How Much Does a Home Extension Cost in 2023? Here are 7 Important Factors

January 12, 2023

As your family grows, you may find yourself requiring more usable space. Planning to renovate the home you love is one of the most exciting and most personal projects a person can undertake. However, there is no set formula for calculating the exact home extension cost - every home improvement project is as unique as the homeowner embarking on it. Here are 7 important factors to consider when investigating your home extension cost in 2023:

New construction of beam construction house framed the ground up framing against a blue sky


Are you planning to add an ­extra storey to extend your home?

When investigating the costs of home extensions and renovations, in order to get an accurate quote, it is a good idea to initially map out what your requirements are. One major factor to consider is whether you need to add another storey to your home, and to find out if this is even structurally possible for the existing architecture of your building. Adding another storey or extending the floorplan to your home can open up the possibility of extra costs such as surveying fees, costs for local council development application approval, and more.

While it may sound counterintuitive, larger Home Extensions can actually be more economical in terms of price per square metre.



How much extra space do you need in square metres?

According to a Housing Industry Association (HIA) report, approximately half of all renovations in Australia are valued between $40,000 to $200,000. When you break it down to per square metre, home extension costs average around $2,000 - $4,000 per square metre according to an article published by Better Homes and Gardens online.

Whether you are looking to improve your lifestyle, increase the value of your property or are mainly intending to update the style and exterior of your home, when estimating costs it is beneficial to get a rough idea of just how much space you will need to renovate for your family’s future.



What materials are you planning to use for your home extension?

The type and quality of materials you choose will naturally affect your house extension cost. Different materials such as timber, brick, glass and vinyl all have varying prices. For example, according to an article by Budget Direct, a single-floor extension using vinyl can be around 35 per cent cheaper than using timber.

Our longevity in the industry has allowed Cubitt’s to source the best quality materials from world-class suppliers, at affordable prices for our customers. We partner with some of the biggest brands in construction such as COLORBOND®, Weathertex, Polytec, James Hardie and Caesarstone.

Beam stick built frame of a new house under construction of the wooden house


What is the functionality of the extra space you want to build?

If you think the functionality of the rooms won’t impact the building cost, think again! If you need to add a bathroom or kitchen, this will increase your costs, as these rooms are the most expensive to build. This is due to the plumbing work, gas and piping installation costs, as well as any appliances and fittings required. Adding a bathroom or ensuite will add between $17,000 - $38,000 to your price, adding a kitchen ranges between $15,000 - $50,000 while adding a laundry can add between $6,000 - $18,000 to your project price, according to OpenAgent.

Alternatively, if you are looking to improve your home with an additional living area or added bedrooms, these rooms will be cheaper to build. While home extensions cost thousands of dollars, it can be reassuring to remember this cost is an investment in your property and is designed to improve your family’s lifestyle. Better Homes and Gardens states that home extensions can increase the value of your home by up to 10 times the cost of renovation.



Have you accounted for HVAC (Heating, Ventilation and Air-Conditioning)?

Heating, insulation and cooling are all necessary for comfortable everyday living, so it’s important to include the cost of an air-conditioner, ceiling fans, any additional heating requirements and high-quality insulation into your costs.

One tip is to check the Minimum Energy Performance Standards (or MEPS) to see what the energy efficiency is of the air conditioner you intend to purchase, as this will help reduce your total power cost per year.

At Cubitt’s, we use stylish, energy-efficient and durable materials to help keep your power costs low.



What kind of land are you building on?

Is your property on a flat, sloping or narrow block of land? This is a factor that will impact your cost, and could even impact your choice of builder. Having handpicked the best tradesmen in the industry, Cubitt’s have the expertise necessary to build on difficult blocks of land. You may also need to consider if there is much demolition work that needs to be done, if any excavation work is required, and if there is any hazardous material that needs to be removed such as asbestos. These are all elements that can add to your cost.



What is the quality of the builder you want to complete the work?

While every builder can build a roof over your head, the level of quality may differ greatly. When it comes to selecting a builder, the cheapest quote is not necessarily the best. We’ve all heard the horror stories of people’s homes being left unfinished, walls cracking just months after construction has finished, dodgy materials being used or customers being overwhelmed with extra costs not initially disclosed by the builder. For this reason, it is advisable to be cautious of builders who are considerably cheaper than their competitors.

Your home is your family’s future, and building a quality home built just for you is perhaps one of the most personal and important endeavours of your life. Make sure you do your research and choose a professional builder who holds a current Builder’s Licence for the state you live in, offers Home Owner’s Warranty Insurance, and is transparent with you about their building process as well as what materials will be used.

With over 25 years’ experience building customers their dream home extensions throughout NSW and the ACT, Cubitt’s Granny Flats and Home Extensions are specialists in mid-range home extensions for growing families, and represent the best value for money in market.

As a family-owned and operated business, at Cubitt’s we believe in providing a stress-free experience for every customer. This is why we offer an award-winning customer service team, and a dedicated point of contact to keep you informed at every step of the journey. We deliver projects on time and within budget, with no hidden fees or post-contract changes. We even take care of the council approvals process for you, with experienced council planning and drafting teams who understand the complexities of working with different councils throughout NSW and the ACT.

Contact our experienced sales and design consultants on 1300 721 150 for more information and to find out how to make your dream home extension a reality.



Guide to renovation costs
Australian Renovation Cost Guide
Extend or move: How much does an extension cost?
Home extensions 101

What a renovation looks like with Cubitt’s

Here at Cubitt’s, we’ve built our business around home extensions and renovations. We’ve completed more than 300 extensions across Sydney, Newcastle, Wollongong, Canberra and beyond - we love seeing a house transform into a dream home, which is why we’re considered one of the leading renovation teams on Australia’s east coast!

Reinvent your home with Cubitt’s - give us a call on 1300 721 150 for an obligation-free consultation today!


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About Kate Cubitt

Kate is Managing Director of Cubitt's. She is an experienced company director, avid investor and keen to share the financial insight she's gained being a female leader in the building industry.