Building Regulations Part L Solar PV SAP 10 Guide

Key Takeaways

• Building Regulations Approved Document L establishes legal energy efficiency standards for dwellings and commercial buildings in England.
• Integrating rooftop solar PV directly reduces calculated Target Primary Energy Rates (TPER) and Target Emission Rates (TER) under SAP 10.
• The Boiler Upgrade Scheme (BUS) provides capital support to replace fossil fuel heating systems with low-carbon heat pumps.
• Grants offer £7,500 towards an air source heat pump or ground source heat pump.
• Individual systems are capped at 45kWth capacity, with hybrid gas-electric systems ineligible for grant support.
• Funding is restricted to one grant per property across eligible domestic and commercial premises.

Approved Document L Framework and Standards

The energy conservation of residential buildings in England is governed by strict statutory instruments:

• Regulatory Scope: Building regulation in England setting standards for the energy performance of new and existing buildings.
• Dwelling Standards: Enforced under Approved Document L, Conservation of fuel and power, Volume 1: Dwellings, 2021 edition incorporating 2023 amendments.
• Under the Standard Assessment Procedure (SAP 10), on-site solar generation offsets electricity import figures, ensuring new homes achieve compliance with tightening primary energy targets.

Boiler Upgrade Scheme: Capital Support

To transition away from fossil fuel reliance, property owners can access government grant funding:

• Scheme Mandate: Through the Boiler Upgrade Scheme, you could get a grant to cover part of the cost of replacing fossil fuel heating systems with a heat pump or biomass boiler.
• Premises Scope: You can use the grant to replace a heating system in your home or a building used for your business.
• Geographic Availability: This scheme is open to people in England and Wales.
• One Grant Rule: You can get one grant per property.

Technology Grants and Capacity Limits

The scheme defines precise financial support tiers for approved renewable technologies:

• Air Source Heat Pumps: Grants provide £7,500 towards an air source heat pump (sometimes called an air-to-water heat pump).
• Ground Source Heat Pumps: Allocates £7,500 towards a ground source heat pump (including water source heat pumps and those on shared ground loops).
• Biomass Boilers: Offers £5,000 towards a biomass boiler.
• Air-to-Air Systems: Grants provide £2,500 towards an air-to-air heat pump.
• Individual Capacity Limit: The maximum capacity is 45kWth for individual systems.
• Hybrid Exclusion: You cannot get a grant for a hybrid heat pump system (for example a combination of gas boiler and air source heat pump).