An indicative extension timeline
Every extension programme is property-specific. The ranges below are early planning guides, not promised durations. Some stages overlap; others cannot progress until information, selections or approvals are resolved.
| Stage | Indicative range | Typical focus |
|---|---|---|
| Consultation | 1–2 weeks | Goals, property context, available information and the next investigation. |
| Design | 2–6 weeks | Concepts, plans, consultant input and design development. |
| Approvals | 4–12+ weeks | Documentation, CDC or DA assessment and requested information. |
| Construction | 12–24+ weeks | Site works, structure, enclosure, services, finishes and inspections. |
| Completion | 1–2 weeks | Final checks, agreed rectification items and handover. |
What happens before construction starts
Brief and property review
The team first needs to understand the spaces you want, how the current home works, the property constraints and what information is already available. A survey or specialist advice may be needed before a concept can be tested properly.
Design and coordination
Concept plans become more resolved as structure, services, energy requirements, selections and cost implications are considered. Late changes can send completed work back through coordination, so decisions need a clear sequence.
Approval and pre-construction information
The applicable pathway may be exempt development, complying development or a development application, depending on the property and proposal. The NSW Planning Portal approval guide explains the main routes and notes that additional documentation or reports may be requested during assessment.
Planning Around a Target Date?
Start with the property, scope and approval pathway. JYL can help identify the information needed for a more useful programme discussion.
Discuss Your Timeline →How the construction sequence develops
A typical sequence may include site establishment and protection, demolition, excavation or structural preparation, framing, roofing and external enclosure, rough-in services, insulation and linings, cabinetry and finishes, fit-off, inspections and handover. Ground-floor and second-storey projects organise these stages differently.
Some parts are sequential: a finish cannot be installed before the substrate and services are ready. Other activities can overlap when access, trades and inspections allow. A practical programme includes decision dates for owner selections and time for ordered products.
What can change the programme
- Approval assessment, requests for further information or design changes.
- Survey, engineering or other consultant information arriving later than planned.
- Unknown site conditions discovered after opening or excavation.
- Weather affecting excavation, structure, roofing or external finishes.
- Material lead times, unavailable products or late selections.
- Variations to the agreed scope, plans or finishes.
- Trade, inspection, utility or certifier availability.
- Access restrictions and the need to keep parts of the home safe and usable.
The NSW Planning Portal identifies approval processes, weather, material shortages and trade availability as factors that can affect building timeframes. A programme should be updated when the information or agreed scope changes.
Programme planning checklist
- Share any target dates, but keep flexibility until scope and approvals are clearer.
- Gather surveys, plans and property information early.
- Confirm the approval pathway and required consultant documents.
- Resolve long-lead selections before they can delay site work.
- Understand when access, water, power or parts of the home may be disrupted.
- Agree how programme updates and delays will be communicated.
- Document changes and review their time as well as cost impact.
- Plan handover, final inspections and agreed rectification time rather than treating practical completion as instantaneous.
Common questions
Can design and approvals happen at the same time?
Some preparation can overlap, but the application needs sufficiently resolved and coordinated information. Major design changes during assessment can create rework or require additional review.
Can I stay in the home during construction?
It depends on the work area, safe access, services, dust, noise and whether essential rooms remain usable. The living arrangement should be discussed before construction planning is finalised.
Is a second-storey addition always slower?
Not necessarily. Roof removal, structural work and weather protection can add complexity, while ground-floor work may involve excavation, drainage, access or large structural openings. The actual scope determines the programme.
