What does a whirlybird cost to install?

Summer in Australia can be an uncomfortably warm time if you don’t live in a home with air conditioning. While it may not be the solution to a hot house, installing a roof ventilator (also known as a whirlybird) could be a relatively affordable way of managing the internal temperature. Even if your house is air conditioned, a whirlybird – or several, depending on the size of the area – could come in handy by speeding up the process of cooling.

What is a whirlybird?

A whirlybird is a small cylindrical dome attached to the roof of a building, with numerous ‘fins’ allowing it to spin. As it rotates, a whirlybird creates a vacuum which sucks warm air up and out of a roof cavity (the space in-between your highest ceiling and the top of your roof). Some whirlybirds are mechanically driven and can turn continuously, while others require wind to operate.

How much does a whirlybird cost?

Whirlybirds themselves are not particularly expensive compared to having air conditioning installed. At time of writing, Bunnings’ online store offers a wide range of whirlybirds, with prices ranging from $74 to $231 for wind-driven models, and upwards of $1,600 for top of the line mechanical ones.

Are whirlybirds really effective?

It’s important to note that a whirlybird doesn’t offer the direct cooling effect that an air conditioner or ceiling fan might. Where an air conditioner cools a room by pumping cold air into it, and a ceiling fan can help cool the occupants by creating a breeze, a whirlybird generally only serves to remove warm air from the uppermost part of a home.

However, a whirlybird can still contribute to keeping your home cooler in the warm months. It can help to prevent heat transferring from the air trapped in the roof cavity to the ceiling. This may limit the extent to which your home can heat up and reduce reliance on your air conditioning system (if you have one), which could save you energy and money.

A whirlybird may also prevent the accumulation of humid air, and subsequently ensure that moisture doesn’t build up in your roof cavity, which can prevent the growth of mould and/or mildew.

What does it cost to install a whirlybird yourself?

If you’re planning on installing the whirlybird yourself, purchasing it will be your sole expense, other than buying any necessary tools to install. Depending on what your roof is made from, you may need to drill a hole in it in order to perform the installation. You may also require a hammer, screwdriver, and elbow-high safety gloves.

If you plan on going the DIY route, it’s very important to bear in mind any safety implications of carrying out a job like this by yourself.  Be mindful of falling or inadvertently coming into contact with electrical wires. It’s also important to take care not to damage your roof in the process of installation, as this could lead to even greater expense.

While having your whirlybird professionally installed may seem like a more expensive option, it could potentially save you from damaging your roof – or worse, injuring yourself.

How much does it cost to have a whirlybird installed?

If you hire a professional to install your whirlybird or whirlybirds for you, the total cost of their services will depend on whether they’re supplying and installing the unit, or just installing a whirlybird that you’ve already purchased.

To give you an approximate idea of what you might pay, the Sydney Roof Doctor – a gutter cleaning and roof maintenance specialist – charges the following amounts for the supply and installation of ‘regular’ (e.g. non-mechanical) whirlybirds:

• $519 for one whirlybird
• $859 for two whirlybirds
• $1089 for three whirlybirds
• $1299 for four whirlybirds

The amount you end up paying for installation may be influenced by what your roof is made of, how easy it is to access, and how far the contractor has to travel for the job. It could help to obtain quotes from several different contractors to get a sense of what your options are and to avoid paying more than you need to. Regardless of who installs your whirlybird(s), you will generally pay less per whirlybird the more you have installed.

How many whirlybirds do I need?

You may assume that one whirlybird is all you’ll need, but depending on the size of your home, you may need as many as four.

According to Roof Vents Australia:

• A house with 2-3 bedrooms will generally need two whirlybirds.
• A house with 3-4 bedrooms will generally need three whirlybirds.
• A house with 4-5 bedrooms will generally need four whirlybirds.

Based on these recommendations, a good rule of thumb may be that you should install one whirlybird per bedroom in your house.

Is a whirlybird right for my home?

Before you decide to install a whirlybird (or several) on your roof, you may want to consider the cost. This will largely come down to the size of your home, as well as how well it’s currently ventilated.

A larger home means a larger cost

If your home is relatively large, with four or more bedrooms, you may end up paying more than $1,000 to have the appropriate number of whirlybirds installed. But by shopping around and obtaining quotes from a number of different contractors, you may be able to find an installer that offers you a great deal.

Is my house whirlybird-friendly?

According to the Roofing Professionals Westside, whirlybirds are best suited to well-ventilated roof cavities that allow for air circulation. If a roof cavity has inadequate ventilation, then a whirlybird may not be an efficient way of removing warm air from your home.

You may decide to have additional ventilation built into your house in order to improve the future efficiency of any whirlybirds that are installed. This would likely increase your total costs significantly. It may be worth considering whether the benefits of having a whirlybird installed outweigh the financial burden of not only the whirlybird itself, but also the remodelling necessary to make them viable for your home.

What are the ways I could pay for my whirlybird(s)?

There are several ways to pay for home improvements, if you don’t want to front the initial costs, including:

• Personal loan
• Credit card
• Making use of a redraw facility to withdraw any extra money you’ve paid into your home loan (if your mortgage offers this feature)

If you need to borrow money to fund the job, be sure to pay close attention to the interest rate you’re charged by the lender, any fees that apply, and whether you will be able to afford the repayments.

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Cover image source: alybaba/Shutterstock.com.