The green infrastructure valuation toolkit user guide

Building natural value for sustainable economic development: The green infrastructure valuation toolkit user guide
Preparation
Step 1: Initial analysis
Scope and gather the information needed on the purpose, physical
characteristics and beneficiaries of the project or site being assessed.
Good information about the project or asset to be valued is essential. The better
the information, the greater the accuracy of the valuation. A checklist of the
initial data requirements is provided in Appendix 2.
Core information such as the type, quantity and location of a green asset, its
current and future use and so on, should be readily available from the project
developers or asset owners.
Step 2: Identifying beneficiaries
Estimate the number of beneficiaries from the project or site being
assessed. This will be needed for assessing recreation, tourism, health and
property benefits.
Many of the benefits of green infrastructure come from its use by humans – for
recreation or tourism. Baseline figures for current use are therefore important to
help assess the net additionality* of the green infrastructure investment – the
net positive difference resulting from the investment.
The affected population will be an estimate of the relevant ‘user’ and ‘non-user’
population – the beneficiaries of the investment.
‘Users’ benefit directly, by using the new or improved green
infrastructure - think of people using a park, or a new cycle path.
‘Non-users’ may also derive a benefit - for example, a city dweller may
value investment to safeguard a rural habitat even if they have no
intention to visit the site.
In many cases, the most appropriate approach to identifying beneficiaries will be
some form of population or household density or catchment analysis.
Understanding this is important, as the value given to a green infrastructure
investment - and in particular non-marketed goods - is sensitive to distance.
There is a reduction in value further away from the green asset.
Some methods commonly used to estimate the number of potential beneficiaries
include:
Method 1: Density of use. Where the proposed investment involves the provision
of a cycleway or footway it is possible to estimate the likely level of use based on
density values from other sites or areas.
British Waterways’ economic impact model uses national data on
density of use for walking and cycling per kilometre
local authority leisure services departments may also have local leisure
use data to draw upon.
Method 2: Population penetration analysis. This approach estimates the likely use
of the green asset by local residents or visitors, based on taking a percentage of
the relevant population. It draws on household population data. The percentage
penetration can be based on evidence from other areas or green infrastructuretype
projects or a bespoke leisure use study.
Method 3: Catchment analysis. This method is useful to determine the relevant
beneficiaries of green infrastructure investment - for example the number of
residential or commercial properties within a certain visual range or travel-time
distance.
This type of analysis is also useful for estimating non-user benefits. Here the aim
is to identify the relevant household population that may value the green asset for
its option use* or existence. This may be based on a geographical area or drive
time, depending on the findings from the evidence base.
Method 4: Site transfer
This estimates the likely total number of visits based on the experience of other
similar sites. For example, a woodland of 50 hectares with 25,000 visits per year
has a density of use of 500 people per hectare per year. This can be applied to
your project, based on the scale of your site.
Calculating catchments
The Greater London Authority (GLA) publishes guidance on the preparation of
open space strategies, which includes a series of catchment areas:
regional parks, of up to 400 hectares in size and catchment area of 3.2
to 8 kilometres
district parks of up to 20 hectares and catchment area of 1.2 kilometres
local parks of 2 hectares serving the local population within 400 metres.
Other councils have drawn on the GLA’s guidance when working up their own
strategies. For example, Kirklees 2007 open space assessment modified the
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