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Engineer for a Granny Flat – Plus a List of Recommended Ones

When you first start building your granny flat, there are times when you will need the help of a professional. So, do you need an engineer for a granny flat?


Yes – you will need an approved, stamped report by a qualified engineer. This report confirms an engineer has come to your site, performed soil tests, and confirmed what need to be done for the foundation of your granny flat.


Today I will talk about the type of engineer you will need.


DON'T PAY A FORTUNE FOR YOUR GRANNY FLAT. Find out how to deal with council and build a granny flat for the lowest cost possible. Learn More.

I will discuss whether you can be approved without an engineers report and will provide a list of engineers throughout Australia for your project.


What Type of Engineer do You Need?


You will require the assistance of a Structural Engineer.


A Structural Engineer responsibilities include:


  • Analysing the configurations of the basic components of the structure, to ensure it can actually be built.
  • Making sure that the structural design of the granny flat is safe, strong, serviceable, compliant, and durable.
  • Ensuring that the building can endure the stresses and pressures that it will be imposed to from human use and the environmental conditions.
  • Inspecting your property, assessing its’ conditions and foundations.


To verify this, they do calculations, and document it with drawings.


My personal engineering plans showed me exactly how the piers would be built


A good Structural Engineer’s drawings generally include:


  • Plans.
  • Elevations.
  • Detailed designs.
  • Schedules and tables of their calculations.
  • The building materials required.
  • Proposed construction methods that best suit both your project and budget.


Can Your Granny Flat be Approved Without an Engineers Report?


Simply put – no.


The need for Stamped Engineering Plans are in the total list of certificates needed, which are important to make your granny flat compliant.


To elaborate, an Engineers Report:


  • Ensures your new granny flat will be structurally safe and sound.
  • Contains strict guidelines on what structural building materials must be used, due to the condition of your land. This ensures you are meeting the standards of the Building Code of Australia (BCA). For example, my engineers report advised what strength the concrete used in my slab had to be.
  • Will explain every shape, size, and form of every part of the dwelling, so they are drawings that will be accepted by your Council.


What Does an Engineer Do When They Are on Site?


You will need the engineer to come to your property to create the report for you.


When they are on site, they will:


  • Review your requirements – They should start by understanding what your goal is, what the result is that you want to achieve.
  • Check your land and plans – The affect that putting a granny flat on your land will have is huge, and easily underestimated. So, the engineer should take time to assess every aspect your site and its’ condition.
  • They may review your properties classification in comparison to your Section 10.7 Certificate.
  • They will check over any planned design elements for your secondary dwelling, seeing if it suits the condition of your land.
  • They will also measure your soil and confirm the foundation of your granny flat.
  • For example, when the engineer came to my site, they measured the soil to see if our foundation was sitting on rock.

Structural Designs – As part of their role as an engineer, they should now start to give you advice. This will include the best structural designs and materials specifically for your site and build.

For example: they will advise you if cladding is a suitable facade for your granny flat, or you need a stronger material. They will also advise you on the materials you should use for your flooring and roofing.


That’s it – your reports are now almost ready to be issued. First, they should check their work to ensure its’ accuracy.


Then, they will provide you with a copy of designs, reports and certifications.


Does Your Architect or Drafter Need the Engineer Report?


Yes – a good engineer should know how to liaise with other professionals in the industry, such as architects or drafters.


It is important to note that Granny Flat Designers will actually need these engineering plans from you.


You should be able to give your architect or drafter the reports from your surveyor and engineer, and then they can:


  • Begin creating plans, ready to start constructing your granny flat.


What Makes a Good Engineer?


Below is a list of qualities that you should look for in an engineer…Especially if You Have a Challenging Block


Particularly if you have tricky block to work with, such as one on sloping land, you will need an expert in their field.


Here is advice on how to find the right engineer for you:


  • Are They Professionally Registered with the Institute of Structural Engineers –  It is important to establish your engineer is registered and has undertaken Continuous Professional Development (CDP).

Search the Members Directory by name, location or membership number.

  • Do They Work Well in a Team – Often, an engineer will be part of a team, so must be able to work well therein. Qualities to look for that show signs of great teamwork are courtesy and tact when communicating. These traits will build trust within the team. If they can communicate well with you, keeping you informed, presenting facts openly and honestly, they are probably a good team member.
  • Do They Have Good Communication Skills – For an engineer, communication is more than speaking, reading, writing, or listening. It means being able to not only understand technical complexities, but also able to:
  • Concisely, effectively translate this technical language into layman’s terms without talking down to others. Engineers communicate with people at many different levels, from unskilled workers to managers. The ability to communicate in a respectful, concise manner is vital as it ensures your main message will be passed on clearly. So, they should be able to work with you and communicate well with you, helping you understand all the options available to you.
  • Are They Creative – Great engineers are born with an ability to ‘think outside of the box’. Their entire industry relies on the ability to creatively solve problems. Engineers that are able to bring creative solutions and new ideas to the job are improving the existing system. Listen to see if they can come up with new ways to improve existing problems. Simply, pay attention to how effective the solutions they suggest are, and how well received they are.
  • Are They Natural Problem Solvers – As with creativity, an engineer must also be great at problem solving. Any job, no matter its’ size, will have its’ problems. An engineer must be able to address these as they appear. This means studying the problem, understanding the impact it is having on the project, and analysing it. Applying their skills in a logical, well-organised manner, and identifying the main cause of the problem. To solve problems successfully, an engineer must also be able to listen to the ‘owner’ of the problem.


If they answer by saying things such as they:

  • Perform multiple quality assurance checks, and
  • Have their work supervised by registered engineers,


Then, you have found a team that pays ultra-careful attention to every aspect. 


All of these qualities are particularly important if you have a challenging block of land.


An engineer needs to know how to put their problem-solving and creativity skills to use and communicate these effectively with you.


For example, getting a soil test from an engineer will help you to figure out the stability of the ground you are building upon.


If the soil shows signs of:



These are all issues that might mean you need to readjust your plans, but your engineer should be able to:


  • Put their problem-solving skills to use so you can still go ahead with your development.


For example, if there is rock in your surface soil, excavation can be both difficult and rather costly, so:


  • The granny flat will need to be built out from the slope.


Can the Engineer be Placed at Fault With any Construction Errors?


No – there are many aspects to Construction, so it is important that you do your own research first.


This involves contacting your Council and finding out exactly what you need to be approved for your granny flat.


While an engineering report is important, it is just one of the:



After extensive research I was able to compile a list of recommended Engineers below:


List of Recommended Engineers in Each State


New South Wales









Western Australia



South Australia






Northern Territory



Australian Capital Territory





Structural engineers play a critical role in the development of your granny flat.


It’s part of their role to ensure that the:


  • Structural design of your granny flat is safe, resistant, durable, functional, and complies with Council and building regulations.
  • Granny flat will hold up to the stresses and forces that will be placed on it.


They will come to your site, assess your land, its’ conditions, and foundations, and provide you with a:


  • Stamped Engineering Plan (also called an Engineers Report).


You will not be approved to build your secondary dwelling from your local Council without this report, as it shows;


  • Your granny flat will be structurally sound.
  • The conditions of your land.
  • Strict guidelines on the materials you must use, ensuring it meets the standards of the Building Code of Australia (BCA).


As this report includes drawings that show all shapes, sizes, and forms of every part of your proposed granny flat, they will be accepted by your Council. The engineer will also provide you with technical advice on safe designs and construction.


It is important to have an experienced and knowledgeable engineer, particularly if you have a challenging block, such as one on sloping land, as;


  • They will be able to use their problem-solving skills so you can proceed with your building your granny flat within your budget.


It is also important to know that the role an engineer plays is highly important, as;


  • Granny Flat Designers will require the Engineers report from you.


Your architect or drafter will need the reports from you so they can start designing plans. It is also important to note that an engineer is not to blame if anything goes wrong during construction – perhaps it means plans have not been followed correctly.


This is why I suggest you do your research first and find out your Councils’ regulations for approval.