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How much does home extension cost?

home extension cost

When newlyweds look to buy a new house, they normally will settle for a house that fits the following criteria: budget, location and existing condition.

The more a family grows, the problem of insufficient space will become an issue. One good solution for this problem is a home extension. Just like in any other renovation-related jobs, most couple’s concern lies in one question and that is ‘how much does a home extension cost?’

To determine the home extension cost, you must consider several factors:

Site details

When you talk to a home builder, they will start by asking you to describe your home space such as ‘Do you have available space for their equipment or trucks?’ and ‘What type of ground your housing lot has – flat, steep or slight fall?’  

It’s ideal to answer the questions as descriptive as possible because this is the builder’s way to know the accessibility of your housing lot.

Note: Builders will not give any quote on this consultation.

Extension Works

This is the part where the home extension cost starts to pile up as this contains all the jobs you need. Builders may ask you a series of questions that can help them come up with a reliable quote. These questions can be any of the following:

Where will the extension site be?

The first contributing factor when determining the home extension cost is the place where you want the extension to be. Do you want to place it on the ground or second floor? Each floor will have a different cost.

If the extension will be placed on the ground floor, the home extension cost may range between $1,350 up to $3,875 per square metre. While if on the second floor, the home extension cost may range between $3,150 up to $5,812 per square metre.

What is the size of the new home extension?

After determining where you want to place the extension, the next thing you need to consider is its size. The minimum size of a home extension ranges from 20 square metres up to 150 square metres.

What type of home extension do you want?

This is the most interesting question for builders because this is where you will determine the extension’s function. There are different types of home extension, but the most favourite are the following:

  • Basement

Basement is one of the versatile household rooms because you can use it in different ways. You can transform it as a man cave for the husband, a craft room for the mums or playroom for the kids. The initial home extension cost for a basement is $100,000. But this will increase if there are additional jobs included like an excavation.

The home extension cost of the basement with excavation ranges from $250,000 up to $500,000. Note: Materials, size, and design are already included on the cost.

  • Kitchen

The kitchen is the busiest area of the house. Once your family grows, you will need more space for foot traffic and strollers. The initial home extension cost for a kitchen may range between $10,000 up to $22,000. This range is ideal for homeowners on a strict budget and extension housing size of 20 to 80 square metres.

For a larger-size extension, the initial home extension cost may range between $35,000 and up. Please note that not all jobs are included in that home extension cost. The only jobs that are included in the cost are the installation of new electricity lines and plumbing pipes.

  • Garage

The home extension cost for the garage type will depend on the level of work. If the extension space already has a roof and walls, you can expect to pay somewhere between $7,000 to $20,000. But if the builder will start from scratch with complex or high-end designs, the home extension cost may range from $25,000 and $50,000.

  • Loft

The loft is the most comfortable option for homeowners, but this can also be expensive. A loft needs several jobs just for it to be liveable like roofing, electrical safety, and effective drainage. The home extension cost for this type may range between $1,500 to $2,200 per square metre for a basic design and $2,500+ per square metre for a high-end design.

What materials do you prefer to use?

After identifying your preferred type of home extension, the next thing you must do is canvass for materials. For a house façade, there are three options:

    • Brick – $3.50 to $10 per square foot or $4,000 to $15,000 with installation fee included.
    • Rendered – $30 to $60 per square metre or $10,000 to $20,000 with installation fee included.
  • Glass – $40 to $320 per square metre. This includes glazing and installation jobs.

Other work included

The final factor to consider in determining the home extension cost is the additional work. Does the extension include jobs like excavation or demolition? If yes, what’s the level of work – minor, average or extensive?

One way to find out whether you need these jobs or not is by inspecting the condition of the working area. If it is empty and untouched you will be needing excavation, and this may cost $500 for small jobs and $8,000 for a large-sized project. While for demolition job, if there’s a damaged structure built on the working area. This may cost between $10,000 and $80,000.

Featured Photo Courtesy of PublicDomainPictures via Pixabay


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