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 home. At one point in life, it feels required to have a big house, whether it’s because of family growth, family distribution, for 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. Understanding which area of your house you need to extend according to your personal requirements. Before planning for the house extension you need to set a budget for better output. 

The fact is that the more you put off your house extension plans, the more you will end up paying the extra cost, and the cost of materials and labor will keep rising day by day. Although the cost of your house extension will be depending on the type of material you use and the type of extension you want.

Types of House Extensions + Cost

Types of House Extensions + CostThere are usually different options depending on the choice and requirements of whether you are living in a semi-detached or detached property. The options will be provided by the house extension experts. Once they understand the type of extension that is suitable for your home, they will be able to plan your house extension process. There are numerous types of house extensions available, we have prepared a list for each. 

  • Single-Story House Extension 

The most commonly followed extension is a single-story extension by homeowners. 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. The single-story extension is popular among Australians. By adding a single-story extension, none of the house areas will seem wasted and underutilized. There are numerous ideas of single-story extensions that can enhance the beauty of your house and bring the space to utilization. If you want to add more adventure to your home you can add home cinemas, gyms, playrooms, children’s nurseries, and much more.

  • Wrap-Around Extension

The wraparound extension is the most convenient and inexpensive way to add as much space to your property. Having a new space right near your home that you can use as per your requirement can fulfill your needs.  You can add an extra bedroom or open kitchen to your home. As compared to other house extensions, wraparound extension is the most popular type of expression with a wide range of positive experiences.

  • Conservatory House Extension

A conservatory is a house extension type with glass walls and roofs to increase the space and value of your home. In 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 with your money and energy. You can use the conservatory extension in your living room, bedroom, kitchen, or porch area.

  • Double Storey Extension

A double-story extension is used to multiply the spacing of your house and give you the best usage 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-story extension allows you to use the house for renting purposes or for two families to live in one property.

  • Basement Conversions

Basement conversion is a bit expensive extension idea. But it is best to utilize the space. Digging out a brand new basement can help you to utilize your house space but you need to be aware of some circumstances that you can go through while making a basement. You need to take care of pipelines that have been connected under the floor and the condition of the site. 

House Extension Cost As Per Extension Type 

Types of Extension Approximate cost of extension
Single-storey extensions  $2,100 to $ 3,100 per m2
Double-storey extensions $3,100 to $ 4,100 per m2 
Conservatory extensions $5,000 and $30,000
Basement conversions $250,000 and $500,000
Wrap-Around Extension $2000-$4000

Note: All above given extension costs are just estimated costs and can fluctuate as per owners requirement. 

Factors that Influence the Cost of  House Extension

Factors that Influence the Cost of House ExtensionThere are tons of reasons for extending your home. One of them is family growth and you need more space or you might be starting up your own business and need office space to focus on your goals. Fortunately, the solution to building a cost-effective house addition begins with very simple steps. Here are some cost-effective factors that can increase or decrease the cost of your house extension. These are not only the issues that can affect the cost, rather they can have the most influence on your total project cost. 

  • Size

This is the most common factor that influences the cost of house extension. The cost of size addiction will be per square foot. This is not possible to clarify this thing properly. Every house addition has a different set of needs, challenges, and requirements. These differences make the project cost estimation a bit complex. But the larger addition, the higher the total cost will be the simple and common rule of extension. 

  • Design

If you want the cost of 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, labor, and materials. It is likely better to keep the additional design uncomplicated to ensure a manageable budget. The cost-effective and easy-to-design shape is a rectangle, highly recommended by most design experts. If you want to keep your house addition cost low, do yourself a huge favor by using a rectangular structure.  

  • Building Permits

In some extension cases, getting building permits is compulsory before initiating construction. Wrap-around and double-story extensions are the best example of this permit. If you want to get your house extension without any interruption makes sure to get building permits in advance. 

  • Labour Costs

The cost of labor as per daily wages will be the most considerable part of the house extension cost calculation. Labor costs will be paid hourly in some areas of Australia. Different contractors charge their wages as per their own criteria. 

  • Complexity

The complexity of the house extension can increase the cost of the extension and the number of manpower in order to complete the task. The more time and effort the house extension will take to complete, the more the cost will be extended. 

  • Shipping Costs

The construction material that will be required for the house extension needs to be shipped to your home. The shipment of these materials will impact the overall cost of your house addition.

  • Material cost 

Being a homeowner everyone dreams to get the best and long-term results once they renovate their home. No one would be able to spend money and time so early on repairs right after having a house renovations or extension. We would suggest you go with high-quality materials whether it’s a bit expensive but they will give you satisfactory results. You can get suggestions about material from your architecture and also get references from them. 

  • 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 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

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 house clean up. Its usual cost will be $500 to $550 for post-construction cleaning service.    

Also read: Top 5 Renovations Ideas That Add Immense Value To Your House

Additional Costs and Considerations

  • Roof Framing and Materials

In order to have a house safe, secure, and liveable that protects from the weather, don’t take lightly the quality of roof material. Roof framing approximate costs of roof material are given below.

Roof Framing and Materials Approximate Cost (per sq. ft)
Roof framing costs  $700 to $900
Roof materials cost $500 to $5,000 for 100 square feet 
Shingles $80 to $100 per square foot
Steel roofing costs $75 and $350 per square
  • Drywall Ceiling and Walls

In some climates like the winter season, after construction it would still be unfinished without having drywalls; it is the most common requirement to cover up insulation and electrical wiring. To drywalls, you need expectedly to pay $450 to $550. It will be around $2 to $4 per sq. ft. to install drywall.

  • Doors and Windows

With the purpose of natural light and air the common preference when adding to a house. Windows can shake your budget by increasing costs with their size or number. It can approximately come with $235 to install the window. If you want to get a customized window you would need to pay $2,500. 

  • Electrical Installations

Right after completing the house construction it is important to install electric wiring in order to check that you have light and power for all the electronic items. Best electricians can charge $40 to $100 per hour for a complete wiring process.   

  • Interior Fixtures And Fittings

The exceptional cost of house extension depends on your choice and taste. The cost of carpet, floorboard, curtains, and rolling blinds on your windows will be added with other fittings like your door handle, lamps, paint, or wallpaper. If you are constructing a new bathroom the cost of sinks, baths, toilets, and showers will be included in the cost of house extensions. 

  • Plumbing

If you add a bedroom or expand your living space you might not need to get help from the best plumber. But if you are expanding the kitchen or bathroom area then you would definitely require a plumber, the approximate cost of a plumber will be $45 to $150 per hour. They will install all the water connections for the kitchen and bathroom. 

How To Minimize The Cost Of House Extensions

House Extension Cost As Per Extension TypeExtensions might be a bit expensive, but with the right guidelines, you can cut costs from unexpected expenses that can pop up your budget. 

  • 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. 

  • Compare Suppliers

At every step of construction you should be extra aware of the upcoming challenges. From the finding of the contractor till the end, don’t go with the first quotation make sure to get 4-6 quotes from different suppliers. We are suggesting this tip not only that you will find a cheap contractor, but it’s also to find people who offer value, quality, and trust end-to-end reliable services. 

  • Get To Know Your Materials

There are a number of steps where you can save money when it comes to purchasing building materials. For instance, if your architect suggests installing a slate roof, the cost difference between synthetic slate (20p per slab) and Welsh slate (1.50p per slab) might be a total of thousands of dollars. You should be aware while buying materials.

Not every time is necessary to get the best and most expensive. Sometimes you can choose convenient and cost-effective material as well.


Are you ready to get started working on your home extension project? Still, if you are not sure which type of extension would be the best for your property, and feeling helpless then you should contact the architect specialized for your house extension to suggest you something great and help you to get the solution to get the most out of the budget-friendly house extension. 

To make sure that your house extension costs will stay within your budget, you should better take steps with planning and plotting. First, hire a professional architects. Hiring a team of expert renovators will help you to get superior designs and quality construction, and additional advantages like better deals on materials. Because they interact with suppliers on a regular basis. Furthermore, the best architecture will save you from the hassle of visiting from one store to another.

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