How do MEP services increase energy efficiency in buildings?
Tom Hawkins | January 27, 2025
HVAC systems in a commercial building will typically account for 40% of its total energy use. Lighting will typically account for a further 15%. Optimising your MEP systems is therefore critical for reducing energy consumption, and MEP refit projects for decarbonisation are increasingly common.
Benefits of optimising MEP systems
Increasing the energy efficiency of the building will have the following benefits for your clients:
- Reducing energy usage, leading to cost savings
- Reducing emissions, meeting increasingly stringent government regulations
- Improving system performance, leading to better working environments for building users
Expert MEP services can support two different types of decarbonisation: operating carbon reduction and embodied carbon reduction.
Operating carbon reduction is probably closest to what most people imagine when they want to improve energy efficiency. This refers to reducing the energy used by the building on a day-to-day basis.
Embodied carbon reduction is now increasing in prominence. This means reducing the carbon footprint of a building’s construction (including transport of materials), its maintenance and its demolition.
In this article we will discuss how MEP services help to reduce operating carbon, which applies to both new buildings and existing buildings.
Main targets for MEP efficiency gains
HVAC efficiency
As HVAC systems account for 40% of energy use for a building, they are an obvious place to start. In addition, despite the costs of re-fitting HVAC systems, it is likely clients will make significant long-term savings on utility bills, therefore offsetting the upfront expenditure.
A good first step is to conduct an energy audit and use BIM (Building Information Modelling) to simulate HVAC performance and analyse energy usage in the building.
This information is then used to identify opportunities to increase energy efficiency by selecting the ideal equipment sizes and optimise layout.
For example, MultiCAD’s BIM services include planning duct and pipe sizes along with estimation of the resulting heat load to create an accurate, digital simulation. Doing this before materials are even ordered allows our clients to spot opportunities for energy efficiency gains that would otherwise be missed.
This highly accurate, highly detailed and highly accessible approach ensures you don’t miss chances to optimise the system’s energy efficiency. These are some of the opportunities we can help you to identify and implement.
Heat pumps
Installing modern high efficiency heat pumps will make a significant difference as heat pumps are at least four times more efficient than gas pumps. This means they significantly reduce energy requirements leading to impressive cost savings.
Refrigerant flow
With more efficient heating and cooling equipment, the next step is to incorporate variable refrigerant flow into the system. This allows precise control over the rate of heating and cooling in different parts of the building, matching it to what’s needed at any given time.
Thermal insulation

Smart technologies
Smart sensors and programmable thermostats can be designed into the system to provide real-time feedback on where heating and cooling is needed based on building occupancy and outside conditions. They can also learn the building’s temperature pattens and programme accordingly. This helps avoid running HVAC systems when they’re not needed, therefore reducing energy consumption and energy bills.
Ventilation strategies
Other ways smart MEP design can support energy efficiency include integrating natural ventilation where possible and fitting better insulation and air seals. Fully co-ordinated and optimised ventilation fabrication drawings at the design stage will ensure an HVAC refit that runs to time and to cost.
Lighting efficiency
An easy win to improve the energy efficiency of an older building is to refit it with LED lights, which are more efficient and have a longer lifespan than traditional bulbs. Even a simple replacement, supported by detailed drawings, can create an opportunity to significantly improve energy efficiency. Instead of just replacing lights, MEP drawings can simulate the new specifications of more modern, energy efficient lighting and help to replan the layout for optimal lighting and energy efficiency.
Smarter lighting
Good MEP design uses lighting simulations to understand the impact of window and skylight placement, to maximise natural light. Using BIM it is possible to simulate and adjust parameters like light distribution in a space, lighting intensity and shadow effects, taking into account both light fittings and incoming natural light. It is possible to test and analyse the placement of different lighting options and their effects on energy efficiency, long before anything happens on site.
For another level of optimisation, including smart sensors in the lighting design allows precise control of lighting according to occupancy and levels of daylight in different areas of the building. This saves energy for our clients, while also improving the indoor environment for their building users. BIM can be used to simulate footfall and occupancy and therefore to identify where sensors are needed.

Energy recovery
Both wastewater and exhaust air that have been heated represent a loss of potentially useful energy from the system.
Heat exchangers can be used strategically to recapture heat from grey water (from sinks, showers and similar) or from water used in heating systems and uses it to heat fresh water from the mains.
Heat recovery ventilators capture heat from exhaust air and, as with water, use it to preheat incoming fresh air. Both options reduce the energy consumption of the building.
MEP Services for energy efficiency
Our services can successfully support you with both operating carbon reduction and embodied carbon reduction. Our cutting-edge MEP design work can make it easy for your team to find opportunities to reduce carbon during the construction phase, as well as to design MEP systems that use less energy (and therefore carbon) during operation.
- MEP: co-ordinated 2D and 3D services offering drawings and BIM for HVAC, pipework, public health and electrical systems.
- BIM: 3D modelling that enables multiple contractors and disciplines to collaborate on clash detection and optimisation for MEP systems to avoid changes on site.
- Point Cloud (3D) Scanning: create accurate models of exposed MEP systems to give all disciplines accurate data on the existing site.
- Ventilation System Drawings: detailed and comprehensive drawings for ventilation systems and ductwork fabrication.
Our services in practice
MultiCAD have been working on a large decarbonisation project in partnership with Nationwide Air Conditioning. It involved a significant equipment upgrade, installing 4-pipe heat pump chillers to replace a set of 5 air cooled chillers.

We used 3D laser scanning to map the existing space and 3D modelling to stage 5. Our services ensured that every opportunity for optimal decarbonisation was identified and gave everyone involved in the project the data needed to work effectively and collaboratively towards the end goal.
Realise more energy savings for your clients
Contact us to talk about how our MEP services can improve energy efficiency for your clients.