Navigating the intricacies of the London Plan’s energy and sustainability policies can be a daunting task for construction professionals operating within the capital’s boroughs.

With the emphasis on reducing carbon emissions and promoting sustainability, adherence to policies SI 2, SI 3, and SI 4 is essential for ensuring compliance and avoiding project delays.

What Are Policies SI 2, SI 3, and SI 4?

The following policies form the backbone of London’s approach to sustainable urban development.

Policy SI 2: Minimising Greenhouse Gas Emissions
This policy focuses on reducing carbon emissions through all stages of development. Key requirements include:

• Net-Zero Carbon Target: Major developments must achieve a net-zero carbon outcome.

• Energy Hierarchy:
  • Be Lean: Reduce energy use and demand with efficient building designs.
  • Be Clean: Use decentralised energy systems to supply energy efficiently.
  • Be Green: Maximise the use of renewable energy sources onsite.
  • Be Seen: Monitor and report operational energy performance.

Onsite carbon reductions must achieve 35% beyond Part L 2021 of the Building Regulations, with remaining emissions offset through contributions to borough-level carbon offset funds.

Policy SI 3: Energy Infrastructure
This policy promotes the development and integration of efficient energy systems. Requirements include:

• Developments in Heat Network Priority Areas (HNPAs) must assess the feasibility of connecting to existing or planned district heating networks.
• Where connection is not feasible, developers must design systems to be future-proofed for eventual connection to low-carbon heat networks.

Policy SI 4: Managing Heat Risk
This policy requires buildings to address the risk of overheating without relying on mechanical cooling. Key points include:

• Follow the Cooling Hierarchy:
  • Minimise Internal Heat Generation: Reduce equipment and lighting heat loads.
  • Reduce Solar Gains: Use shading, glazing, and orientation strategies.
  • Passive Ventilation: Maximise natural airflow.
  • Mechanical Ventilation: Use low-energy systems only when necessary.

• Dynamic Thermal Modelling (DTM) must be conducted to demonstrate compliance with CIBSE TM59 overheating criteria.

Why Are These Policies Required?

London faces unique challenges as a densely populated, urbanised city with ambitious sustainability goals. Policies SI 2, SI 3, and SI 4 address critical issues affecting the city’s energy performance, environmental footprint, and liveability.

1. Urban Heat Island Effects

London experiences higher temperatures compared to surrounding rural areas due to the urban heat island effect, where dense construction materials and limited green spaces trap heat. Policies like SI 4 aim to mitigate these risks by mandating passive cooling and reducing reliance on mechanical systems that exacerbate energy use.

2. Achieving Net-Zero Carbon by 2030

London has committed to being a net-zero carbon city by 2030, which will require a dramatic reduction in greenhouse gas emissions. Policy SI 2 ensures that new developments align with this vision by prioritising energy efficiency and renewable energy use.

3. Future-Proofing Energy Systems

The capital’s energy infrastructure must adapt to rising energy demands and climate change. Policy SI 3 focuses on integrating decentralised energy networks and designing buildings that can connect to future low carbon heating systems, reducing reliance on traditional energy sources.

4. Improving Air Quality

Policies SI 2 and SI 3 contribute to better air quality by promoting clean, efficient energy systems that reduce the city’s dependency on fossil fuels, directly addressing air pollution, which is a persistent issue in London.

5. Setting a Global Sustainability Benchmark

London is positioning itself as a leader in sustainable urban development. By enforcing these policies, the city is fostering innovative design practices that prioritise environmental responsibility and enhance its reputation on the global stage.

6. Protecting Occupant Health and Comfort

Overheating is becoming a growing concern in London’s new residential developments due to rising temperatures and increasing population density. Policy SI 4 ensures that overheating risks are addressed through dynamic modelling and passive measures, safeguarding the health and wellbeing of residents.

The London Plan Process

Navigating the planning journey for policies SI 2, SI 3, and SI 4 is a task that is best completed all at the same time. Whether for commercial or residential projects, each stage demands precise energy assessments and compliance strategies to ensure smooth planning approval.

Here’s what the process looks like, and the key services required at each step.

1. Pre-Planning: Understanding Requirements

Before submitting a planning, application or report for a building, developers must understand the specific requirements of the London Plan as they relate to their project.

• Energy Strategy: Understand the applicable policies and the proposed development context, as well as stakeholder intended outcomes, to predetermine the outcome as much as feasibly possible.
• Heat Network Feasibility Studies: For projects in Heat Network Priority Areas, assess the viability of connecting to district heating systems, or building an onsite system.
• Overheating Risk: Early investigation of potential pitfalls in building design that are bound to cause overheating risk.

2. Design Stage: Embedding Compliance

In this phase, the focus shifts to integrating sustainability and energy efficiency into the design to align with policies SI 2, SI 3, and SI 4.

• Building Optimisation: Improve insulation, airtightness, and fixed services specifications to reduce energy demand (Policy SI 2).
• Decentralised Energy Integration: If feasible, work out and report on logistics for network connection, present or future.
• Renewable Energy System Design: Incorporate onsite renewables, such as solar PV, to meet the 35% carbon reduction target.
• Dynamic Thermal Modelling: Simulate building performance to mitigate overheating risks and ensure occupant comfort (Policy SI 4).

3. Planning Submission: Demonstrating Compliance

This step involves creating and submitting the required documentation to borough planners to demonstrate adherence to the London Plan.

• Energy Statements: Comprehensive reports showing how the development meets the Energy Hierarchy,heat network, and carbon reduction targets (Policy SI 2).
• Overheating Reports: Present dynamic thermal modelling results to demonstrate compliance with Part O and CIBSE TM59 overheating criteria (Policy SI 4).

4. Post-Approval: Implementation and Monitoring

Once planning approval is obtained, the focus shifts to ensuring that the approved strategies are implemented during construction and verified post-completion.

• Construction Stage Energy Assessments: Verify that the building fabric, renewables, and energy systems match the approved designs.
• Post-Construction Reporting: Monitor and report on energy performance as part of the Be Seen step in Policy SI 2.
• Heat Network Connection Support: Facilitate the connection of decentralised energy systems to district heating networks.

Commercial vs. Residential Applications

• Commercial Projects: Often require more complex solutions, such as large-scale renewable systems and robust connections to district heating networks. Detailed dynamic modelling is essential for office buildings, retail spaces, and mixed-use developments in urban heat islands.
• Residential Projects: Focus on improving occupant comfort and meeting strict overheating criteria. These projects typically prioritise passive cooling strategies, high-performance building fabrics, and onsite renewable energy integration.

Navigating the London Plan process requires careful planning, specialised expertise, and precise documentation. Whether for commercial or residential projects, engaging experienced professionals ensures compliance with Policies SI 2, SI 3, and SI 4, minimises delays, and enhances the sustainability and performance of your development. Let Energy Digest guide you through the planning journey with tailored solutions for every stage.

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