Granny Flat

Baulkham Hills


about this project

Our currently owned investment property included a 40-year-old house with three bedrooms and two bathrooms, set on a 700m2 parcel of land. The rent was a modest $550 per week for a $1.2 million dollar property at Baulkham Hills. Land tax was now payable as the property's value went up. But this increase was not reflected in the weekly rental. To add to the issues was a 25-year-old swimming pool that had once encouraged tenants and good rents. But running costs in the winter and the power costs to operate pool pumps has in the latter years become a deterrent to many prospective families. Tenants in general do not want to look after gardens, lawns and pools.

To increase the rental viability of the property, we would have to complete one of the following options:

1. Knock down and re-build a larger and more modern home at a considerable expense, ($400k to obtain an increase of $200 per week).

2. Complete an expensive extension that would increase the weekly rental by a modest amount ($150k to obtain and increase of $100/week).

3. Add a Granny flat for a separate rental ($200k including all gardens, paths, driveway, fencing, electrical connections and granny flat for an additional income or $350 per week).

4. Relatively quick comparison of costs versus income. This had determined the granny flat as the most cost effective and best return option.

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  • for-project
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  • 62 Glanmire Road, Baulkham Hills


  • No loss of income as the house was rented while the granny flat was being built. A builders fence with power board and tap was installed to separate the tenant from the building site.
  • Slightly lesser rental revenue on the house because of the loss of the pool (-$50 per week) and some of the back yard area. But it was well compensated by the second rental income from the granny flat. The tenant was compensated with an improved outdoor area that’s smaller and easier to maintain.
  • A decrease in maintenance costs without the pool in the property. It also reduced water and power consumption costs for the tenant.
  • Two rental incomes from one property and no increase in land tax costs.
  • Only one cost for rates (but there’s a small charge per year for the additional rubbish bin).
  • You can claim depreciation on the granny flat’s fixtures and fittings.
  • Construction of the Granny flat including approvals were completed in approximately 9 months. Thus, making it a relatively quick “turn around” on investment.


Design by the Inhouse Group was flexible allowing for special inclusions:

  1. 1.5 size garage to provide additional storage
  2. Inclusion of the laundry in the garage to provide more space in the bathroom and allow for a linen press
  3. 25m2 alfresco
  4. Edge beam from the garage to the granny flat to allow for construction on a sloping site
  5. Vaulted ceilings in the living area to provide a spacious appearance
  6. 3 steps in sliding door from living area to the alfresco to open the space up for entertaining
  7. Easily upgraded finishes without extravagant increases in costs for additional, GPO’s, light fittings, stone bench top, dish washer, recess in the shower, recess mirror cabinet and the list goes on. Many of these items were offered at cost for materials and labour.
  8. Contractor trades separate to the building contract with Inhouse Granny Flats were offered and found to be reliable and cost efficient for drive way and paths, stone wall, fencing etc have been invaluable to finishing off the property.
Testimonial from Home owners
  • The expertise of In-house Granny-Flat became evident very quickly. Both Tony and George, and particularly the lovely girls in the office were exceptional to deal with. They made everything seem so effortless. I was impressed with their ability to communicate effectively and address detailed site management and construction issues with professionalism and ease.

    A special shout out to George the Project Manager, who did a great job at making sure I was kept well informed of every aspect of the job and every member of the contractors, was always courteous and very hard working. George went beyond the duty of call to just building a granny flat.

    George did so much extra work and accommodated so much for me without any hesitation. Whatever I needed or asked for was done. The time it took to commence and hand over my granny flat to say the least, extraordinary. Not a single day was wasted everything was timed perfectly.

    The girls are a gem! They were always ready to accommodate any changes to the original design, resolve difficult construction details effectively and happily. They are reliable, trustworthy and genuine. The way they handled everything was very impressive. They always listen, and are consistently well-organised and professional.

    It certainly is nice to know such a reliable and genuine company like In-House Granny-Flat does exist. I have and will continue to recommend your fine company to others since your workmanship as well as the people you have working for you are top rate, and your prices are fair. And to top it off the quality of work was excellent.

    A very happy little vegemite J

    M. Jaber

    Eastern Creek

  • Inhouse’s service was absolutely fantastic! Every part of the process went like clockwork and the finishes were perfect. The construction process ran like a factory. When one team of tradesmen were finished, the next came to complete and George, the project manager, was there to oversee the lot.

    Finished product rating: 100%


    Baulkham Hills

  • Benefits from Inhouse: “My granny flat received a lot of praise from friends! They were amazed how quickly you have built them.”
    Comments: “I am most grateful… even when my funds were not on time to pay, you were patient and very kind to me, thanks.”
    “Professional and kind attitudes!”


    Warwick Farm

  • How do you rate Inhouse’s customer service:
    “The staff there are tremendously nice, they helped me even when I was having difficulty with my council.”
    “Highly recommended.”



  • Very fast construction. Everything finished in time for my mother law to come from overseas.



  • Could not be happier.



  • The Inhouse construction program was organised and adhered to allowing for completion in a timely manner. Occupancy documents were provided by the private certifier to the council directly.

    Onsite construction workers were polite and respectful of the tenant in the adjacent house. The quality of the finishes is excellent and any minor defects were promptly attended to by our helpful project manager Steve (who was always available to contact by mobile phone).

    Payment schedules were clear and concise, with remittance advice for tax records provided promptly. The office staff were polite and offered explanations for any questions asked. Choices in finishes such as tiles, kitchen and bathroom fixtures and fittings, paint and blind colours were offered in a sensible way with all samples able to be seen together. Alliances were provided with all instruction manuals and warranty details.

    Overall, the costing, design, preparation of the site, construction of the granny flat and completion by all trades have been a very satisfactory experience.

    We have regretted dealing with (Other Contractor/Competitor). The delay in having meters fitted in the existing house power board for the granny flat supply has caused the only major delay we have experienced. This has been due to the influences of (Other Contractor/Competitor) and inexperience on our behalf. We would recommend that if you are intending to work with Inhouse Granny Flats that you leave this work under their contract.


    Baulkham Hills

the process

  • 1. Getting a Quote

    1. Getting a Quote

    The first step to building a granny flat is an enquiry. When you call or email us, we will send you a free information pack so you get a better understanding of what we do. From there, our qualified builder will inspect your backyard free of charge to check the area and discuss your needs and requirements. Our sales representative will then send you a fee proposal, which outlines the necessary requirements for your granny flat as well as its inclusions and overall price.

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  • 2. Flats and drawing stage

    2. Flats and drawing stage

    Once you have accepted the terms and conditions of our fee proposal, provided us with a 10.7 planning certificate (formally known as 149 Certificate) from council, a sewer diagram and you have paid a deposit, we will organise for a surveyor to carry out a site survey on your property.
    Once we have received your survey our qualified Inhouse design team will then draw up a concept floor plan and organise a personalised meeting to sit down with you to ensure your needs are met and any design alterations are made.
    Once you are happy, we will proceed to start your approval with a private certifier or via council.

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  • 3. Contracts

    3. Contracts

    Once your completed approval has been issued by a Private Certifier or Council, we will ask you to sign a Fair Trading Home Building Contract and organise your Home Owner’s Warranty. We will invite you in for a meeting to select all the materials and colours for your granny flat from our wide range of selections available in our showroom.

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  • 4. Construction

    4. Construction

    We will schedule your project to start and order all materials you have selected for the build.
    We will then be on-site organising earthworks, excavation and piering to prepare for the slab.
    You will be appointed a site foreman who will guide and update you throughout the construction until the handover is complete.
    At Inhouse, we know that this investment is important to you and we do our best to finish construction as soon as possible while not compromising the quality of your building. Your brand new granny flat will be completed within 12 -16 weeks.

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