What we offer.

Part L Calculations: SAP & SBEM

Part L of the Building Regulations sets requirements for the conservation of fuel and power in buildings. Energy calculations are used to assess whether proposed developments meet the applicable energy performance standards.
We provide SAP and SBEM calculations to support compliance for residential and commercial developments, helping design teams assess energy efficiency and identify improvements where required.

SAP Calculations

The Standard Assessment Procedure (SAP) is the methodology used to assess the energy performance of dwellings under the relevant regulatory framework.
SAP calculations consider factors such as insulation, heating systems, ventilation, glazing and renewable energy technologies to evaluate a property’s predicted energy performance.
We support residential developments with design-stage and as-built calculations, helping demonstrate compliance with Part L and providing the information required for Energy Performance Certificates.

SBEM Calculations

The Simplified Building Energy Model (SBEM) is used to assess the energy performance of many non-domestic buildings, including offices, retail premises and commercial developments.
SBEM calculations evaluate the building fabric, heating, cooling, ventilation and lighting systems to determine predicted energy performance and carbon emissions under standardised conditions.
We undertake SBEM assessments to support Part L compliance, identify opportunities for energy efficiency improvements and provide the calculations required for relevant building certification.

Part O Overheating Calculations

Part O of the Building Regulations addresses overheating risk in new residential buildings in England.
We undertake overheating assessments to evaluate whether proposed dwellings are likely to experience excessive internal temperatures and to support compliance with the relevant requirements.
Our assessments consider factors such as glazing, solar gains, ventilation, building orientation and the surrounding environment.
Where necessary, we help design teams explore practical measures to reduce overheating risk, including improved shading, ventilation strategies and adjustments to glazing specifications.

Energy Performance Certificates (EPCs)

Energy Performance Certificates provide an assessment of a property’s energy efficiency, using a rating from A to G.
EPCs are required in many circumstances when buildings are constructed, sold or rented, subject to applicable exemptions.
We provide domestic and non-domestic EPC services to help property owners, developers and businesses understand the energy performance of their buildings and meet relevant certification requirements.
Our assessments provide an energy efficiency rating and recommendations for potential improvements, helping clients make informed decisions about their properties.

EPC Analysis & Optioneering

Improving a building’s EPC rating can require a careful assessment of its existing performance and the potential benefits of different upgrades.
We provide EPC analysis and optioneering services to help building owners and asset managers identify suitable energy efficiency improvements.
Our assessments can consider building fabric upgrades, heating and cooling systems, lighting, ventilation and renewable energy technologies.
By comparing potential improvement measures, we help clients understand how different interventions may influence their EPC rating and support informed investment decisions.

Air Pressure Testing

Air pressure testing measures the airtightness of a building and helps identify uncontrolled air leakage through the building envelope.
Excessive air leakage can increase heat loss, energy consumption and the demand placed on heating and cooling systems.
We support air pressure testing for residential and commercial developments, helping project teams assess building airtightness and demonstrate compliance with applicable Part L requirements.
Testing can also help identify areas where improvements to sealing and construction detailing may be necessary.

Thermal Bridging Analysis

Thermal bridging occurs where heat transfers more readily through particular elements or junctions within a building’s construction.
Poorly addressed thermal bridges can contribute to heat loss, increased energy consumption and a greater risk of surface condensation and mould growth.
We undertake thermal bridging analysis to assess heat transfer through building junctions, helping design teams understand their impact on overall thermal performance.
Our assessments support improved construction detailing, more accurate energy calculations and the development of efficient building envelopes.

Display Energy Certificates (DECs)

Display Energy Certificates provide information about the actual operational energy performance of qualifying public buildings.
Unlike Energy Performance Certificates, which assess energy efficiency using standardised assumptions, DECs reflect recorded energy consumption during building operation.
We provide Display Energy Certificate services to support eligible public buildings in meeting their statutory requirements.
These assessments help building operators understand energy performance and identify opportunities to improve efficiency.

Part G Water Efficiency Calculations

Part G of the Building Regulations includes requirements relating to water efficiency in new dwellings in England.
Water efficiency calculations assess the estimated daily consumption of potable water based on the specification of fittings and appliances, including taps, showers, toilets and baths.
We undertake Part G water efficiency calculations to help residential developments demonstrate compliance with applicable water consumption limits.
Our assessments support design teams in selecting suitable water-efficient fittings and achieving the required performance standards without compromising practicality or occupant comfort.

Supporting Building Compliance from Design to Completion

Building compliance is most effective when regulatory requirements are considered throughout the design and construction process.
RA Sustainability works with project teams to identify assessment requirements, review building performance and provide the technical information needed to support regulatory submissions.
Whether you require SAP or SBEM calculations, overheating assessments, energy certification or specialist building performance testing, we can help you understand the requirements relevant to your project.

Contact RA Sustainability to discuss your building compliance requirements and find out how we can support your development.