Planning gain explained: what a development can contribute

 

Planning gain is an informal term for the benefits, infrastructure and contributions secured from development through the planning system. In practice it commonly means things such as affordable housing, new or improved infrastructure, financial contributions and other obligations secured through a Section 106 planning obligation, together with the separate Community Infrastructure Levy (CIL).

There is an important limit. Planning permission is not something a council can sell in return for unrelated benefits. A contribution must have a proper planning basis, and Section 106 obligations are subject to statutory tests which prevent a council from simply asking for whatever would be useful locally.

This page explains what people usually mean by planning gain, how Section 106 and CIL differ, when developer contributions can lawfully be sought, and where Vacant Building Credit fits into the picture.

 

What does planning gain mean?

 

Planning gain is not the name of a single tax, charge or statutory power. It is planning shorthand for the public or community benefits that can accompany development.

Those benefits can be delivered in different ways. A housing scheme might provide affordable homes on the site. A larger development might pay towards school places, transport or open space. A developer may have to carry out highway works. In an area which charges CIL, the development may also generate a separate levy payment towards infrastructure.

The important point is that these mechanisms are not interchangeable. A Section 106 obligation is tied to the particular development and its planning impacts. CIL is a levy calculated under a charging schedule and can help fund infrastructure more widely. A Section 278 agreement deals with works to the highway. They may all affect the same project, but each has its own legal basis.

 

Planning gain is not planning uplift

 

The two phrases sound similar but describe opposite sides of the development equation.

Planning gain, as we use the term on Planning Geek, is what the development provides back through planning obligations, infrastructure and related contributions. Planning uplift is the increase in land value which can arise because planning permission, an allocation or a stronger prospect of development changes what land is worth.

A development can create both at the same time. Permission can increase the value of land while the permission also carries obligations and infrastructure costs. They should not be confused, and our separate Planning Uplift guide explains the land-value side.

 

Section 106: the main negotiated planning gain

 

Section 106 of the Town and Country Planning Act 1990 allows a person with an interest in land to enter into a planning obligation. The obligation can restrict the development or use of land, require specified operations or activities, require the land to be used in a specified way, or require money to be paid.

A Section 106 obligation runs with the land and can therefore continue to bind later owners. It is also registered as a local land charge.

Common subjects include:

• affordable housing
• education, health or community infrastructure where the development creates the need
• open space, recreation or public-realm provision
• transport measures and travel-plan obligations
• site-specific ecological or mitigation measures where a planning obligation is the appropriate mechanism
• financial contributions towards works or facilities directly related to the development
• restrictions or requirements controlling how land is used

The detailed mechanics of Section 106, unilateral undertakings, modification and discharge are covered in our Planning Agreements and Obligations section.

 

The three legal tests for a Section 106 contribution

 

The Community Infrastructure Levy Regulations 2010 put three important tests on planning obligations used as a reason for granting permission. The obligation must be:

• necessary to make the development acceptable in planning terms
• directly related to the development
• fairly and reasonably related in scale and kind to the development

The same tests are reflected in national planning policy and guidance.

This is why the phrase planning gain can be misleading if it sounds like a general opportunity for a council to extract value. A council cannot lawfully turn a planning application into a shopping list of unrelated local projects. If the obligation is not needed to make the proposal acceptable, is not connected to the development, or is disproportionate, it should be challenged.

Formula-based local policies can help calculate contributions, but the decision-maker still has to ensure that the obligation sought in the individual case satisfies the statutory tests.

 

Monitoring fees are allowed, but they are not unlimited

 

A Section 106 agreement can include a monitoring fee to cover the authority’s cost of monitoring and reporting on the delivery of the obligations. Government guidance says the fee must be proportionate and reasonable and reflect the actual cost of monitoring.

That matters because a monitoring charge is not simply another source of planning gain. It is supposed to pay for the work involved in administering the obligation. A fee which is excessive or detached from the actual monitoring task can be questioned.

 

What is a commuted sum?

 

A commuted sum is a financial contribution paid instead of, or in connection with, physical provision. The phrase is used in several planning and infrastructure contexts.

For example, a planning obligation might secure a cash contribution where an affordable housing requirement is being met off site, or require money towards open space or another facility rather than the developer providing the whole facility directly. The agreement should say when the payment becomes due and what triggers it.

Commuted sums are not automatically lawful just because a local policy contains a calculator. Where they are secured through Section 106, the contribution still has to satisfy the three statutory tests.

Do not confuse this with a commuted maintenance sum under a highways or drainage agreement. Those agreements sit under different legislation even though the same phrase is often used.

 

CIL is different from Section 106

 

The Community Infrastructure Levy is a separate charging system created under the Planning Act 2008 and the CIL Regulations. It is not negotiated afresh for every application.

A charging authority which has adopted a charging schedule sets rates for categories of development. Liability is then calculated under the regulations, usually by reference to floorspace, the charging rate and indexation. CIL can be used towards infrastructure needed to support development across the area.

Section 106 and CIL can both apply to the same permission. The distinction is broadly:

• CIL helps fund wider infrastructure through a published charging regime
• Section 106 deals with obligations and mitigation sufficiently connected to the particular development

As at August 2026, CIL remains very much a live system. In June 2026 the Government said it remained committed to strengthening and improving the CIL regime. See our CIL section for liability, exemptions, forms, calculations and appeals.

 

Affordable housing is one of the biggest forms of planning gain

 

Affordable housing on market-led residential schemes is commonly secured through Section 106. The amount starts with the development plan and national policy, but the final obligation can also be affected by the type and scale of development, site circumstances, viability and any national policy mechanisms which apply.

A current example of how ambitious plan policy can affect scheme economics is Manchester’s Regulation 19 Local Plan. It uses 30% affordable housing as the starting point for major schemes, with a proposed 70% social-housing share within the affordable provision. See our Manchester Regulation 19 analysis, which also looks at the proposed affordable-rent requirement for purpose-built student accommodation.

Government guidance says that where up-to-date plan policies set out the contributions expected from development, a policy-compliant application should normally be assumed to be viable. If an applicant argues that particular circumstances justify a viability assessment at application stage, it is for the applicant to demonstrate that case, and the assessment should follow the national viability guidance.

One national mechanism is particularly easy to miss: Vacant Building Credit.

 

Vacant Building Credit can reduce affordable housing contributions

 

Vacant Building Credit (VBC) is a national policy incentive for bringing qualifying vacant buildings back into lawful use or redeveloping them. Broadly, the existing gross floorspace is credited when the affordable housing contribution is calculated.

VBC affects affordable housing contributions only. It does not automatically remove other Section 106 obligations and it is not the same as the existing-floorspace rules used to calculate CIL.

The detail matters, particularly whether a building is vacant rather than abandoned, the evidence of its lawful use and vacancy history, and whether it was made vacant solely for redevelopment. See our dedicated guide to Vacant Building Credit for the calculation, evidence, exclusions and the West Berkshire case.

 

Can developer contributions be negotiated?

 

Yes, but there is an important distinction between negotiating the wording and timing of an obligation and simply arguing that a policy should not apply.

Useful issues to examine include:

• whether each requested obligation actually passes the three statutory tests
• whether the local policy relied upon is up to date and relevant to the proposal
• whether a Vacant Building Credit claim has been missed
• whether the contribution has been calculated correctly
• whether triggers and payment dates are realistic
• whether indexation has been applied from the correct date
• whether a monitoring fee is reasonable and proportionate
• whether particular site circumstances justify a viability assessment
• whether on-site provision or a commuted contribution is the proper mechanism

These matters are best addressed early. Leaving Section 106 negotiations until after the planning committee has resolved to grant permission can add months to the process.

 

Planning gain at appeal

 

Planning obligations can also matter at appeal. An appellant may provide a unilateral undertaking to secure obligations without needing the council to sign the deed.

The inspector still has to decide whether the obligations relied upon meet the statutory and policy tests. An obligation does not become relevant merely because the appellant has offered it.

 

Practical planning gain checklist

 

• Check the adopted development plan before assuming what contributions apply
• Identify whether the authority charges CIL and read the current charging schedule
• Separate CIL, Section 106, highway agreements and other statutory requirements
• Ask the council to identify the policy and calculation behind every requested contribution
• Check each Section 106 obligation against the three statutory tests
• Check whether existing vacant buildings qualify for Vacant Building Credit
• Do not confuse VBC with the separate CIL existing-floorspace deduction
• Check triggers, indexation, monitoring fees and any review mechanisms before signing
• Use viability only where there is a proper evidence-based reason to depart from policy
• Get the heads of terms clear early where a substantial agreement will be required

 

Where to go next

 

For the legal documents themselves, continue to our Planning Agreements and Obligations section and the dedicated Section 106 and unilateral undertaking guides. For the levy side, see our complete Community Infrastructure Levy section.

Planning gain describes what the development contributes through the planning process. The separate concept of planning uplift describes what happens to land value when its development prospects improve.

 

Planning gain law, policy and guidance

 

• Town and Country Planning Act 1990, section 106
• Community Infrastructure Levy Regulations 2010, regulation 122
• Planning Act 2008, Part 11: Community Infrastructure Levy
• Planning Practice Guidance: planning obligations, including the three tests, monitoring fees and commuted contributions
• National Planning Policy Framework, August 2026
• MHCLG letter on the current CIL regime, 25 June 2026

Developer contributions & planning agreements

 

Planning Gain Page Updated: 19th August 2026