Nature Outcomes Catalogue — Calculate your project cost

1. Project details

Define the project at the top level, what it does, where, and over what period.

Project name

Location

Protection or restoration

Project description 280 characters remaining

Project lifespan

30 years

2. Primary outcome

The priority environmental outcome this project is designed to deliver. Cost-effectiveness will be based on the cost to deliver each unit of this outcome.

Primary outcome

Outcome unit(auto)

Outcome quantity

How was this outcome quantified? (optional) 0/400

How this outcome scales over time ℹNature outcomes do not accrue in a straight line — a woodland takes decades to mature while a flood barrier delivers most of its benefit immediately. The delivery curve describes how your outcome builds up year by year, and affects how cost-per-outcome is calculated in the Normalised view for projects longer than 30 years.

Shape assignments are derived from field evidence (RSPB, Natural England, Forestry Commission, Environment Agency and others). The justification for your outcome's default shape is shown in the ℹ next to the shape pills.

Pick the delivery curve that best fits how this outcome materialises, and adjust the timing within the evidence-based range. The curve appears in the outcomes box on the right.

Select a primary outcome above to choose its delivery pattern.

3. Co-benefits (optional)

Additional environmental outcomes the project produces alongside the primary one. These are recorded but not priced, the catalogue prices outcomes one at a time.

Co-benefit

4. Direct costs

The cash costs of designing, building, and maintaining the project. One-off development and capital costs at the start; ongoing maintenance over the project's life.

Development cost (£)

Capital cost (£)

Annual maintenance (£/yr)

Maintenance period (years)

15 years

5. Opportunity costs

The value foregone by using land for nature rather than its next-best alternative use, usually farming income.

Opportunity cost typeℹHow opportunity cost is treated for this project.

Minimal opportunity cost, for projects on land with little or no productive alternative use (e.g. derelict urban sites, unproductive uplands, river corridors). Opportunity cost is set to zero or near-zero.

Foregone income from farming, for projects taking productive agricultural land out of food production. Opportunity cost equals the farm income that would otherwise have been earned, by land grade and farm type.

Other, for projects where the foregone use is neither agricultural nor negligible (e.g. forestry, development land). Enter the foregone value manually.

DescriptionℹOptional free text, for example the basis of the opportunity cost figure, any non-agricultural foregone uses, or notes on why this project sits at the low or high end of the range. 0/50

Project area (ha)

Use land grade proxy?ℹLand grade is a standard measure of agricultural productivity. Each UK nation classifies its land on a scale from the most productive (capable of growing a wide range of crops) to the least productive (severely limited for agriculture). It is a reasonable proxy for the income a hectare would generate under typical farming.

Select Yes to use a lookup table of typical net farm income by land grade. Select No to enter a per-hectare opportunity cost manually, for example if you have farm accounts or a specific local figure.

Manual opportunity cost (£/ha/yr)ℹThe farm income foregone per hectare, per year, by taking this land out of production. Use net farm income (revenue minus variable costs and direct payments), not gross output. If you do not have a specific figure, enable the land grade proxy above for a standard lookup value.

6. Financing & delivery

Choose how each cost is funded, and — optionally — the delivery mechanism it runs through. The mechanism list is filtered to what fits the funding type and grouped by delivery category; a project can carry several. The cost of capital reflects each funder's return expectations: grants, donations and self-financing carry zero; investment carries a variable rate.

Commitment period

15 years

Development finance source Delivery mechanism (optional)

Capital finance source Delivery mechanism (optional)

Maintenance finance source Delivery mechanism (optional)

Opportunity finance source Delivery mechanism (optional)

Repayment approach (applies to investment)

Annualised cost of capital

Grant or donation 0% ℹNo financing cost is applied to grants or donations. The 3.5% HM Treasury Green Book discount rate is used to compute the present value of the project, not as a cost of capital.

Investment — ℹThis represents the investor's target internal rate of return (IRR), expressed in real terms.

The suggested default is the UK gilt yield for your commitment period plus a 4% private-investment premium (table below).

You can override it — click Modify rate to set your own cost of capital.

TenorGiltPrivate1yr−0.6%3.4%2yr−0.3%3.7%3yr0.1%4.1%5yr0.7%4.7%10yr1.4%5.4%15yr1.7%5.7%20yr2.0%6.0%25yr2.1%6.1%30yr2.2%6.2%40yr1.9%5.9%50yr1.8%5.8%60yr1.8%5.8%
Gilt yields: UK Debt Management Office and Bank of England published yield curves, via giltsyield.com/bond/inflation
Green Book STPR (3.5% real): HM Treasury, The Green Book (2022)
Correct as of April 2026.

Cashflow 0% ℹNo financing cost is applied. Projects funded directly out of operating cashflow carry a 0% rate.

Delivery mechanisms on this project

None — assign one to a funding type above.

7. How costs scale to the 30-year window (optional)

8. Sources

Evidence base for the outcome quantification and cost figures entered above.

Source 1

Source 2

Source 3

Delivery mechanisms on this project

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