Overview
Design for Performance helps you predict operational energy performance before occupation and then verify the outcome in use. It provides a clear target, independent scrutiny and a practical plan to protect performance through design, delivery and early operation.
What we need from you to start
A short briefing at the outset improves the quality of the modelling, reduces programme risk and helps you protect the target rating through delivery.
- Project stage and intended programme to Stage 4 and handover.
- Gross internal area, net lettable area and expected hours of operation.
- Servicing intent (air system, water system, mixed mode and tenant fit-out assumptions).
- Controls intent (setpoints, schedules, ventilation control approach and zoning strategy).
- Metering approach and who is responsible for landlord and tenant energy boundaries.
- Target rating ambition and any parallel targets (BREEAM, WELL and net zero commitments).
Evidence from delivery
On 30 Semple Street in Edinburgh, KJ Tait delivered Scotland’s first Design for Performance accredited scheme, with a NABERS target rating of 5 stars confirmed following Independent Design Review. Read the case study.
- Modelling showed a 24% reduction in energy demand from enabling mixed mode operation with openable windows and controls interlocks.
- Further savings were identified through demand control ventilation (15%) and an AHU economy cycle strategy (11%).
- The metering strategy was developed to conform to NABERS UK rules and separate landlord energy from tenant lighting and small power.
- The Rating Achievement Plan included Soft Landings, monthly in-use energy reporting and an in-use assessment after 12 months of at least 75% occupation.
Performance, Comfort and Sustainability
Set a measurable target, test design choices against it and carry the assumptions into commissioning and early aftercare.
Reduce the risk of unstable temperatures and ventilation issues by aligning controls strategy, plant selection and operational intent.
Provide credible evidence for operational energy performance, supporting net zero pathways and responsible decision making.
DfP scope and metering checklist
DfP relies on clear energy boundaries and metering arrangements so the verified rating reflects the intended scope. Agreeing these early reduces risk at handover.
- Confirm what is in scope for the target rating and how it will be measured.
- Separate landlord energy from tenant lighting and small power in the metering design.
- Agree sub metering locations, labelling and evidence requirements for verification and tuning.
- Capture responsibilities in the Rating Achievement Plan and contractor requirements.
Why use Design for Performance?
DfP helps you shift from “designed to comply” to “designed to operate”. The focus is on realistic operational assumptions, evidence and a delivery plan that protects performance.
Where this helps most: value engineering, controls strategy decisions, metering scope and handover planning. These are common points where performance can drift if the target is not actively protected.
Who DfP is for
Developers and asset managers
- You want a credible operational energy target that the market recognises.
- You want independent review to reduce delivery risk.
- You want clear requirements to brief designers, contractors and operators.
Occupiers and investors
- You want evidence-led performance, not marketing claims.
- You want a building that is efficient, comfortable and straightforward to operate.
- You want clarity on what is measured and why.
How KJ Tait delivers DfP
We support you from early design decisions through Stage 4 submission, commissioning and early operation. We use detailed HVAC modelling to test system performance, highlight risks early and help you protect the target rating through delivery.
What you get
- Operational energy model that reflects how the building will be used and controlled.
- Simulation Report aligned to DfP requirements and ready for Independent Design Review.
- Rating Achievement Plan that turns modelling assumptions into practical delivery actions.
- Metering and monitoring inputs so energy data can be verified and used to manage performance.
- Handover and early aftercare support to reduce performance drift and protect outcomes.
DfP process (clear steps)
- Set the target early. Agree the rating ambition, scope and responsibilities so design decisions have a stable reference.
- Define how the building will operate. Capture assumptions for occupancy, hours, internal loads and controls intent.
- Model the building as it will operate. Test fabric, plant selection, distribution and controls strategy.
- Stress test performance risks. Identify the choices most likely to shift energy use in operation and set mitigations.
- Prepare Stage 4 submissions. Produce the Simulation Report and Rating Achievement Plan for Independent Design Review.
- Lock in delivery requirements. Translate the plan into specifications, commissioning evidence and handover information.
- Support early operation. Review controls and metered data and address drift so outcomes stay aligned to the target.
In use, the rating is verified using real energy data once occupancy is established and the building is operating normally.
Deliverables and decision points
Design (Stages 2–4)
- Operational assumptions pack (hours, loads and controls intent).
- Iterative model outputs to inform design choices and value decisions.
- Simulation Report for Independent Design Review.
- Rating Achievement Plan with clear actions and responsibilities.
Delivery and early operation
- DfP aligned Employer’s Requirements inputs (where applicable).
- Commissioning and witnessing focus areas tied to performance risks.
- Metering and trending requirements for verification and tuning.
- Aftercare plan including reviews of controls and energy data.
Common reasons offices miss the target
DfP reduces risk, but it does not remove it. Most underperformance is avoidable if it is identified early and managed through delivery.
- Operational assumptions drift (hours, occupancy and small power not aligned to the agreed basis).
- Controls do not match intent (schedules, setpoints and demand control not configured as planned).
- Metering is not verification-ready (scope gaps or unclear separation of landlord and tenant energy).
- Value engineering is not re-tested (changes made without checking the impact on the target).
- Handover is compressed (insufficient time for tuning, seasonal checks and operator training).
FAQs
Is Design for Performance the same as an EPC?
No. Design for Performance is intended to predict and verify operational energy outcomes, while EPCs are an asset rating based on a standardised methodology. They answer different questions.
When should you start Design for Performance on an office project?
Start early enough that the target rating can influence façade, servicing strategy, controls approach and metering. If you start late, you typically lose the ability to reduce risk without cost and programme impact.
What do you submit for Independent Design Review?
Typically this includes the Simulation Report and the Rating Achievement Plan, together with supporting design information required to demonstrate assumptions, system intent and performance risks.
What is the Rating Achievement Plan used for?
It turns modelling assumptions into delivery actions. It sets out what must happen in specification, commissioning, handover and early operation to protect the target rating.
What happens after practical completion?
Your focus shifts to stable operation: validating controls, reviewing metered data, supporting the operational team and addressing performance drift. This early period is often where the target rating is protected or lost.
What does Design for Performance cover and what is excluded?
DfP applies to the energy uses within the defined NABERS UK scope for the project. Agreeing the scope and metering approach early is essential so verification is clear and reliable.
How and when is the target rating verified in use?
The rating is verified using real energy data once the building is occupied and operating normally. Early operation is the key period for tuning controls and preventing performance drift.
What is the Independent Design Review and why is it important?
Independent Design Review checks the design documentation and modelling approach against the DfP requirements. It strengthens credibility by identifying risks and confirming that the target rating is supported by evidence.
Useful links
Next steps
If you are considering NABERS UK Design for Performance for an office new build or major refurbishment, we can help you set a credible target, define the scope, plan the evidence and manage risk through delivery.
If you prefer, share your project stage, location, approximate size and intended servicing approach. We will respond with a focused scope, programme view and information requirements.
