You should organise BASIX and NatHERS before lodging your Development Application (DA) or Complying Development Certificate (CDC). Councils and certifiers need these documents to verify that your project meets NSW planning requirements.

Engaging Evergreen Energy Consultants early gives you time to adjust design elements (if necessary) without disrupting your timeline or budget.

Typical triggers for BASIX and NatHERS

• New single dwellings and dual occupancies.
• Alterations and additions above the cost threshold.
• Secondary dwellings (granny flats).
• Multi‑unit residential buildings (Class 2) – each dwelling must comply.
• Swimming pools and outdoor spas over 40,000 litres.

Milestones in a typical project

1. Concept design – discuss orientation, glazing strategy and insulation assumptions with us to avoid future rework.
2. Development/CDC stage – we complete the formal BASIX Certificate and NatHERS Assessment for lodgement.
3. Construction documentation – confirm specifications (e.g., final window schedule) align with the certificate.
4. Construction – ensure on‑site choices match the commitments (e.g., insulation R‑values, water tank size).
5. Handover – keep the certificate with project records for future reference.

What if my plans change?

Changes happen. If you alter glazing, insulation, orientation or building fabric, it can affect your BASIX or NatHERS results. Contact Evergreen EC to update your assessment – it’s usually faster and cheaper than discovering the issue at the end of the build.

Timeline: how long should I allow?

Most assessments are completed in around three business days once we receive the necessary information. For complex or multi‑unit projects, allow additional time for coordination. If you have a specific DA deadline in Sydney, Newcastle or the Central Coast, let us know and we’ll prioritise accordingly.

Avoid common timing mistakes

• Leaving BASIX to the last minute.
• Assuming a single certificate can cover multiple dwellings.
• Making on‑site substitutions that don’t match the certificate.

Need help sequencing your approvals?

We can map out when to complete BASIX and NatHERS relative to other documentation so your DA or CDC progresses smoothly.

Get your timing right with Evergreen EC

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Written by Evergreen Energy Consultants — accredited BASIX and NatHERS assessors providing residential energy assessments across NSW.