Why Does it Cost so much more to Build a Second Storey Home?

Building a second storey on an existing home or building a completely new one with two storeys is always a dream for many homeowners. For whatever reason, they either want more space in their backyard and therefore prefer to go up, or they have fantastic views they would love to capture by going up another level in their home.
 
Whatever the reason, it better be a good one, as the cost to build a second storey is always more per square meter when comparing the price of a single levelled home.
 
Now, we do not like to talk square meter prices here at Distinct; however, in this case, there is no other way of explaining this concept.
 
There are several reasons why building a two Storey home is more expensive, I hope I can shed some light on these reasons in this post now.
 
In no particular order, let me explain to you from a builder's point of view, what costs us more money and why we have to charge you as the homeowner for those added costs on your two storey home extension or two storey new build.
 

Scaffold
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This one is an obvious cost that most people forget about! 

When building a single level home, you very rarely need scaffold and if you do, it is usually for a shorter period of time and much cheaper.

Therefore, this is quite a large cost to add on to a job that you essentially get no return or real value from. It is purely there to make it possible and safe to build your home.

Scaffold bills normally start from around $14,000 for 12 weeks hire on a standard top story home extension and can go into the hundreds of thousands on bigger and more complex larger two story or three story new built homes.

There is no way it is possible in Australia to build a two-story home without the costs of scaffold. Health and safety would not allow and if your builder agrees to it- Buyer beware! 

One other thing to be mindful of is that, if the home must be painted once the top level is all complete or rendered, then the scaffold hire period must be longer and therefore costs more.
 

Structural Materials Expense
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As you are building on top of a floor below, there will be a requirement for extra structural support.  The steels or larger timber beams to support the second floor will always add a more significant chunk to your structural steel or timber materials bill.
 
Large LVLs and Steel columns and beams can cost around $10,000 a build, depending on the specifications from the engineer. This does not include all the other materials required for the frame, whether brick, timber stud, or other selected material.

Just the structural materials bill alone is significantly more than a single-story home.

Also, this can create the need for a crane hire or more extended crane hire to install those structural materials. Also, more men are needed to install, which can increase the trade component cost. 
 
Further, if you have selected to use concrete as your preferred second-story flooring, the suspended slab will add even more to your structural materials bill required for this build. This leads to the next reason why a two-story home can cost more than a single-story home: time. Building a suspected slab over a timber subfloor or Hebel flooring system can add significant time. Your home may sit there for 4-6 weeks with no trade on site.

Time
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To build a second-story home, be prepared for a longer build time. Coordinating all the trades and ensuring the build runs smoothly is a much harder job on a second-story home; many more variables must be considered when managing a two-story house project.

The timing it takes to build a 300m2 single-level home vs a 300m2 two-story home could be a 6-a 12-month difference or more in some cases.

Each trade will likely have to come on-site at two separate stages of the job u, usually first floor and ground floor stages. Timing all trades on the job is also much harder, especially in a booming market as we are experiencing now when tradies are so busy. You may find that your tiler is returning to tile the splashbacks but needs the plumber to fit off a sink or tap. However, that plumber is held up on a job and can’t get there until next week. These two weeks held up x 2 can be horrible but uncontrollable for builders and trades.

This is a similar problem on single-level jobs but times this by two, as you have two stories and get a much more extended wait period. The trades will generally finish off the top floor and then work on the ground floor once that is watertight and locked up.
 
Now, as we all know, time is money, so it is also for the builder. Builders like to get your job done as quickly as possible; otherwise, it costs them more in overhead costs, which is always reflected in the homeowner's prices no matter how much a builder will try to disguise this! No builder I have ever met likes delays or hold-ups on site.
 
Due to things taking longer, this increases the cost of hire items such as toilet hire, tarp hire and other items that are hired daily or weekly.
 

Stairs
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Now this one is super obvious!

However, it is an actual cost that is not needed on a single-level homes.

You need to safely get up and down from the first level, and the only way to do that is via a lift that is very expensive, around $60,000+ or of course stairs! 

Stairs can cost anyway between $8,000 for basic MDF stairs and carpet and go as high as $100,000+ depending on your final specification. I am sure you have all seen some amazing free flowing stairs made for custom steel and large solid timber treads, while they look great, they do cost quite a bit. A cheaper alternative is to do MDF stairs with timber treads and risers and create a study nook underneath, this way it still looks nice and also becomes a functional space underneath. We then also like to make a storage cupboard with the extra space under the stairs and alongside the "nook" 

Conclusion

The above are the obvious costs to a builder that must be factored into every two-story extension or two-story new build that we build.

I usually advise most homeowners that enquire and ask the question; you need an extra $40,000 minimum to go to a second story if comparing the same like-for-like cost home on a single level.  This can range depending on the design, which is why you need to work with your builder from the get-go when it comes to designing your dream home or next property project.
 
If you would like to discuss your potential project, please feel to reach out to Distinct, and we will be happy to answer your questions.
 
If you fill out your contact details, you can use fill in our survey, which will be emailed to you so we can better understand your project before reaching out.

Thanks for taking the time to read this and I hope you got something out of it! If so, please feel free to forward to a friend or family who may also benefit from this advice.