What Is a Section 106 Agreement? A Complete Guide for Land Buyers

What Is a Section 106 Agreement?

If you're planning to buy land for development in the UK, you'll likely encounter a Section 106 agreement (often abbreviated to S106). These legally binding agreements between developers and local planning authorities can add substantial costs to your project and significantly influence your development timeline — yet many first-time land buyers underestimate their impact.

A Section 106 agreement, named after Section 106 of the Town and Country Planning Act 1990, is a planning obligation that makes a development proposal acceptable in planning terms when it wouldn't otherwise be permitted. In practical terms, it's a contract that requires developers to provide community benefits or mitigate the negative impacts of their development.

Understanding Section 106 agreements is crucial before purchasing development land. According to the Ministry of Housing, Communities and Local Government, S106 contributions totalled over £7.4 billion in England during 2023-2024, demonstrating just how significant these obligations have become in the planning system.

How Section 106 Agreements Work

When you submit a planning application for a development that will impact local infrastructure or community facilities, the local planning authority may require you to enter into a Section 106 agreement before granting permission. These agreements are negotiated on a case-by-case basis, taking into account the specific impacts of your proposed development.

The agreement becomes a legal charge against the land itself, which means the obligations transfer with the property if you sell before completing the development. This is a critical point for land buyers: you inherit any existing S106 obligations when you purchase the land.

Types of Planning Obligations

Section 106 agreements typically fall into three categories:

Financial contributions: Direct payments to the local authority to fund infrastructure improvements, such as school expansions, healthcare facilities, highway improvements, or public transport enhancements. These contributions can range from tens of thousands to millions of pounds depending on the development size.

Affordable housing requirements: For residential developments, local planning authorities commonly require a percentage of units to be sold or rented at below-market rates. In 2026, many councils require between 20% and 40% affordable housing on developments of 10 or more units, though thresholds and percentages vary significantly by location.

In-kind obligations: Requirements to provide specific facilities or improvements directly, such as building a community centre, creating public open space, or constructing new road access.

When Are Section 106 Agreements Required?

Not every development will trigger a Section 106 agreement. Local planning authorities apply three key tests (established by the Community Infrastructure Levy Regulations 2010) to determine whether planning obligations are justified:

1. Necessary to make the development acceptable in planning terms: The obligation must directly address a planning concern that would otherwise prevent approval

2. Directly related to the development: There must be a clear connection between the proposed development and the obligation required

3. Fairly and reasonably related in scale and kind: The obligation must be proportionate to the development's impact

Larger developments typically face more substantial S106 requirements. Residential schemes of 10 or more dwellings almost always involve planning obligations, particularly for affordable housing. However, even smaller developments can trigger obligations if they impact local infrastructure or services.

Commercial and industrial developments may require contributions toward transport improvements, particularly if they'll generate significant traffic. Mixed-use schemes often face the most complex S106 negotiations, addressing both residential and commercial impacts.

Section 106 vs Community Infrastructure Levy (CIL)

Many local authorities now operate both Section 106 agreements and the Community Infrastructure Levy (CIL), which can cause confusion for land buyers. While both fund infrastructure, they work differently:

CIL is a standardised charge based on the floorspace of your development, calculated using published rates per square metre. It's non-negotiable and applies to most new builds and extensions. CIL funding goes into a general pot for infrastructure improvements across the authority area.

Section 106 agreements are negotiated on a project-specific basis and directly address the impacts of your particular development. They're used for site-specific requirements that CIL doesn't cover, particularly affordable housing provision.

In areas with an adopted CIL charging schedule, Section 106 agreements have become more focused on affordable housing and site-specific infrastructure that directly serves the development. Understanding whether your target local authority operates CIL is essential when assessing land values and development viability.

How Section 106 Affects Land Value and Development Costs

Section 106 obligations have a direct impact on land values. Experienced developers factor expected S106 costs into their residual land valuations, which means land with onerous planning obligations should be priced lower than land without such constraints.

When purchasing development land, you must conduct thorough due diligence on potential S106 requirements:

Research local planning policy: Review the local plan's policies on affordable housing percentages, infrastructure contributions, and other planning obligations. Most councils publish supplementary planning documents (SPDs) detailing their approach to S106.

Examine comparable developments: Look at recently approved planning applications for similar developments in the area. Planning registers are publicly accessible and include copies of Section 106 agreements, revealing what contributions were required.

Engage pre-application advice: Before purchasing land, consider paying for pre-application advice from the planning authority. This can provide clarity on likely S106 requirements and help you assess development viability.

Budget realistically: S106 costs can represent 10-30% of development value in some areas, particularly in London and the South East. Underestimating these costs is a common mistake that can render developments financially unviable.

Regional Variations

Section 106 requirements vary significantly across the UK:

England: Section 106 operates most extensively here, with significant variations between authorities. London boroughs typically impose the highest affordable housing requirements (often 35-50%), while some northern authorities may require 10-20%.

Scotland: Uses Section 75 agreements (Planning (Scotland) Act 1997) which function similarly but with different legal frameworks and terminology.

Wales: Follows the English S106 system but with distinct policy guidance and typically lower affordable housing percentages.

Northern Ireland: Uses Article 40 agreements (Planning Act Northern Ireland 2011) as the equivalent mechanism.

For those exploring land opportunities across different counties, understanding these regional differences is crucial for accurate financial modelling.

Negotiating Section 106 Agreements

While some S106 requirements are set in policy, there's often room for negotiation, particularly on larger or more complex schemes. Developers can argue that planning obligations would make their scheme financially unviable by submitting a viability appraisal.

Viability appraisals are detailed financial assessments demonstrating the development's expected costs and revenues. If you can prove that meeting full S106 requirements would prevent the scheme from generating a reasonable profit, the planning authority may reduce the obligations.

However, viability negotiations are becoming more sophisticated and scrutinised. Many councils now employ specialist viability consultants to review developer submissions, and the National Planning Policy Framework emphasises that land value should reflect policy requirements, including S106.

Key negotiation strategies include:

Submit robust evidence: Poor quality viability appraisals waste time and damage credibility. Engage qualified surveyors experienced in development viability.

Consider phasing: For large developments, negotiate phased S106 contributions aligned with development completion, improving cashflow.

Explore alternative provision: If direct provision of affordable housing isn't viable, some authorities accept commuted sums (cash payments) instead, though this is increasingly discouraged.

Build early relationships: Engaging positively with planning officers from the outset often leads to more productive negotiations than adversarial approaches.

Common Section 106 Pitfalls for Land Buyers

Many land buyers, particularly those new to development, make costly mistakes with Section 106 agreements:

Assuming existing planning permission is straightforward: Just because land has planning permission doesn't mean S106 obligations are fully discharged. Review the agreement carefully to understand outstanding requirements and trigger points.

Overlooking trigger clauses: Section 106 agreements contain specific triggers determining when obligations must be met (e.g., before occupation of the 50th dwelling). Missing these triggers can halt your development.

Ignoring monitoring fees: Local authorities charge annual monitoring fees for managing S106 agreements, typically £500-£3,000 per year. These continue until all obligations are fulfilled.

Underestimating affordable housing impact: Providing 30% affordable housing doesn't just reduce sellable units — it affects development layout, marketing, and management. Build these considerations into your planning from the start.

Failing to check modification possibilities: Some historic S106 agreements can be modified or discharged under Section 106A if circumstances have changed. However, this requires formal application and isn't guaranteed.

Due Diligence Checklist for Land Buyers

Before purchasing land that may require a Section 106 agreement, complete this due diligence:

1. Obtain local planning policy documents: Download the local plan and any SPDs on planning obligations and affordable housing

2. Check for existing agreements: If purchasing land with planning permission, obtain copies of all Section 106 agreements from the seller and verify their status with the Land Registry

3. Research comparable schemes: Review recent planning applications and their S106 agreements on the planning register

4. Calculate preliminary costs: Model different S106 scenarios (e.g., 20%, 30%, and 40% affordable housing) to test development viability

5. Assess CIL liability: Check if the authority has adopted CIL and calculate likely charges using their published rates

6. Consider professional advice: Engage a planning consultant for pre-application discussions before completing your land purchase

7. Review title documents carefully: Ensure your solicitor examines any restrictive covenants or previous planning obligations that might affect development

These checks should form part of your broader due diligence process when buying land in the UK.

Section 106 and Future Planning Reform

The planning system continues to evolve, and Section 106 is subject to ongoing reform discussions. The government has periodically proposed replacing S106 entirely with an expanded Infrastructure Levy, though implementation timelines remain uncertain as of 2026.

Proposed changes aim to make the system more transparent and predictable, potentially setting mandatory rates rather than negotiated agreements. However, until reforms are implemented, the current S106 system remains firmly in place.

Stay informed about planning policy changes by monitoring:

• Ministry of Housing, Communities and Local Government announcements
• Local authority planning policy consultations
• Professional bodies like the Royal Town Planning Institute (RTPI)
• Planning law updates from organisations like the Planning Inspectorate

Understanding the Legal Framework

Section 106 agreements are legally binding contracts registered as local land charges. This means they:

• Bind future owners of the land
• Are enforceable by the local planning authority
• Can only be modified or discharged through formal legal processes
• Appear on official searches during property transactions

The agreements are drafted by solicitors and must be signed as deeds before planning permission is granted. They typically include:

• Detailed obligations and trigger points
• Definitions of affordable housing or other requirements
• Payment schedules for financial contributions
• Monitoring and enforcement provisions
• Indexation clauses (how contributions increase over time)

Always have an experienced property solicitor review Section 106 agreements before completing a land purchase. The legal complexities can have significant financial implications if misunderstood.

Making Section 106 Work for Your Development

While Section 106 agreements add cost and complexity, they also serve a legitimate purpose in creating sustainable, well-integrated developments. Viewing S106 positively can actually benefit your project:

Better infrastructure: Contributions toward schools, healthcare, and transport make your development more attractive to buyers

Community integration: Providing affordable housing and community facilities reduces local opposition and creates mixed, balanced communities

Planning approval: Meeting S106 requirements removes a major obstacle to gaining consent, avoiding appeals and delays

Reputational benefits: Developers who engage constructively with planning obligations build better relationships with local authorities and communities

The key is accurate budgeting and realistic expectations from the outset. Build S106 costs into your land acquisition price rather than treating them as unexpected extras.

Conclusion

Section 106 agreements are an integral part of the UK planning system that every land buyer must understand. Whether you're purchasing a small plot for a single dwelling or a large site for major development, planning obligations will likely affect your project's viability and timeline.

The critical lessons for land buyers are:

• Factor S106 costs into land valuations from the start
• Conduct thorough due diligence on local planning policies
• Engage early with planning authorities to understand requirements
• Build realistic contingency into your budget
• Seek professional advice on complex agreements

By understanding how Section 106 agreements work and planning accordingly, you can avoid costly surprises and develop viable, sustainable projects that benefit both you and the local community.

For detailed guidance on understanding planning permission and navigating the broader aspects of land acquisition, explore our comprehensive guides. If you're ready to explore development opportunities, browse land by location or get a free land valuation to understand potential values in your target area.

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Need expert guidance on land with planning obligations? Understanding Section 106 implications is crucial for successful land investment. Get a free professional land valuation to assess development viability, or explore our complete buying guide for comprehensive advice on purchasing development land in the UK.