulting from changes in land cover, such as constructing a retention or detention pond.  A review investigating the applications of CITYgreen and the economic benefits in the UK concluded that it can only be applied in the US due to underlying models being based upon US environmental data. CITYgreen has excellent potential for use in the UK but will currently not provide accurate results when used in other countries, unless local data are used to populate the models (Kingston et al., 2009).

Hydrus 1D, 2D and 3D

Computer programmes provide a Microsoft Windows-based modelling environment for the analysis of water flow and solute transport in variably saturated porous media. Weather data from any location can be input into the model to determine runoff for any depth modular-block green roof using a similar soil media type (Hilten et al., 2008). The models have been in the marketplace for two years and although a useful tool, the complex package requires skill and understanding in modelling and setting of the exact parameters a user requires. HYDRUS can accurately predict runoff especially for small rain events. At larger rainfall quantities, HYDRUS appears to over predict. Storm data collected as part of a green roof study in Athens, Georgia, USA were used to validate HYDRUS-simulated runoff.

i-Tree Hydro 

i-Tree Hydro is in the final stages of development and is due to be released in 2010.  This package simulates the effects of changes in tree and impervious cover characteristics within a watershed river catchment on stream flow and water quality. It was designed specifically to handle urban vegetation effects so that urban forest managers and urban planners can quantify the impacts of changes in tree and impervious cover on local hydrology to aid in management and planning decisions. Model results can be used to improve urban forest management and urban planning and design in order to help improve water quality and reduce the risk of flooding. This package holds good promise for application in the UK, but is likely to require UK specific climate, tree species and local geographical data.

i-Tree Vue

Utility is still in development which uses land cover data maps and compiles data on a specific area with regards to per cent impervious cover and per cent tree canopy. This could be a useful tool in the future to assess land use in urban areas which will address flooding issues and determine the best places to site urban drainage.


This system uses two main models to give a range of ecosystem service values: UFORE, or the Urban Forest Effects Model; and STRATUM, the Street Tree Resource Analysis Tool for Urban forest Managers. This method has been adapted for use in other countries, but needs local climate and tree species data. 

Heat amelioration


A GIS based system used to calculate the economic benefits of urban forests; this program needs detailed land use data to be effective. A recent study carried out by Manchester University on behalf of Natural Economy Northwest detailed a number of key points that would need to be addressed before this software could be used effectively in the UK. Since both CITYgreen and i-Tree use the same models for calculating ecosystem service values, it may be possible that some of the criticisms directed at CITYgreen by this report may also apply to i-Tree.


Consortium research project run by Manchester University’s Centre for Urban and Regional Ecology. One of the main aims of this project is to develop tools that can quantify risk from the combined effects of the UHI and climate change, and show how best to target adaptation strategies over a large urban area. SCORCHIO is scheduled to run through 2010, after which time more information on the proposed GIS tool may become available.


Consortium project lead by University College London, looking at developing more localised tools for quantifying the effects of building structure and form, climate, energy use and effects on human health.

Right trees for a changing climate

Database that helps decision making on tree planting and the risks of climate change to urban trees and shade provision. A GIS system for quantifying temperature differences and UV exposure using different tree species. Models are usually used to characterise urban surfaces as part of a larger mesoscale meteorological model.

Water quality

South East Water Management Climate Change Adaptation Planning Toolkit(PDF-418K).

Focuses on three key areas of climate change adaptation for ‘water-related’ impacts, and how these measures can be delivered through the planning system. The toolkit covers climate change adaptation responses to address:

  • Flood risk
  • Water resources and water supply issues.
  • Water quality issues (to the extent to which adaptation options to address flood risk and water resource issues have dual benefits for water quality e.g. certain types of Sustainable Drainage Systems (SUDS)).
  • Water related impacts on built structures (such as increased weathering of facades).

Toolkits for Greener Practices

Low/No Discharge Stormwater Management Strategies aiming to reduce quantity of storm water runoff from the site or improve the quality of site runoff before it discharges to storm sewers that deliver runoff to area lakes and rivers and before it percolates into groundwater. Use of on-site water infiltration or retention as a means of improving the quality of surface water runoff. Design of new storm water systems to prevent discharge of unmanaged storm water into jurisdictional wetlands, sole-source aquifers, trout streams or other sensitive areas. Inclusion of wetlands, grassed swales [depressions and ditches], natural vegetation, properly designed extended detention ponds, bioretention and infiltration devices are all effective in reducing runoff volumes from and increasing infiltration at the site. Bioretention practices are designed to mimic naturally vegetated areas, controlling water flow and quality through infiltration and evapotranspiration. Rainwater and rooftop gardens are included among the alternative techniques. Collection systems can be designed for storm water reuse as irrigation water.

The Urban Green space toolkit

Issued by the Wildlife Trusts is a 'how to' document aimed at groups trying to create and improve local green space (Calvert et al., 2007).  It contains information in colour-coded sections on objectives and evaluation, creating community groups, partnership working, land management and dealing with problems, and funding.  It contains 'snippets' of case studies clearly referred back to sources. 

Environmental quality


Developed as part of the KLIMES project at the University of Mainz, Germany (Bruse and Fleer, 1998). The ENVImet software and is capable of predicting the effects of differing amounts of vegetation on different climate scenarios for a given urban area. However, modelling with ENVImet can be time consuming and ideally needs large amounts of processing power. ENVImet can also be used in conjunction with BOTworld software to look at the effects of its modelled climate scenarios on human thermal comfort (Huttner et al., 2009; Bruse, 2009).

Confirm (PDF-500K)

An infrastructure management software system that enables the management of: roads and other highway infrastructure; property; parks; trees; refuse collection and waste management; and streetlights. Has an asset management module that can log what and where an asset is, and any work that has been completed on it. It can calculate the asset value using any formula required, such as historic cost, replacement value.


A tree management system that records the condition and full history of a tree including enquiries and work undertaken. Information linked to digitised map. Can be used to generate valuations using a simplified version of CAVAT.

Towards an excellent service (TAES)

A diagnostic tool for green space management organisations to accurately define performance against a model of best management practice. TAES improves user satisfaction, staff satisfaction, efficiency of delivery for user needs. TAES covers: standards of service, use of resources, policy and strategy, leadership, performance management and learning, people management, partnership working and community engagement.

The Helliwell system

System for visual amenity valuations of trees and woodlands.  Valuation of trees based on:

  • a tree’s size, location, suitability, life expectancy, shape and proximity to other trees
  • woodland size, position, viewing population, proximity to other woodland, structure, compatibility.

Overall score equates to a monetary value derived from the cost of purchasing extra large trees, linked to the retail price index. 

Capital asset value for amenity trees (CAVAT)

System for managing publicly owned trees; accounts for value of trees as public assets. Developed by London Tree Officers’ Association (LTOA) to value trees in relation to insurance claims for tree-root damage. Derived from the USA’s Council of Tree and Landscape Appraisers ‘trunk formula’.  Trees are assessed on four variables:

  • basic value/size (based on trunk area, nursery prices and planting costs)
  • functional value/functional status
  • adjusted value/individual factors (location, amenity value and appropriateness)
  • full value/life expectancy.

Regeneration of contaminated land

Public Benefit Recording System (PBRS)
PBRS was originally conceived by the Forestry Commission and the Northwest Regional Development Agency to assist in the selection of derelict land sites for regeneration in their pioneering Newlands land reclamation scheme, a site based approach from which it has evolved into both a sites and landscape tool that has been used in a broad range of projects.

Contaminated Land Exposure Assessment (CLEA) model

CLEA is the Government supported methodology for estimating the risks to people from contaminants in soil on a given site. It determines acceptable levels for contamination in soil below which the risks are considered minimal, under Part IIA of the Environmental Protection Act 1990.

Risk-based corrective action (RBCA) toolkit

Corrective action strategies that categorise sites according to risk, and move all remedial sites toward completion using the appropriate levels of action.

Risc Human

Windows-based computer tool that can be used to estimate human exposure to contaminants in soil, groundwater and sediment, and is a method for deriving site-specific human health assessment criteria for contaminants in soil.


Social Return on Investment (SROI) framework

Framework for measuring and communicating a broad concept of value, incorporating social, environmental and economic costs and benefits. The framework concentrates on change and measures outcomes using monetary values to represent them. SROI is based around stakeholders and puts financial values on the impacts identified as important by stakeholders that do not have market values. This means that social benefits and values, which are often excluded from markets and economic analyses, can be considered in the same terms, i.e. monetary terms, so that they can be more easily incorporated into resource allocation decisions.

SROIs can either be done retrospectively as an evaluation of outcomes that have already taken place, or as a forecast predicting the social value that will be created. In simple terms, SROI involves establishing scope and identifying key stakeholders. It is important to have clear boundaries about what your SROI analysis will cover, who will be involved in the process and how.

Health Impact Assessment (HIA)

HIAs have been defined by the international Gothenburg consensus as ‘a combination of procedures, methods and tools by which a policy, program or project may be judged as to its potential effects on the health of a population, and the distribution of those effects within the population’ (Greenspace Scotland, 2008: 37). A HIA is not an economic valuation tool but it can be used to systematically identify the positive and negative health and well-being impacts of proposed plans, policies or projects on individuals and communities. HIAs can be used to look at individuals’ physical and mental health as well as their well-being more generally and community well-being. 

National indicators

Can be used by local authorities to assess the general satisfaction of residents of an area, including perceptions of anti-social behaviour and participation in recreation in urban green spaces (Communities and local government, 2008).

Green infrastructure health check

The Government’s adviser on urban design, CABE, is calling on urban local authorities to assess the health of their green infrastructure. Launched as part of CABE’s ‘Grey to Green’ campaign, the GI health check is an online tool for urban councils in England to find out how well they are prioritising their green spaces. The ten GI health check questions ask councils to assess the priority given to green spaces and the staff and resources to manage them. Local authorities will receive feedback that rates their performance, helping them identify where they need to make improvements, as well as inviting them to participate in CABE’s GI pilots.

Planning for brownfield regeneration

The 'PRiSM' project management tool and accompanying practice note present the stages and tasks of brownfield regeneration, with detailed information concerning their characteristics (type, status, inputs, outputs), and the implications of the stage and tasks to regeneration delivery and the skills required to deliver them. The process presented is the ‘ideal’ approach to regeneration focusing on woodland end use; however the process is equally applicable to other forms of greenspace.