The hidden cost of unauthorised Building Works: What homeowners need to know
In the past, unauthorised building works were usually a problem that surfaced when someone decided to sell their home. Issues like a pergola added without approval, a garage converted into a room, or a deck that somehow slipped under the radar. These issues would emerge during conveyancing, often causing stress, delays, and unexpected costs right when owners thought they were ready to move on.
Today, however, the challenge of unauthorised works is showing up much earlier, and often hitting unsuspecting homeowners in the final stages of construction.
When “small changes” become big problems
It’s becoming increasingly common for homeowners to discover, often too late, that the approved plans have not been followed in full or the additional work they requested during construction might be a problem. It might be a retaining wall added “for convenience,” a window slightly repositioned, or an internal layout adjusted on site.
While these changes can seem minor, even well-intentioned, they can have major consequences.
If a certifier identifies any unauthorised works, meaning the built outcome doesn’t match the approved documentation, they are unable to issue the Occupation Certificate (OC).
Without an OC, you cannot legally occupy the building. This can delay moving in, hold up settlements, and trigger insurance or lending issues.
The ripple effect: unexpected costs and delays
When this happens, homeowners are often surprised to learn that they need additional documentation to rectify the issue. Typically, this means applying for a Building Information Certificate (BIC) from Council, which requires updated drawings and reports from various consultants that accurately reflect what has been built.
At this stage, many people turn to us for help. We’re asked to prepare as-built drawings, liaise with consultants, and coordinate with Council or private certifiers to ensure compliance. It’s a process we’re experienced in managing, but one that can involve additional time, fees, and frustration for homeowners who thought everything was already complete.
Why this is happening more often
There are a few reasons this issue is becoming more common:
- Stricter certification requirements – Councils and private certifiers have become more stringent in final inspections.
- Design changes on site – Builders or subcontractors making quick decisions without formal documentation.
- Lack of communication – Homeowners unaware that a change, even a minor one, still needs approval.
- Pressure to complete – Tight schedules sometimes lead to shortcuts in documentation or approvals.
How to protect yourself from unauthorised works
While not every variation can be predicted, there are important steps to help you avoid costly surprises:
- Ensure your builder is working from the approved stamped plans.
Keep a copy on site and refer to it regularly. - Don’t agree to on-site changes without written approval.
Even small adjustments should be confirmed with your certifier and architect or designer. - Stay in touch with your certifier throughout construction.
Regular communication can catch potential issues early. - Engage your architect beyond the approval stage.
Ongoing involvement helps monitor compliance and avoid retrospective certificates later.
Our role in resolving unauthorised works
At Ruth Newman Architect, we’re seeing more clients seeking help after the fact, often when a project is close to completion, but the certifier cannot issue the Occupation Certificate. Preparing drawings and the documentation for a Building Information Certificate is one way we can help bring the project back into compliance, but it’s always better to prevent the problem before it starts.
The best outcomes happen when everyone – homeowner, builder, certifier, and architect – works together from start to finish, keeping documentation consistent with what’s built on site.
Final thoughts
Building projects are complex, and small changes can happen. However, in today’s regulatory environment, unauthorised works can have far-reaching implications, from delayed occupancy to unexpected costs.
A little vigilance during construction can save a great deal of stress later.
If you’ve encountered this situation or need guidance on rectifying unauthorised works, we can help assess your options and prepare the necessary documentation to bring your project back on track. Contact us now!
by Ruth Newman
If your builder deviates from the approved plans, even slightly, it can result in unauthorised building works. This means the project no longer complies with your Development Application (DA) or Complying Development Certificate (CDC). As a result, the certifier may refuse to issue an Occupation Certificate (OC) until the issue is resolved. In most cases, homeowners will need to apply for a Building Information Certificate (BIC) and submit updated as-built drawings to Council to bring the project back into compliance.
What is a Building Information Certificate (BIC) and when do I need one?
A Building Information Certificate (BIC) is a formal approval issued by Council under the Environmental Planning and Assessment Act 1979 (NSW). It confirms that existing building work, whether completed recently or years ago, is acceptable and unlikely to be subject to enforcement action.
You’ll typically need a BIC if:
Works were completed without approval; or
The final construction differs from the approved plans; or
A certifier cannot issue the Occupation Certificate due to unapproved changes
At this stage, an architect can help prepare the necessary drawings and liaise with the Council to support your application.
How can I avoid unauthorised works during construction?
Prevention starts with clear communication and documentation. Always ensure your builder is working from the approved stamped plans and never authorise on-site changes without consulting your architect or certifier. Regular site inspections and ongoing involvement from your architect can help identify compliance issues early, long before they become costly delays. Staying proactive throughout construction is the best way to avoid the stress and expense of applying for a Building Information Certificate later.