How Much Does a Home Extension Cost? (2023)

How Much Does a Home Extension Cost

A house extension is a far better option than moving to another home. At some point in life, it feels required to have a big house, whether it’s because of family growth, family distribution, a better future, or for renting purposes. Extending your home can solve half of your problems. If you are thinking of extending your house area, you should better understand the floor plan first. You need to understand which areas of your house need to be extended according to your personal requirements. Before planning for the house extension, you need to set a budget for better output. 

In this blog, we will explain the factors that affect home expansion costs, share insights into various extension types, and offer advice on how to properly manage your budget. So come plan a better expansion of your home with our detailed guide.

Types of House Extensions and their Cost

Types of House Extensions + Cost

Understanding the many types of house extensions and their expenses is the first step if you’re considering expanding your home but aren’t sure where to start. The extension may completely change the way you live, whether it’s by creating more room for your expanding family, a home office, or a stunning new living area. There are usually different options depending on your choices and requirements, whether you are living in a semi-detached or detached property. There are numerous types of house extensions available; we have prepared a list for each for better budget planning during home extensions. 

  • Single-Storey House Extension 

The most commonly followed extension is a single-storey extension by homeowners in Australia. This kind of extension will be used to add some extra space to your existing layout. The size and shape of the extension will be dependent on the current house design. By adding a single-storey extension, none of the house areas will seem wasted and underutilised. There are numerous ideas for single-storey extensions that can enhance the beauty of your house and maximise the space. If you want to add more adventure to your home, you can add home cinemas, gyms, playrooms, children’s nurseries, and much more. The average cost of this type of house extension lies between $1,600 per m2 and $3100 per m2. 

  • Double Storey Extension

A double-storey extension is used to multiply the spacing of your house and give you the best use of your property. You can have the same design you already have on your ground floor or you can have a different design on the same property. The double-storey extension allows you to use the house for rental purposes or for two families to live in one property. As it is a larger project than a single-storey addition, its cost will also be high. You need to budget accordingly. The average cost of a double-storey extension is $28,00 to $3,800 per m2. 

  • Conservatory House Extension

A conservatory is a type of house extension with glass walls and roofs to increase the space and value of your home. For this type of extension, you would require permission. This type of house extension is a more efficient option, providing a better level of thermal efficiency, which can help you save money and energy. You can use the conservatory extension in your living room, bedroom, kitchen, or porch area. The cost of this extension is somewhat between $5,000 – $30,000 per m2, but it varies according to the type of material used, its size, and its design. 

  • Wraparound Extension

A wraparound extension is a smart architectural choice that makes the most of the space that is available. It smoothly incorporates new sections into the current structure by expanding both the side and the back of your house. Since there is a sense of fluidity and openness created, this is the best option for people who wish to considerably expand their living area without adding a room or floor. $2,000 – $5,000 per m2 is the average cost people spend on this extension. A wraparound extension may make your ideal home a reality, whether you want a large kitchen and dining area that are bathed in natural light or an open-concept living area that can accommodate your expanding family. Incorporating large windows and sliding doors, which connect your indoor and outdoor spaces for a comfortable living environment, is another versatility it offers.

  • Garage Extension

Converting an unused garage into a living space is a practical and economical alternative for those who have one. Converting garages can create useful space because they are frequently used as storage facilities for clutter. The normal cost of such an extension is $5,000 to $15,000 per m2. A garage conversion can give you the practical space you require, whether you need an additional bedroom for visitors, a home office for remote work, or a playroom for the kids. Additionally, it reduces the need for exterior structural alterations to your home, making it a quicker and more affordable alternative to adding a brand-new extension. Converting your garage can increase the functionality of your home while also improving its value.

  • Basement Extension

Basements and cellars are frequently unlit, wet, and underused areas. However, they can be made into comfortable living spaces with the right layout and waterproofing. However, the cost of extension is generally high, ranging between $250,000 and $500,000. The benefit of basement extensions is that they can increase your home’s square footage without changing its exterior design. This area can be altered to meet a variety of requirements, such as adding bedrooms for an expanding family, building an entertainment room for watching movies in the evenings or constructing a home gym for your exercise regimen. In addition, the lower level can provide a peaceful retreat away from the bustle of the main living rooms for private home offices or artistic studios.

  • Backyard Extension

A backyard addition is a sort of house addition that entails extending your home’s living area outside into your backyard. It’s a common option for property owners who want to add space without changing the house’s front façade. The main goal of a backyard addition is to expand the amount of usable living space in your house. $15,00 to $4,500 per m2 is the average cost you need to pay for this. You can plan it to serve a variety of purposes, such as expanding the kitchen, establishing a comfortable family room, arranging a roomy dining area or even building a home office with a lovely view of your garden. The layout should suit your own requirements and way of life. Also for better better ventilation, you can use hog wire fence panels for your backyard rather than a casual fence to have better airflow within your backyard. Just make sure you’re not that exposed to your neighbors.

Types of Extension Approximate cost of extension
Single-storey extensions  $1,600 - $3,100 per m2
Double-storey extensions $28,00 - $3,800 per m2
Conservatory extensions $5,000 - $30,000 per m2
Wraparound Extension $2,000 - $5,000 per m2
Basement conversions $250,000 and $500,000
Basement conversions $250,000 and $500,000
Garage Extension $5,000 to $15,000 per m2

Note: All above-given extension costs are just estimates and can fluctuate as per owners’ requirements.

Factors that Influence the Cost of House Extension

Factors that Influence the Cost of House Extension

There are tons of reasons to extend your home. One of them is family growth, and you require more space; another is starting your own business, and you require office space to focus on your objectives. Fortunately, the solution to building a cost-effective house addition begins with very simple steps. The costs associated with home extensions can vary greatly based on a number of variables. Your ability to estimate and control the cost of your house extension project will depend on your ability to comprehend these aspects. Here are some cost-effective factors that can increase or decrease the cost of your house extension. 

  • Size and Complexity of the Project

One important aspect that affects pricing is the size of your home addition. This is the most common factor that influences the cost of a house extension. The larger the addition, the higher the total cost will be. This is the simple and common rule of extension. Larger square footage additions often cost more overall since they use more materials and labour. Furthermore, a big part is played by how complicated the design is. The complexity of the house extension can increase the cost of the extension and the number of people needed to complete the task. The more time and effort the house extension will take to complete, the more the cost will be extended. 

  • Design

If you want the cost of a house extension to remain low, it is better to choose simple and less time-consuming designs for your home. The more complex design will require a high volume of work, labour, and materials. It is likely better to keep the additional design uncomplicated to ensure a manageable budget. The most cost-effective and easy-to-design shape is a rectangle, which is highly recommended by most design experts. If you want to keep your house addition cost low, do yourself a huge favour by using a rectangular structure. Fancy windows with distinctive patterns, an exceptionally high ceiling, or detailed wall decorations all contribute to increasing the cost of house extensions. 

  • Building Permits

You need approval from your local government, sometimes known as a building permit, before you can begin building or extending your home. It’s like getting the go-ahead to start construction. These licences guarantee that your project complies with safety standards and laws. Wrap-around and double-story extensions are the best examples of this permit. If you want to get your house extension done without interruption, make sure to get building permits in advance. These permits are chargeable. If you don’t get it in the desired time, it will result in delaying the work and increasing labour costs. 

  • Labour Costs

The labour cost is the sum of money required to pay the individuals who will be building your house extension, such as contractors, home builders, and labourers. When creating the budget for your project, it is essential to be aware of these prices because they might change depending on a number of variables. The cost of labour as per daily wages will be the most significant part of the house extension cost calculation. Labour costs will be paid hourly in some areas of Australia. Different contractors charge their wages according to their own criteria.   

  • Material cost 

One of the most important choices you’ll have to make when designing a home extension is what materials to employ. Both the aesthetics and cost of your project might be considerably impacted by this decision. The premium materials can increase the overall cost of your home extension when compared to more economical alternatives. You can get suggestions about materials from your architect and also get references from them. The construction material that will be required for the house extension needs to be shipped to your home. The shipment of these materials is also chargeable and adds to the cost of the house extension.  

  • Contractor Services

Hiring a contractor for the construction project might seem daunting and expensive, but the best thing about hiring a contractor is that it will be their responsibility to provide end-to-end construction. The cost of hiring a highly qualified and experienced contractor is frequently higher. However, their experience can be a benefit in ensuring that the project works smoothly, complies with quality standards, and averts costly errors. The usual cost for a contractor is $150 per hour. The general contractors will purchase materials, complete your construction in a limited time, coordinate with the subcontractors and delivery persons, and obtain permits on their own without disturbing you. 

  • Cleanup

A house extension is all about breaking and constructing new designs, and it’s obvious to have dirt and debris while reconstructing the already constructed place. To dump away debris, cleaning up floors, walls, counters, and windows and throwing extra material will be included in the house clean up. Its usual cost will be $500 to $550 for post-construction cleaning services. You should also include this in your house extension cost as it will directly and indirectly, by both means, affect the final cost.

How To Minimise The Cost Of House Extensions

House Extension Cost As Per Extension Type

Extensions might be a bit expensive, but with the right guidelines, you can cut unexpected expenses that can pop up in your budget. When you plan your things in the right manner, you can make your way towards saving some money. Careful planning, wise decision-making, and effective resource management are necessary to keep the expense of house extensions to a minimum. Here are some tips to help you stay within your home addition project’s budget:

  • Set a Realistic Budget

To begin, evaluate your financial status and decide how much you can and are willing to invest in your home addition. Setting a realistic budget that accounts for every component of the project, such as construction, permits, materials, and any unforeseen expenses, is essential. You’ll be able to make informed judgements throughout the project and prevent overspending if you start with a defined budget.

  • Proper Planning

Spend some time on thorough planning. Your demands and goals for the extension should be specified in detail. Think about things like the space’s use, the number of rooms, and any unique characteristics you want. Your likelihood of running into expensive alterations or additions during construction decreases with the level of depth and care you put into your plan.

  • Compare Different Quotes

Request many quotations from different contractors, then carefully compare them. To achieve an appropriate comparison, make sure that each quote refers to the same materials and scope of work. Consider the reputation, experience, and dependability of the contractors in addition to the cost.

  • Try DIY Where Possible

Wherever possible, try to do it yourself (DIY) to cut labour costs. If you have the knowledge and expertise to do it yourself (DIY), consider doing it. You might be able to do some simple carpentry, painting, or landscaping. However, exercise caution when taking on activities you are unsure about because errors might ultimately result in increased charges.

  • Reuse and Recycling

Look for ways to include recycled or reused materials in your extension or consider reusing components from your current area. Salvaging doors, windows, or flooring can dramatically lower your project’s material costs while enhancing its character.

  • Check Your Contract

The most important step that you should follow while getting contracted with builders is to read all clauses carefully. Make sure that builders have provided a full-cost quote in the contract. Never start building an extension with a tight contract. You can do anything to avoid surprises from the contractors. 

  • Get To Know Your Materials

It’s not necessary that you only buy the materials or brands suggested by professional architects or experts. You can do your own research and use materials that are within your budget without compromising the quality. 

  • Timing Matters

Take your project’s timing into account. Contractors may offer lower rates during slow periods when there is less demand for their services because the need for construction work frequently varies. Saving money can result from scheduling your extension during a less busy time.

  • Stick to the Original Plan

Once work has started, stay true to your original plan to prevent scope creep. You should not start making other layouts or changes to your plan once the construction process has begun. After the project has begun, changes and additions may need revisions to already completed work and supplies, which can be expensive. So it’s better to avoid them and follow the original plan.

Benefits Of House Extension

Benefits Of House Extension

House extensions are a common option for increasing living space and improving a home’s functionality because they provide several advantages to homeowners. Here are some major advantages to home additions:

Increased Living Space: House extensions give you more square footage, enabling you to build more space for your family’s requirements. Extensions provide the room to meet your needs, whether you need more bedrooms, a bigger kitchen, a home office, or a larger living space.

Enhanced Functionality: Home additions can be tailored to your unique requirements and way of life. You have the freedom to customise the area to your tastes, making it more practical and suited to your family’s activities.

Increased Home Value: A well-planned and built house addition can dramatically raise the market value of your home. If you add bedrooms, bathrooms, or other desirable additions, it may increase your home’s appeal to potential purchasers.

Avoiding the Hassle of Moving: A house extension enables you to remain in your existing area while obtaining the extra room you require without having to deal with the hassle and expense of buying a new home and moving.

Cost-Effective: Often, expanding your current home is less expensive than purchasing a larger home. It avoids charges like agent commissions, closing fees, and moving costs that are related to real estate transactions.

Energy Efficiency: Energy-efficient features, such as improved insulation, eco-friendly materials, and energy-efficient windows and doors, can be incorporated into contemporary home additions to help lower utility costs.

Increased Natural Light: To maximise natural light and create a brighter and more pleasant living environment, extensions may include wide windows, skylights, or glass doors.


Are you ready to get started working on your home extension project? Still, if you are not sure which type of extension would be best for your property and feel helpless, then you should contact a specialised architect. They can suggest something great and help you find the solution to get the most out of the budget-friendly house extension. A home extension’s price might vary significantly based on a number of variables. The cost of the expansion will be greatly influenced by the size of the addition, the materials used, labour rates, and your location. To make sure you have an accurate sense of the prices involved, it’s crucial to carefully plan your budget and obtain various quotations from contractors.

Keep in mind that while house additions might be pricey, they can also significantly increase the value of your property and enhance your quality of life. A home addition can therefore be a wise investment in the value of your home and the comfort of your family’s future, with careful planning and budgeting.

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