Approved Document L covers various aspects of energy efficiency in new dwellings, including:
1. Limiting Heat Loss: It sets standards for the maximum allowable heat loss through the fabric of a dwelling, including walls, floors, roofs, windows, and doors. This is achieved by specifying minimum insulation levels and airtightness requirements.
2. Energy Efficiency Measures: Approved Document L outlines energy-efficient measures that must be incorporated into new dwellings, such as efficient heating systems (e.g., condensing boilers), renewable energy sources (e.g., solar panels), and improved ventilation systems.
3. Overall Energy Performance: The document sets targets for the overall energy performance of new dwellings. It requires that new dwellings achieve a certain level of energy efficiency, as measured by the Dwelling Emission Rate (DER) or Target Carbon Dioxide Emission Rate (TER). The DER/TER is a measure of the amount of carbon dioxide emitted by the dwelling per square meter of floor area per year.
4. Compliance Demonstration: Approved Document L provides methods and procedures for demonstrating compliance with the energy efficiency requirements. This may involve calculations, simulations, or other approved methods to show that the proposed design meets the specified standards.
Overall, Approved Document L aims to promote energy conservation and reduce carbon emissions in new dwellings by setting minimum energy efficiency standards and encouraging the adoption of energy-efficient technologies and practices. These regulations contribute to the UK government's goals for sustainable building practices and reducing the environmental impact of new construction.