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Part L Calculations

There are two calculation methods that are approved to demonstrate compliance with Part L (Energy & Carbon Emissions).

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Simplified Energy Model (SBEM) - Primarily used for non-domestic buildings such as offices, shops and schools. 

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Standard Assessment Procedure (SAP) - Used for domestic properties.

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Both methodologies evaluate a building's energy performance by considering several factors, including:

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• Construction materials

• Insulation levels

• Efficiency of heating, cooling and ventilation systems

• Efficiency of lighting solutions

• Building orientation and shape​

• Renewable Energy

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The primary aim of Part L is to reduce carbon emissions. More efficient buildings consume less energy which leads to a reduction in greenhouse gas emissions and a lower carbon footprint. 

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Efficiency also helps to reduce running costs which equates to reduced energy bills for homeowners and businesses. ​

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Part O Calculations

Part O calculations are needed to demonstrate  that a dwelling is not designed with an inherent summer overheating problem. The standard covers overheating in new residential buildings only. Part O was introduced in 2021 with the aim of encouraging the design and construction of buildings that limit unwanted solar gain during summer months. 

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Energy Statements

Energy Statements may be required by the local authority during the planning stage of a project. An Energy Statement will outline how a building will meet energy efficiency standards that may be set nationally or sometimes locally. The statement will cover all aspects of the energy efficiency plan for your building. 

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Building Physics, Passive Design & Natural Ventilation

Energy modelling and building simulation can provide influential information early in a project analysing how building form, function and physics of a development can achieve carbon and energy goals. 

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Simulation advice can extent to evaluating natural ventilation, mixed-code cooling strategies, thermal mass, nighttime cooling and other passive technologies. ​​

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Energy Strategy - Low & Zero Carbon Feasibility

Energy stratergies and LZC Feasibility studies establish the concept of how a development will be energised, heated and cooled efficiently and how LZC technologies can feed into that process productively. 

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BTP can provide consultancy, modelling and reporting to satisfy Energy Strategy and LZC Feasibility requirements for planning applications. 

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Thermal Comfort and Daylight Studies

These studies provde quantitative assessment to help design buildings that are both thermally comfortable and provide optimal daylight conditions for occupant wellbeing and energy reduction. ​​​

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Dynamic Simulation Modelling (DSM) Analysis

3-Dimensional Dynamic Simulation is one of the more sophisticated design tools we use to provide quantitative analysis and add rigour to the design process, to help shape and inform the building and optimise performance. ​

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This technology provides zonal and whole-building analysis, as well as information on energy consumption, carbon emissions, thermal performance, internal light levels and air movement. It is an essential tool in designing a well-optimised building. 

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