NABERS UK Explained: Why Office Developers Need to Design for Actual Energy Performance
A new office can achieve an impressive EPC.
It can comply comfortably with Part L.
It can have photovoltaic panels, high-efficiency chillers, heat pumps and intelligent controls.
None of those things answer the most basic question:
How much energy will the building actually use when people move in?
That is the problem NABERS UK is designed to address.
Rather than judging a building primarily on theoretical performance, NABERS focuses attention on operational energy.
For developers, landlords and investors, that distinction is becoming increasingly important.
What is NABERS UK?
NABERS originated in Australia and has been adapted for the UK office market.
In the UK, the scheme is administered by CIBSE.
There are two key offerings for offices:
NABERS UK Design for Performance, aimed at new office developments and major refurbishments
NABERS UK Energy for Offices, which measures the energy performance of existing offices
The concept is straightforward.
Instead of stopping at design compliance, the project makes a commitment to achieve a specific level of operational performance.
That changes the conversation between the developer, design team, contractor and eventual building operator.
NABERS UK versus an EPC
This is one of the most important distinctions.
An EPC is useful.
But an EPC and NABERS are not trying to answer exactly the same question.
An EPC assesses a building using standardised assumptions.
That makes it valuable for benchmarking and regulatory purposes.
NABERS focuses much more strongly on measured energy performance in use.
Consider two identical office buildings.
They have the same façade.
The same heat pumps.
The same ventilation system.
The same EPC.
Building A is carefully commissioned, monitored and managed.
Building B runs ventilation overnight, has poorly configured controls and regularly heats and cools the same spaces at the same time.
The EPC may not reveal much difference.
The energy meters will.
That is the territory NABERS is interested in.
NABERS versus BREEAM
BREEAM is broader.
It assesses multiple sustainability issues across categories such as energy, management, water, materials, transport, health and wellbeing.
NABERS is much narrower.
And that is precisely the point.
It looks closely at operational energy performance.
A project therefore does not necessarily choose between BREEAM and NABERS.
They can serve different purposes.
In fact, leading UK office developments increasingly pursue multiple performance frameworks when those frameworks support the client's objectives.
Max Fordham's 11 Belgrave Road, for example, achieved a 5.5-star NABERS UK Design Reviewed Target Rating alongside BREEAM Outstanding and WELL Platinum.
What is Design for Performance?
NABERS UK's Design for Performance, or DfP, is intended for new office developments and major refurbishments.
The developer or owner commits to designing, constructing and commissioning the building to achieve a specific NABERS UK Energy rating.
That commitment influences the project before occupation.
Projects registered under the framework must undertake an Independent Design Review assessing whether the design is likely to achieve the chosen operational-energy target.
This is important.
Energy performance becomes something the project must actively protect during design and delivery.
Not something checked once at the end.
Why operational energy predictions go wrong
Energy models do not fail because engineers cannot calculate.
They often fail because buildings are complicated.
A model requires assumptions about:
occupancy
working hours
equipment loads
heating setpoints
cooling setpoints
ventilation rates
control behaviour
tenant equipment
weekend use
cleaning schedules
server rooms
catering
lifts
Change the assumptions and the result changes.
This is why a compliance model should not automatically be treated as a forecast of real energy consumption.
A realistic operational-energy model asks:
How is this particular building genuinely expected to operate?
The landlord and tenant problem
Commercial offices create another challenge.
Who actually controls the energy?
The landlord may control central heating, cooling, ventilation and common areas.
Tenants control lighting, equipment, plug loads and sometimes parts of the HVAC system.
A building can therefore have excellent central systems and still consume far more energy than expected.
Or a highly efficient tenant can occupy a relatively inefficient base building.
Hoare Lea has highlighted this distinction when discussing how NABERS separates landlord and tenant energy considerations in the office sector.
For developers, the lesson is that responsibilities for energy performance need to be clear.
Metering becomes part of the design
You cannot improve what you cannot diagnose.
A good operational-energy strategy therefore needs a useful metering structure.
That may include separate monitoring for:
heating
cooling
ventilation
lighting
landlord systems
tenant areas
domestic hot water
lifts
data centres
renewable generation
Simply installing dozens of meters is not enough.
The design team needs to ask:
What question will this meter help the building operator answer?
If nobody knows, the meter is likely to become another unused data stream.
MEP design matters enormously
NABERS is not simply an energy-modelling exercise.
The mechanical and electrical systems need to be capable of delivering the target.
Common risks include:
Oversized equipment
Plant operating far below its design point may perform inefficiently.
Excessive ventilation
Providing more air than required uses fan energy and can increase heating or cooling demand.
Poor zoning
Large zones make it difficult to respond to actual occupancy.
High pressure drops
Ductwork and pipework design directly affects fan and pump energy.
Simultaneous heating and cooling
A surprisingly common controls problem.
Poor part-load performance
A system may be efficient at peak load but spend most of the year operating elsewhere.
Weak controls logic
The best equipment cannot compensate for a control system that runs it unnecessarily.
NABERS pushes these conversations towards actual performance rather than equipment labels.
Controls deserve more attention than they usually receive
Imagine investing in high-performance heat pumps and ventilation systems.
Then the building controls start everything at 5am every morning because nobody updated the schedule after commissioning.
The plant might be efficient.
The building is not.
Controls determine:
when equipment operates
how it responds to occupancy
how temperatures are maintained
whether heating and cooling overlap
how ventilation rates change
how faults are detected
This is one reason NABERS-style performance thinking needs MEP engineers, building-performance specialists and facilities teams working together.
Commissioning is not the finish line
Traditional project delivery can create a dangerous moment.
Practical completion arrives.
The contractor leaves.
The design team reduces its involvement.
The facilities team inherits a very complicated building.
Then real operation begins.
A high-performing building needs more than one commissioning exercise before handover.
Systems often need fine tuning once realistic occupancy patterns are visible.
Summer and winter performance may reveal different problems.
This is where Soft Landings and post-occupancy support become valuable.
Why developers should care commercially
Energy performance is not just an environmental issue.
An inefficient office can create:
higher service charges
uncomfortable occupants
tenant complaints
ESG problems
unnecessary carbon emissions
difficulty demonstrating net-zero progress
reputational risk
A genuinely high-performing building can provide a much stronger story.
Not:
Our model says this building should be efficient.
But:
We designed for a defined operational target and can demonstrate how performance is being measured.
That difference becomes more valuable as investors and occupiers become more sophisticated about building performance.
NABERS and the wider move towards measured outcomes
NABERS is part of a larger change in the UK market.
The UK Net Zero Carbon Buildings Standard Version 1 was published in March 2026 and applies to new buildings, existing buildings and retrofits. Its approach also places significant emphasis on real building performance and verification.
The direction is therefore increasingly clear.
Sustainability claims are moving from:
What did the design intend?
towards:
What does the building actually do?
NABERS fits naturally into that shift.
When should NABERS be considered?
Not during commissioning.
Not after detailed MEP design.
And definitely not once the building has been completed.
The target should influence the brief.
During RIBA Stages 1 and 2, the team should consider:
operational-energy targets
façade performance
HVAC strategy
plant efficiency
zoning
controls philosophy
metering
tenant assumptions
hours of use
renewable generation
commissioning
aftercare
By Stage 4, many of the biggest energy decisions have already been made.
A better way to think about office energy
There are essentially three levels.
Level 1: Compliance
Can the building legally be constructed and occupied?
Level 2: Prediction
How much energy is the building realistically expected to consume?
Level 3: Verification
What does it actually consume?
A mature building-performance strategy considers all three.
Problems arise when teams assume Level 1 automatically guarantees Levels 2 and 3.
It does not.
How Climery can help
Climery combines building-performance analysis with MEP engineering and environmental advisory, allowing energy targets to influence the actual building design.
Support can include:
Operational-energy target setting
NABERS-aligned design advice
Energy modelling
MEP design and optimisation
HVAC options analysis
Metering strategies
BMS and controls strategy
Commissioning planning
Post-occupancy evaluation
Building tuning and optimisation
The objective is not simply to design an efficient building.
It is to design a building capable of remaining efficient once people start using it.
Developing or refurbishing a UK office and considering NABERS or operational-energy targets? Talk to the Climery team during the early design stages.
FAQs
What does NABERS UK measure?
NABERS UK focuses on energy performance in office buildings. The UK scheme includes Design for Performance for new developments and major refurbishments and Energy for Offices for existing assets.
Who administers NABERS UK?
CIBSE administers the NABERS UK scheme.
What is NABERS UK Design for Performance?
It is a process in which a developer or owner commits to designing, building and commissioning a new office or major refurbishment to achieve a defined NABERS UK Energy target.
Is NABERS the same as an EPC?
No. EPCs are based on standardised calculations, while NABERS places much greater emphasis on real operational energy performance.
Is NABERS only relevant after a building is occupied?
No. Design for Performance is specifically intended to influence the design and construction process before occupation.
