Top 5 Mistakes That Lead to Section J Non-Compliance (And How to Avoid Them)

Most builders and designers don’t lose time or money just on construction. They can also lose it on Section J non-compliance. 

You submit the plans, expect straightforward approval, and suddenly the project stalls. It’s all because of things like utilising the wrong calculators, missing documentation, or choosing materials that don’t meet NCC performance requirements. 

These errors increase project costs and affect the energy efficiency of the final building. Just so you don’t make the same mistakes, we’ll cover what causes Section J non-compliance issues and how you can avoid them. 

Five Mistakes That Lead to Section J Non-Compliance (With Solutions)

One thing most builders and designers don’t realise is that Section J isn’t difficult because the rules are complicated. It becomes difficult because a single oversight early in the design stage can create a chain of problems as time passes. 

Let’s break down the most frequent mistakes and how you can avoid them. 

Mistake 1: Nominating the Wrong Building Class

One of the most common compliance errors is choosing the wrong building class. If the class is wrong, the report will reference incorrect glazing, insulation, and sealing requirements. This means your entire calculation becomes invalid. 

Remember, Section J requirements differ for offices, apartments, childcare centres, retail shops, aged care, etc. 

Building surveyors often reject reports simply because the class does not match the building’s intended use. Something as small as a “mixed-use” building can trigger different compliance paths.

How to Avoid It

• Check the building class directly from NCC Volume 1.
• Confirm with the project’s building surveyor before the report starts.
• If usage overlaps (e.g., commercial + residential), treat it as multiple classes.

Mistake 2: Using the Wrong Facade or Glazing Calculator

Section J glazing requirements are climate-zone specific. That’s why using a generic calculator or an outdated tool produces incorrect U-values or SHGC values. 

When that happens, even compliant glazing can appear “non-compliant” on paper, which triggers unnecessary upgrades and added costs. This problem usually starts when teams estimate the window area instead of using the exact window schedule. 

In fact, studies show that glazing accounts for up to 40% of unwanted heat loss or gain in commercial buildings, making facade accuracy important. 

How to Avoid It 

• Always use the official NCC façade calculator.
• Enter exact numbers from the architectural drawings.
• Confirm the climate zone before starting (it affects compliance).

Mistake 3: Incorrect Lighting Calculations

Instead of supplying real wattage values from lighting schedules, teams sometimes estimate or use placeholders. 

But the problem is that Section J has strict lighting density limits. If the wattage is even slightly higher, the report fails. In this case, automation matters too, as lighting controls (sensors, timers) reduce energy load and are required in many zones. 

Even though an efficient lighting system can reduce energy consumption, if you use incorrect lighting numbers, those savings are lost. 

How to Avoid It

• Use the NCC lighting calculator, not manual estimates.
• Enter wattage directly from electrical plans.
• Include lighting controls, as they reduce consumption and make compliance easier.

Mistake 4: Not Requesting Additional Information When Details Are Missing

Another major cause of Section J non-compliance is the omission of key details from the architectural plans. 

When information such as glazing type or roof build-up is not clearly shown, the assessor cannot assume anything and must take a conservative approach. 

This often forces stricter specifications, higher insulation costs, or costly glazing upgrades. As a result, the builders end up spending more, simply because they didn’t ask the architect for missing details early on. 

How to Avoid It

• Ask the architect for any missing details before the assessment starts.
• Ensure your plans include window schedules, wall build-ups, and insulation specs.
• If something is still undecided, tell your assessor rather than letting them assume.

Mistake 5: Only Choosing Section J (When J1V3 Would Give Better Results)

Section J is strict or rule-based, but J1V3 allows flexibility. It uses energy modelling to prove compliance and is ideal for projects with larger glazing areas or modern architectural features. 

Teams often choose the standard Section J path, even when the building clearly needs a flexible compliance approach. 

If they go with J1V3 instead, it can reduce costs by simulating different material options rather than imposing rigid glazing or insulation requirements. 

How to Avoid It

• Use J1V3 when architectural design doesn’t fit the Deemed-to-Satisfy rules.
• Ask the assessor early to compare Section J vs. J1V3 options.
• In complex designs, J1V3 typically avoids unnecessary glazing upgrades.

Make Section J Compliance Easy with PassivEnergy

Section J compliance can feel overwhelming. Between building classes, glazing values, façade calculators, and documentation requirements, a small mistake can send your plans back for revisions. 

The smart move here is not to try to navigate it alone and let PassivEnergy handle the stress. 

Section J reporting is what we do every day. We know precisely what councils look for, what needs to be documented, and how to get your report approved the first time. All we need from you are the drawings, and we handle the rest. 

Get a free quote and let PassivEnergy handle your compliance!