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Performance Solutions vs Deemed-to-Satisfy: When to Use Each Under the NCC
A single DTS departure can force a difficult choice: change the design or demonstrate compliance another way. If a building design does not meet a Deemed-to-Satisfy (DTS) provision in the National Construction Code (NCC), the design can still achieve compliance through alternative pathways and does not need to be abandoned.
The NCC allows its Performance Requirements to be satisfied through a Performance Solution, a Deemed-to-Satisfy Solution, or a combination of both, as set out in NCC 2022 A2G1.
Architects, developers, and project teams should focus not only on whether the design meets DTS, but on choosing the most suitable NCC compliance pathway and understanding how to demonstrate compliance.
Understanding the difference between a Performance Solution and a Deemed-to-Satisfy Solution early allows the project team to identify compliance issues before advancing documentation, approvals, or construction.
In This Article
- How NCC Compliance Pathways Work
- DTS vs Performance Solution
- When to Use Deemed-to-Satisfy
- When to Use a Performance Solution
- The Performance Solution Process
- Performance-Based Design Brief
- How a Performance Solution Is Assessed
- Combining Both Pathways
- When to Decide the Pathway
- Choosing Your Pathway
- Practical Takeaways
- FAQs
How Do NCC Compliance Pathways Work?
The NCC is performance-based. Its Performance Requirements set the minimum standards that a building, plumbing, or drainage solution must meet.
Those requirements can be satisfied through:
| Compliance Pathway | How It Works | |
|---|---|---|
| Deemed-to-Satisfy Solution | Follows the applicable DTS provisions within the NCC. | |
| Performance Solution | Demonstrates compliance with the relevant Performance Requirements using appropriate Assessment Methods. | |
| Combination | Uses both DTS and Performance Solutions. |
| Deemed-to-Satisfy | Performance Solution | |
|---|---|---|
| Basis | Prescribed NCC provisions | Demonstrated performance |
| Approach | Follow applicable DTS provisions | Demonstrate satisfaction of relevant Performance Requirements |
| Design flexibility | Works within prescribed provisions | Allows project-specific approaches |
| Assessment | Against DTS requirements | Uses recognised Assessment Methods |
| PBDB | Not generally required | Required as part of the Performance Solution process |
| Typical use | Design can meet DTS | Alternative approach needs to be assessed |
Neither pathway is always better than the other. The right choice depends on the design, the requirements, and any project constraints.
When Should You Use Deemed-to-Satisfy?
The DTS pathway usually works well when the design meets the required provisions without causing major conflicts with the project’s design or how it needs to operate.
For many parts of a building, this gives a clear way to show NCC compliance.
However, projects with complex architecture, existing buildings, unusual layouts, or other challenges may find DTS difficult to apply. In these situations, the team should decide whether to modify the design or use a Performance Solution.
When Should a Performance Solution Be Considered?
A Performance Solution is not needed just because a project is complex. It is used when the team needs a different way to show that the Performance Requirements are met. Common situations include:
1. The Design Does Not Meet a DTS Provision
Not meeting DTS does not always mean the design must be abandoned.
The team can identify the relevant Performance Requirements and decide if the design should be changed to meet DTS or if a Performance Solution is a better option.
2. DTS Would Significantly Affect the Proposed Design
Strictly following a DTS provision might conflict with an architectural, operational, or project-specific need.
A Performance Solution allows you to use a different technical approach, provided it meets the required performance level. This approach maintains compliance standards, and the solution must still demonstrate that it satisfies the relevant Performance Requirements.
3. The Project Has Unusual or Existing Conditions
Existing buildings and complex projects often do not fit within the set requirements.
When site conditions, existing construction, or unusual layouts prevent following DTS provisions, the team should consider a project-specific alternative compliance pathway under the NCC.
4. Only One Part of the Design Departs From DTS
A project does not need to use only DTS or only Performance Solutions for the whole building.
The NCC allows both pathways to be used together. Most parts of a building can follow DTS, while a specific issue like fire safety, access, or another compliance matter can be handled with a Performance Solution.
This is especially helpful when only one design issue needs a different approach, but the rest of the project can still use DTS provisions.
What Is the NCC Performance Solution Approach?
A Performance Solution involves more than just explaining why a DTS provision cannot be followed.
The NCC establishes a systematic process for developing and evaluating the solution:
- Prepare a Performance-Based Design Brief
- Carry out the analysis
- Evaluate the results against the agreed acceptance criteria
- Prepare the final report
This process sets out what needs to be shown, how it will be checked, and what evidence will support the compliance decision.
This is why it is important to spot possible DTS departures early. Depending on the issue, a Performance Solution might need input from BCA consultants, fire engineers, access consultants, or other specialists.
Unsure Which NCC Pathway Suits Your Project?
Getting compliance advice early can help find possible DTS departures and suitable Performance Solution pathways before they cause extra design, documentation, or approval problems.
Discuss Your Project →What Is a Performance-Based Design Brief?
The Performance-Based Design Brief (PBDB) sets the foundation for creating and assessing a Performance Solution.
Instead of doing the analysis first and justifying the design later, the performance design brief sets out things like:
- The scope of the Performance Solution
- Relevant Performance Requirements & DTS provisions
- Proposed Assessment Methods
- Acceptance criteria
- Required analysis or testing
- Relevant stakeholders and specialist input
The amount of detail depends on how complex the proposed solution is. The goal is to agree on a framework for showing compliance before starting detailed analysis.
How Is a Performance Solution Assessed?
The NCC recognises several Assessment Methods for showing compliance. These can be used alone or together, depending on what is needed. They include:
- Evidence of Suitability
- Verification Methods
- Expert Judgement
- Comparison with the Deemed-to-Satisfy provisions
The right Assessment Method depends on the Performance Solution and the evidence needed to show that the relevant Performance Requirements are met.
This is a key difference between DTS and Performance Solutions. Just preferring a different design is not enough reason to leave a DTS provision. The alternative must be backed by a proper assessment.
Can Performance Solutions and DTS Be Combined?
Yes, the NCC clearly allows you to combine Performance Solutions and Deemed-to-Satisfy Solutions.
For example, most parts of a development might follow DTS provisions, while one design element needs a BCA Performance Solution.
When both pathways are used, the relevant Performance Requirements must be identified, and the combined solution must meet all the necessary requirements.
The choice between Performance Solution and Deemed-to-Satisfy is often made for a specific compliance issue, not for the whole building.
When Should the Compliance Pathway Be Decided?
It is best to identify possible DTS departures while the design can still be changed, because the broader compliance risk is significant.
Building Commission NSW’s 2025 research found serious defects in 53% of the Class 2 strata buildings surveyed, with fire safety systems among the most common defect categories. While this data does not specifically measure DTS departures or Performance Solutions, it highlights the importance of resolving building compliance requirements before they become part of the completed building.
If an issue is found after documentation is well underway, the team might have to redesign the affected part or start developing a Performance Solution when coordination and documentation are already advanced.
An early BCA review can help figure out:
- Where the design complies with DTS provisions
- Where potential departures exist
- Whether redesign or a Performance Solution should be investigated
- What specialist input may be required
- How the compliance pathway may affect design development
Not every DTS departure needs to lead to a Performance Solution. Sometimes, it is more practical to change the design to meet DTS compliance.
The key is to make that decision with a clear understanding of the compliance requirements and what they mean for the project.
Which NCC Compliance Pathway Should You Use?
A good place to start is:
| Project Situation | Pathway to Consider |
|---|---|
| Design meets applicable DTS provisions | Deemed-to-Satisfy |
| Design does not meet a DTS provision | Consider redesign or a Performance Solution |
| Alternative technical approach is proposed | Assess a Performance Solution |
| Only specific elements depart from DTS | Combine DTS and Performance Solutions |
| Complex or unusual conditions exist | Review the compliance pathway early |
For architects and developers, it is best to answer this question before a compliance issue becomes part of the design.
AI Consultancy helps project teams review designs against NCC requirements, find possible compliance risks, and create practical Performance Solution pathways when DTS provisions do not fit the design. This matches its wider Building Regulation (BCA) services, including BCA Design Reviews & Reports, compliance reporting, and performance-based compliance.
Practical Takeaways
A Performance Solution is not a shortcut around the NCC. It is a recognised compliance pathway that demonstrates the relevant Performance Requirements are met using appropriate Assessment Methods, supported by a Performance-Based Design Brief and a documented assessment.
Deemed-to-Satisfy remains the most direct pathway where the design fits the prescribed provisions. The decision between the two is usually made for a specific compliance issue rather than for the whole building, and both pathways can be combined on the same project.
The earlier a potential DTS departure is identified, the more options the project team has. An independent BCA review during concept or schematic design helps determine whether a redesign or a Performance Solution is the better route, and what specialist input will be required, before documentation and coordination are locked in.
Resolve DTS Departures Before They Affect Your Design
Get early BCA advice to assess the departure, determine the appropriate compliance pathway, and coordinate any Performance Solution requirements before documentation progresses.
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FAQs
Frequently Asked Questions
Is a Performance Solution the same as an Alternative Solution?
“Alternative Solution” is the former BCA/NCC term for what is now called a Performance Solution under the National Construction Code. In Australia, always use “Performance Solution” to ensure compliance with current NCC requirements and industry standards.
Does departing from DTS automatically require a Performance Solution?
Departing from DTS doesn’t always mean you need a Performance Solution under the NCC. In Australia, you can either modify the design to meet DTS provisions or use a Performance Solution to demonstrate compliance with Performance Requirements.
Can DTS and Performance Solutions be used on the same project?
Yes, in Australia, you can use both Deemed-to-Satisfy (DTS) and Performance Solutions together on one project. The National Construction Code (NCC) supports combining these pathways to meet compliance requirements for various building designs.
