Here in Queensland, and Brisbane in particular, it is very common to raise an existing home and build underneath! There are many benefits to house raising renovations/extensions, with the main one being the ability to double the floor area of the home without reducing the amount of yard available to enjoy the benefits of outdoor living we love so much in Queensland! However not every home is suitable for, or justifies the cost of raising! There are a few key questions and points to consider!
Can I raise my house and build underneath in Brisbane?
In Brisbane many homes constructed in the Queenslander or Post War style, these homes are built on stumps elevated off the ground, and have timber frames with cladding (typically weatherboard), this makes them suitable for raising. To state the obvious, full brick homes are not suitable for raising. Many areas in Brisbane City Council region have a Traditional Building Character (TBC) overlay, which references the BCC Character Code and Demolition Code, these codes are designed to maintain the traditional character within these areas and controls both what can be demolished and also what can be built new. There are several exemptions that can apply to Brisbane house raising projects, your designer and/or town planner will advise on whether your project has this overlay and what impact it will have on your project.
Can I move my house when I raise it?
Absolutely, your house can be moved a little or a lot, including rotating it to square it up on the block if necessary. There are different ways this can be achieved, the house raiser will work out the best way to do this for your particular situation. Moving the house obviously adds some cost to the overall raise, however it is not as significant as you might think!
How much does it cost to raise a house in Brisbane?
I’m sure you’ve heard about “how long is a piece of string” questions, well this definitely is one of them! Costs vary depending on a number of factors, namely the size of the house, accessibility and slope of the site, complexity of the existing floor framing, it is commonly said that the cost to raise will be between $20,000 and $50,000. House raising companies are definitely best placed to give you pricing under current market rates, however in our recent experience full raising costs will likely be around double these figures, even before turning soil for the new work.
How high can I raise my house in Brisbane?
The BCC planning scheme states that the maximum height for a home in most low and medium density zones is 9.5m. This is actually measured from what is referred to as Natural Surface Levels, rather than the current site levels. This is effectively council’s records of the slope of the site prior to any construction, earth works, etc. The measurement is taken at the point of greatest difference, so this means that all parts of the building must be less than 9.5m from the “natural” ground directly below. It can be possible to exceed this height, especially in areas with flooding, however this will trigger assessment by council via a Development Application.
Is it better to excavate or raise?
This is very much a project by project scenario, it will be dependent on the slope of your site, your brief and your budget. Excavating can work very well if you are building under only a portion of your building and you are not needing to restump the entire house, however as a direct comparison the cost for a whole house situation, can be very similar, in which case typically the raise will give a better end result. When excavating you always need to consider retaining and water proofing scenarios, which can add a bit of complexity at times. Some projects may end up being a little of each, finding the balancing point on a sloping site is critical to coming up with a design that works best with the site.
Considering all the above, the key question becomes whether it is economically viable to raise your home or is there another option that will give you a better result for your budget! Based on the cost involved, for many homes without the TBC overlay’s demolition restrictions, it can actually be more cost effective, and a better end result to demolish the existing house and build a new home, this is obviously not the case in all instances and is very dependent on the site, the design brief and you desired building type and scale. If you budget does not stretch to the cost of a raise and build in under renovation, there are other options that can be explored to give you the additional space you require, your building designer will discuss these options with you.