About Us

Experience Inhouse Granny Flat's 25 years of expertise in building affordable and high-quality granny flats throughout Sydney, providing property investors with increased rental income and families with extended living space.

Inhouse Granny Flats – Your Trusted Sydney Granny Flat Builder

Inhouse Granny Flats is an established company with over 25 years of experience in the construction industry. We are builders located in Castle Hill who specialise in the design, approval and construction of granny flats in all Sydney areas. Granny flats allow property investors to increase rental income. It also provides affordable rental housing or extended home for many families.

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State of the art showroom

Our state-of-the-art showroom is one of a kind in the current granny flat market. We display the complete range of our standard inclusions. It allows our clients to gain a better understanding of what Inhouse Granny Flat is offering in comparison to other builders.

Experienced Team

From your first obligation FREE on-site consultation, all the way through to design, approvals and construction, you can rest assured that you will have the most experienced team working on your granny flat.

Our entire staff is committed to providing you with quality advice and a personalised service. Our labourers, bricklayers, concreters, plumbers, excavators, carpenters, electricians, painters, cleaners, builders, project managers, receptionists, designers, engineers, and architects will be on deck and ready to accommodate your every need.


Our Inhouse crew consists of:

  • Experienced Granny Flat Builder
  • Qualified Granny Flat Designer
  • Approvals Co-ordinator
  • Construction Manager
  • Account’s Managers
  • Granny Flat Site Supervisors
  • Granny Flat Consultant
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The Inhouse Granny Flats crew has a reputation for being one of the best Granny Flat builders in Sydney. We source our premium quality materials from Australian suppliers and we deliver our finished products to your satisfaction. Whatever your reason is for wanting to build a flat, Inhouse Granny Flats can provide you with a turnkey home solution that will result in a high-quality end product. With a selection of designs to choose from, ranging in sizes from 60sqm up to 80 sqm inclusive of a garage/ alfresco, we have standard granny flat designs or custom designs that can be tailored to better suit your property.


Enjoyable building experience

At Inhouse Granny Flats, we focus on more than just the price, although we do understand that money is an important factor when making a decision on building a granny flat. From your initial enquiry through to handing over the keys, we will guarantee to make it a hassle-free operation and an enjoyable building experience.

So if you’re ready to build your granny flat, contact us today and let us handle 100 % of the process. It’s all of this and more that reflect Inhouse Granny Flats’ excellent customer service and exceptional delivery.


Do you have a property in mind to buy?



  • Ensure feasibility of investment
  • Avoid wasting time and money
  • Determine if a granny flat can be built before purchasing the property


  • Customise granny flat design
  • Ensure compliance with local council regulations
  • Assess land characteristics that can impact construction


  • Optimise investment
  • Increase rental income
  • Add value to your property
  • Provide additional living space for family or guests

Open Home Registration

Register with us today and receive a weekly alert regarding future granny flat showings in your area.


Trusted by Hundreds of Clients


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