B£ST (Benefits EStimation Tool)


B£ST (Benefits EStimation Tool) is an Excel spreadsheet tool which provides guidance to estimate the monetary benefits of Blue Green Infrastructure (BGI), including Sustainable Drainage Systems (SuDS) and Natural Flood Management (NFM), without the need for specialist economic input.  Estimates are based on the performance of the whole system rather than individual components.

B£ST begins with simple qualitative assessments to quickly identify which benefits should be evaluated further. B£ST provides support to help quantify and monetise each benefit chosen. On completion of the evaluation, a series of graphs and charts present the benefits in terms of ecosystem services and natural, social and other capitals. B£ST can support investment decisions, help to identify stakeholders and find potential funding routes.


Site and project data in Excel spreadsheets.

Quantitative data on ecosystem services
Tables / statistics / reports
Economic assessment
Ecosystem service impact score / Development impact score
Cost-benefit assessment
Site scale
Local scale
Landscape scale
Regional scale
Cost of the tool (and guidance): 
Open access (free)
A range of land uses, generally urban.
Resource requirement (software): 
Microsoft Excel
Level of technical expertise required: 
Excel skills
Internet use skills
Types of ecosystem service included: 
Habitat type (UK NEA habitats): 
Mountains, moors and heaths
Semi-natural grasslands
Enclosed farmland
Freshwater, wetlands and floodplains
How does it work?: 

The benefit categories most appropriate to assess for a scheme are selected through initial qualitative screening questions. This also enables a high-level indication of the potential range of benefits provided from limited input information.  Site-specific data is then entered for the chosen categories.

B£ST is based on robust research evidence and provides a structured approach to evaluating a wide range of benefits. Where feasible, it enables benefits to be quantified and monetised. Summary tables present results under the Ecosystem Services (ESS) framework and in terms of natural, social and other capitals. A series of graphs are automatically generated for use in reports. An Option Comparison Tool enables data from more than one assessment to be compared against baseline in terms of net present cost, benefit and value. B£ST enables a robust, standard approach to assessing the benefits of BGI that is consistent with broader (e.g. government) economic appraisal guidance.