At Eternal Engineering, we are committed to delivering sustainable building solutions that meet and exceed the stringent energy efficiency requirements set forth in Building Regulations Part L across the UK and Ireland. Our expertise ensures that your projects achieve full compliance while contributing to a greener, more sustainable future.

UK Part L Compliance

Part L of the UK Building Regulations focuses on the conservation of fuel and power, ensuring that buildings are designed and constructed to be energy efficient. We ensure full compliance with Part L requirements for all new builds and major renovations.

Our services include:

• SAP and SBEM calculations for regulatory approval
• U-value assessments and thermal performance analysis
• Air tightness testing and certification
• Energy Performance Certificate (EPC) provision
• Building Control submission and compliance documentation

We help reduce carbon emissions, lower energy costs, and meet the mandatory energy efficiency standards required across England, Wales, Scotland, and Northern Ireland.

Ireland Part L Compliance

Part L of Ireland’s Building Regulations sets energy performance standards aligned with the Nearly Zero Energy Buildings (NZEB) directive. All new buildings must achieve high energy efficiency with significant renewable energy integration.

Our services include:

• DEAP and NEAP energy assessments
• Building Energy Rating (BER) certification (minimum A2 for new dwellings)
• Renewable energy integration design
• Air tightness testing and compliance verification
• Part L compliance documentation and certification

We ensure your project meets Ireland’s stringent energy standards, achieves excellent BER ratings, and incorporates sustainable design principles for reduced environmental impact.

ENE 01 – Reduction of Energy Use and Carbon Emissions

ENE 01 aims to recognize and encourage buildings designed to minimize operational energy demand, consumption and CO2 emissions. We provide comprehensive support to maximize your credits through detailed energy performance analysis.

Our services include:

• BRUKL/BRIRL compliance output for Building Regulations and BREEAM assessment
• Dynamic simulation modeling for accurate energy predictions
• Analysis of operational energy demand, primary energy consumption, and CO2 emissions
• Passive design analysis to demonstrate energy demand reduction.

ENE 04 – Low Carbon Design (Passive Design Analysis)

ENE 04 encourages the adoption of design measures which reduce building energy demand and associated carbon emissions. The passive design credit recognizes buildings that incorporate effective natural design strategies.

Our services include:

• Passive design analysis comparing building performance with and without passive measures
• Standard building baseline modeling for comparison
• Assessment of building orientation, glazing distribution, and natural ventilation strategies
• Thermal mass and shading analysis

HEA 04 – Thermal Comfort

HEA 04 ensures that appropriate thermal comfort levels are achieved through design, and controls are selected to maintain a thermally comfortable environment for occupants. This credit is essential for building performance and occupant wellbeing.

Our services include:

• PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) analysis according to ISO 7730:2005
• Current climate thermal comfort assessment using CIBSE Design Summer Year (DSY) weather files
• Future climate change scenario modeling (50th percentile projections)
• Overheating risk analysis and mitigation recommendations

Early Stage: Simple Box Energy Modeling

Concept Design Support

During the early design phase, we use simplified box modeling with parametric simulation to quickly evaluate design alternatives and inform critical decisions about building form, orientation, and envelope strategies.

Our services include:

LEED points feasibility assessment

Parametric box modeling for rapid design iteration

Building orientation and massing studies

Window-to-wall ratio optimization

Envelope performance analysis (U-values, glazing types)

Passive design strategy evaluation

Preliminary energy performance estimates

Detailed Stage: Apache HVAC Energy Modeling

Whole Building Performance Rating (ASHRAE 90.1 Appendix G)

For LEED compliance and final certification, we provide detailed whole-building energy modeling using Apache HVAC simulation software following ASHRAE 90.1 Appendix G Performance Rating Method.

Our services include:

• Baseline building model creation per ASHRAE 90.1-2016 or 2019 requirements
• Proposed building model with all energy conservation measures
• Detailed HVAC system modeling including all plant equipment, air systems, and controls
• Four-orientation baseline model averaging (as required by Appendix G)
• Performance Cost Index (PCI) and Greenhouse Gas (GHG) emissions calculations
• LEED EA Prerequisite 2 (Minimum Energy Performance) compliance
• LEED EA Credit: Optimize Energy Performance points calculation
• Comprehensive LEED Online submission documentation
• Quality assurance reviews and input/output verification

Apache HVAC capabilities include:

• Advanced HVAC system modeling (VAV, CAV, chilled beams, radiant systems, VRF, etc.)
• Detailed plant equipment simulation (chillers, boilers, cooling towers, heat pumps)
• Complex control strategies and sequences of operation
• Renewable energy systems integration (solar PV, solar thermal)
• Service hot water systems with heat recovery
• Exceptional calculation methods for non-standard technologies