According to the United States Census Bureau, the median size of a single-family house completed in 2019 was 2,301 sq. ft. On the other hand, the average size of US homes is currently at 1,600 square feet. At 2,000 square feet, a family of five members would be comfortable already. This size typically has a living room, a dining room, a kitchen, and can even have a basement.
Still, a lot of US homes still fall below the 1,000 sq. ft. range, especially in states where real estate sells like gold. This is where the idea of adding a second floor becomes an option when you need to add extra space for your growing family without having the need to buy the next vacant lot or move elsewhere.
However, the expensive second-story addition cost always gets in the way of the plan. But is it cheaper to add a second story or build-out? Let’s find out.
Average Cost of Building a Second Floor
How much does it cost to add a second story? Well, first, it depends on how much you are willing to participate in the construction, how much you want to save, or how much you can’t be bothered.
Those who want to do away with contractors or skilled subcontractors should take note that building your second floor will not be an easy task. Beside being difficult, it is also time-consuming. Also, if you are not an expert, this is not advisable. This will be explained towards the end of this article.
Of course, if you decide to build it yourself, it will help bring your cost down. Perhaps a price range of $70 to $150 per square foot would be workable. So, for a house that is 1,500 sq. ft. wide, the range of the overall cost is going to be around $105,000 to $225,000. But as mentioned, this will all depend on how much work you can do yourself.
The typical range for a remodeling contractor would be around $150 to $300 per square foot. It could also go as high as $400 to $600 or more per square foot as well, depending on the complexity of the designs, materials, and the local labor rates in cities and counties.
For example, in Seattle, ballpark quotations for 2nd floor building costs range from $500 to 650 per sq ft. In San Diego, quotes range from $300 to $400 per sq ft.
So basically, the total cost would be around $225,000 to $450,000 for 1,500 sq. ft. of space for a basic job and $600,000 to $900,000 for more complex construction. This would include 2-3 bedrooms and a bathroom plus the stairs.
If you live in San Diego, expect to spend around $450,000 to $600,000. On the other hand, prepare to shell out around $750,000 to $975,000 if you’re from Seattle, where the cost of living is around 49% higher compared to the national average.
The cost of the second-floor addition is said to be 20% more than the price of the building on the ground floor. So, if you keep track of your previous projects, you’ll have a better idea of what to expect in terms of your construction budget. That’s as long as there are not many years in between the two projects.
Considerations Before Starting
If you are planning a second story for your house, it will be more than meets the eye, so to speak. For starters, you will have to find out first if your house’s existing foundation will be able to support the additional weight of the second floor.
There are structural foundation requirements for adding a second story. Everything from the connections right at the main-level walls, leading to the foundation should be able to meet the code requirements. Older homes are the usual victims of seismic risk.
If you don’t have any know-how in this department but want to take the DIY route, brace yourself for a lot of inconveniences and your plate will definitely be full. Worse, you’ll be prone to making construction blunders. These include putting your home at risk of collapsing, not getting a construction permit at all, having to redo everything after inspection, or worse, all of these.
The safest option would be to tap the services of an expert. They will determine if some or all of the foundations will need to be reinforced. For a consultation with a structural engineer, the cost could be anywhere from $200 to $700, depending on the location and the scope of the service.
An architect service can come in handy to help you create drawings and plans. They usually charge a flat rate of around $700 to as high as $10,000 or even higher depending on the size of the house and complexity of the interior design. At times, architects may instead charge around 7.5% to 15% of the overall cost of the project when the scope includes a full range of architectural services.
Another consideration is how you plan to execute the addition. Are you planning to start from scratch by destroying the roof and building the second story? Are you planning to save the roof by lifting it off in its entirety and placing it on top of the newly-built second floor? Or are you thinking about a modular second story addition?
Ripping off your old roof will definitely cost a lot. But if that’s the plan from the get-go to have a fresh roof and new scenery, its fine. However, if you are trying to save on cost, re-using the roof would be one way to achieve it.
You will need to rent equipment to make sure you can lift it off without any damage. But the rental fee would be way cheaper than having to spend on a brand new roof. Renting a crane would cost around $300 per hour if you’re in North Dakota, but you need to rent it out for at least 4 hours. That would cost a total of around $1,200 at the very least.
The list goes on for the cost of adding a second story to a bungalow. If you are hiring a contractor, you only need to make sure to provide the budget. If you are doing it on your own, there’s a lot more to consider beside the procurement of materials and hiring construction laborers.
First is securing a construction or building permit. If you hire a contractor, this will be included in the service contract. Otherwise, you will need to get it yourself, unless you live in areas where building permits are not required, such as in unincorporated places of Delta County in Colorado.
To give you an idea, the permit fee for a 1,500 sq.ft single-family house construction in Seattle would cost you $4,239. It could be cheaper in other areas, and some states don’t even require permits for home improvements. Consider yourself lucky if this is the case.
After all the additions, your property could be re-assessed by the government, which could result in a property tax increase. In most cases, some areas will only re-assess the value of your second story addition and not the entire property.
All other utilities in the house should work for the homeowner. As per an engineer’s calculation, the water heater, and other electrical items like the panel should be able to work depending on the house’s square footage.
Some of the other added costs will have to be the replacement of your HVAC system and other energy-efficient systems. It is very important that as a homeowner you revisit these parts of your home’s systems to ensure that even when you build a second-floor area, everything you need regarding your utilities should be working fine.
You can also expect your monthly utility bills to increase. This is because if you are using a centralized air conditioner or heater for your old bungalow house, it won’t work on your second story. You will need to install additional units that will significantly affect your budget for utilities.
Your insurance premium should also increase with the addition of the second floor. This is also worth considering, unless, you have it all sorted out from the beginning.
How to add a second floor to an existing house? Ideally, the best way to build a two-story house would be a well-thought–out structure using sound engineering and architecture. With this, hiring an expert will always be the safest choice if money is out of the question. It’s always safe to err on the side of caution.
On the other hand, if you have already planned for your second floor from the time you were building your single-floor house, your foundation might already be built in preparation for the extra weight later on. If this is the case, then, this can be the best-case scenario for you as you complete the construction of your dream house.