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Understanding SBEM calculations

SBEM stands for Simplified Building Energy Model.

It’s essentially a tool used by those who design and build buildings (like housebuilders, architects and property developers) to make sure they meet energy rules for non-domestic buildings. It looks at how much energy a building will use and helps make decisions to use less energy and pollute less. This is crucial for meeting building regulations and for making buildings that are good for the environment as well as less costly to heat and cool. 

SBEM calculations, therefore, are a method used to evaluate the energy efficiency of commercial buildings. SBEM calculates the monthly energy use and carbon emissions of a building based on its construction, geometry, use, lighting, heating, and cooling systems.

The purpose of SBEM calculations 

The primary goal of SBEM calculations is to ensure that building designs comply with energy efficiency requirements set out in building regulations. These calculations help in predicting the environmental impact and energy performance of buildings, guiding the design towards more sustainable and efficient solutions.

How SBEM calculations are performed

Conducting an SBEM calculation requires a qualified professional and involves several steps, requiring detailed information about the property such as:

Building Geometry 

This aspect covers the physical dimensions and spatial configuration of the building, including its height, width, and depth. It also takes into account the building’s orientation, which can significantly influence its thermal performance by affecting how much sunlight it receives at different times of the day and year. The shape of the building, whether it’s compact or spread out, can also impact its energy efficiency by altering the surface area exposed to the external environment.

Construction Materials

This component involves specifying the materials used in constructing the building’s envelope, such as walls, roof, and floors. It includes information on the thermal properties of these materials, such as their insulation levels and ability to retain or reflect heat. The choice of materials can significantly affect the building’s overall thermal efficiency, influencing how well the building maintains its internal temperature and reducing the need for additional heating or cooling.

Heating, Ventilation, and Air Conditioning (HVAC) Systems

This section details the building’s HVAC systems, focusing on the types of heating, cooling, and ventilation equipment installed, such as boilers, air conditioners, and ventilation units. It also covers the systems’ energy efficiency ratings and the types of controls used to operate them, including thermostats, timers, and automated building management systems. These specifications are crucial for understanding how the building’s climate is managed and how energy-efficient the HVAC systems are in maintaining comfortable indoor conditions.

Lighting Systems

This aspect encompasses the design and layout of the building’s lighting system, including the types of light fixtures used (e.g., LED, fluorescent) and their distribution throughout the building. It also covers the control systems in place, such as motion sensors, dimmers, and daylight harvesting systems, which adjust the lighting based on occupancy and natural light availability. These details help assess the energy efficiency of the lighting system and its impact on the building’s overall energy consumption.

Building Use

This section provides insight into the intended function of the building, such as office space, retail, educational facility, or industrial use. It examines how the building’s purpose influences the number of people using the building at any given time, the types of equipment and machinery that will be in operation, and the typical hours during which the building will be active. These factors play a crucial role in determining the building’s energy needs and help in tailoring the SBEM calculations to accurately reflect the building’s real-world energy usage patterns.

By inputting this data into the specialist SBEM software, building professionals can generate a detailed report that assesses the building’s energy performance. This report is essential for demonstrating compliance with building regulations and for making informed decisions to improve the building’s energy efficiency.

Types of buildings requiring SBEM Calculations

SBEM calculations are necessary for a variety of projects, particularly those involving non-domestic buildings. This includes new constructions, extensions, and refurbishments where the building’s heating, cooling, or ventilation systems are changed. Commercial spaces like offices, retail stores, and warehouses, as well as educational institutions, healthcare facilities, and industrial buildings, typically fall under this category.

Examples of buildings requiring SBEM Assessments:

At what phase(s) are SBEM calculations needed?

SBEM calculations are crucial at several points in a building’s lifecycle. During the initial design phase, they help in shaping a building’s architectural and mechanical systems to ensure energy efficiency. 

Before construction begins, these calculations are used to validate the design against regulatory requirements. Upon completion, SBEM assessments may be revisited to certify the building’s compliance with the intended energy specifications, especially if any modifications were made during construction.

SBEM calculations are also utilised in existing buildings to produce their Energy Performance Certificate (EPC). An EPC is a standardised document that provides information on the energy efficiency of a building. It rates the energy performance of a building on a scale from A to G, with A being the most energy-efficient and G being the least. 

SBEM calculations and Part L compliance

SBEM calculations are crucial for demonstrating compliance with Part L of the Building Regulations in England, which focus on the conservation of fuel and power in new and existing buildings. These regulations set specific targets for energy performance and carbon emissions, and SBEM calculations provide the necessary documentation to prove that a building design meets these targets.

Compliance with Part L is a legal requirement, and SBEM calculations are the standard method for non-domestic buildings to demonstrate this compliance, ensuring that they contribute to national energy efficiency and carbon reduction goals.

How to obtain a SBEM calculation?

SBEM calculations must be carried out by qualified professionals who are accredited Energy Assessors – like Building Energy Experts. That means we have undergone specific training and certification to understand building energy modelling and the regulations surrounding building energy performance. Accreditation schemes ensure that assessors are competent and maintain their knowledge up to date with continuous professional development.

Here’s our step-by-step process of obtaining an SBEM calculation for your building:

  1. Initial assessment
    The process begins with an initial assessment, where the building’s design and specifications are reviewed to understand its energy requirements.
  2. Data Collection
    Detailed information about the building’s geometry, construction materials, HVAC systems, lighting, and intended use is collected.
  3. Modelling
    Using the specialist SBEM software, the collected data is input to create a model of the building. This model simulates the building’s energy performance.
  4. Analysis
    The specialist SBEM software analyses the model to calculate the building’s energy efficiency and carbon emissions.
  5. Testing
    The results of airtightness testing can be used as input data in SBEM calculations to provide a more accurate representation of the building’s energy performance.
  6. Optimisation
    If necessary, the design can be adjusted and re-analysed to improve energy efficiency and ensure compliance with regulations.
  7. Finalisation
    Once the building design meets the required standards, the final SBEM calculations are prepared and handed over to the key project stakeholders.

Documentation & Reports

The SBEM calculations culminate in the production of two key documents.

Energy Performance Certificate (EPC) 

This document rates the building’s energy efficiency from A (most efficient) to G (least efficient) and is required for all new, sold, or rented buildings.

BRUKL Report

The Building Regulations UK Part L (BRUKL) report is generated from the SBEM calculations and is submitted to building control bodies to demonstrate compliance with Part L of the Building Regulations.

These documents are vital because they not only ensure regulatory compliance but also provide valuable insights into the building’s energy performance, guiding future energy-saving measures and sustainability practices.

Working with Building Energy Experts

If you’re building a new commercial property or renovating an existing one, don’t navigate the complexities of SBEM alone – let our experts guide you though the process. Our team of accredited assessors can ensure that your building design meets energy efficiency standards and minimises environmental impact, all while keeping your project on track.

Contact us today for a free SBEM calculation consultation – we’ll answer your questions and help you to achieve a sustainable and cost-effective building solution.

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