The TM54 Assessment methodology is essential for accurately calculating predicted in-operation energy use in buildings.
By considering variability and uncertainty in input data, it provides upper and lower estimates, making it a robust alternative to the Simplified Building Energy Model (SBEM). Unlike SBEM, which is primarily for compliance checks, the TM54 offers reliable predictions of operational performance.
What is TM54?
TM54, published by the Chartered Institution of Building Services Engineers (CIBSE), addresses the critical issue of the performance gap in buildings. This gap highlights that many buildings do not perform as their designers intended, impacting both energy costs and emissions.
Causes of the Performance Gap
The main reason for the performance gap is that modern compliance methods often overlook significant energy uses. For example, energy consumed by lifts, escalators, catering facilities, and server rooms is frequently unaccounted for.
In a notable case study at the National Trust HQ in Swindon, it was revealed that 60% of the total energy use came from the server room and catering, even though these areas occupied only 3% of the floor space. This oversight nearly doubled the operational energy use compared to initial design estimates.
How TM54 Enhances Energy Performance Predictions
The TM54 Assessment provides building designers and owners with clear guidance on evaluating operational energy use more comprehensively during the design stage. It facilitates better accounting for factors such as operating hours and occupancy, tailored to the building’s intended use.
Comprehensive Energy Use Estimation
TM54 accounts for more detailed assessment of operational energy at the design stage
TM54 covers various aspects of operational energy, including:
- Lighting
- Heating, Ventilation, and Air Conditioning (HVAC)
- Hot Water Provision
- Lifts and Escalators
- Small Power Loads
- Catering and Server Rooms
- Other Plant and Equipment
By including these critical elements, TM54 enables a more accurate estimation of the operational energy required for a building.
How We Support TM54 Evaluation
At BE we specialise in assisting M&E teams, architects, and contractors in accurately predicting the energy performance of their projects. Our approach incorporates Dynamic Simulation Modelling (DSM) tools and a consultative strategy to maximise value for all stakeholders.
TM54 assessment is also an integral part of Whole Life Carbon Assessments – these are often required by planners, especially those applications within the London boroughs.
For more information on TM54: Evaluating Operational Energy Performance of Buildings at Design Stage, please visit the CIBSE website.
Contact Us for TM54 Assessment Support
Would you like to discuss your project further?
Call us on 0330 055 34 05 or email be@buildenergy.co.uk– we’re here to help!