Before coming in like a wrecking ball, estimate the debris first
The equation for demolition calculation is: length of space (in feet) x width x height x 1/3 ÷ 27 = demolition debris in cubic yards.
Expect to spend an average of $800 on a kitchen or bathroom demo and $15,800 on a whole-home demo, depending on the project’s specifications.
Hiring a demolition contractor can save you a lot of time in complex calculations and labor for large and dangerous demo jobs.
You’re finally tearing out that outdated kitchen and laying the groundwork for fresh granite counters, sleek cabinets, and beautifully tiled floors. But before you can build the kitchen of your dreams, you need to make space for something new. One important step of demolition is estimating the amount of debris you’ll produce so that you can rent the right-sized dumpster to hold it all. Learn how to calculate demolition in a few simple steps.
You (or the demolition pros you’ve hired) will need to calculate the anticipated waste from your demolition project in order to rent the proper number of dumpsters to haul away the demolition debris. You’ll need to haul the demolition waste away as soon as possible to finish the demolition and move forward with your home improvement project.
When learning how to calculate demolition waste, you’ll need to calculate for cubic yards. But you’ll also want to account for any airspace, or the empty spaces between walls, floors, and other materials that won’t turn into debris that needs to be hauled away.
That’s why it’s important to follow the 1/3 rule to account for this extra space. To calculate demolition waste, you’ll need to multiply the area of the space, measured in cubic feet, by ⅓ before dividing that total by 27 to get an accurate estimate of debris in cubic yards.
Here’s a basic equation to follow to estimate demolition debris:
Length of space (in feet) x width x height x 1/3 ÷ 27 = demolition debris in cubic yards
You may be wondering why you need to convert the total cubic feet into cubic yards. As it turns out, many dumpster rental companies measure the dumpster size by cubic yards to help succinctly measure the debris volume.
While dumpster rentals are measured by their cubic yard capacity, they also have weight limits. You’ll need to let the company know what waste materials you’ll be throwing out since materials like concrete and brick are heavier than materials like drywall and roof shingles. A small dumpster may have a weight limit of around 1,000 pounds, while bigger dumpsters may hold up to six tons of waste.
Let’s break down each part of the demolition waste calculation, starting with finding the area in square feet to calculating for airspace to converting the estimate into cubic yards.
Start by calculating the area of the space you plan to demolish. You can either check the blueprints of the house or grab a measuring tape and measure the length, width, and depth of the space. Jot down each measurement in feet and multiply the three measurements to determine the area in cubic feet.
Length (feet) x width (feet) x height (feet) = Area (cubic feet)
The room or area you’re planning to demolish isn’t just one solid block of materials. There are spaces in the room as well as spaces between drywall. To estimate a total without including airspace, you’ll need to multiply the area in cubic feet by 1/3.
Area (cubic feet) x 1/3 = Area (cubic feet) after accounting for airspace that will not become debris
If you need to rent a dumpster or truck to haul away the demolition debris, you’ll want to know how many cubic yards, not feet, of waste you expect to have. This will make it easier to calculate how much dumpster space you need, since cubic yards are the standard measurement for dumpster capacity.
Area (cubic feet) after accounting for airspace ÷ 27 = demolition debris (cubic yards)
Once you have an estimate of the cubic yards of waste that the demolition will produce, it’s time to calculate how many dumpsters you’ll need. Dumpsters come in standard sizes of 5, 10, 20, 30, and 40 cubic yards.
Demolition debris estimate (cubic yards) ÷ dumpster capacity in cubic yards = number of dumpsters (round up if you get a decimal)
For example, if you estimate 100 cubic yards of waste from a demolition, and you want to rent 20-cubic-yard dumpsters, you’d need five dumpsters.
The cost to rent a dumpster for demolition debris is $200 to $800 per week on average, and the cost to haul away junk is $60 to $700, depending on the amount of waste.
Demolition costs can vary widely based on the project. On average, you can expect to spend $4 to $20 per square foot, but here are some common costs based on the type of demolition.
Entire home demolition cost: $6,000–$25,500
Garage demolition cost: $2,000–$10,000
Kitchen demolition cost: $300–$3,000
Bathroom demolition cost: $300–$3,500
Concrete demolition cost: $600–$1,800
Pool demolition cost: $5,000–$8,000
Hiring a local demolition pro can help you get the most accurate demolition and dumpster rental cost estimates. Plus, the pros will make sure to pull the proper permits and demolish the site safely and efficiently so that you can get on to the more exciting part—starting your next home improvement project.
Demolition costs $4 to $20 per square foot, with the total depending on the size and complexity of the demolition. Tearing down an old shed or garage with no plumbing or electrical to worry about is a quicker, less costly job, but demolishing a bathroom or an entire home is a bigger project that requires more workers and heavy-duty equipment that drive up the cost.
Demolition includes wrecking, razing, or otherwise destroying an area or property, and with professional demo contractors, the process also includes surveying, permits, and debris removal in the cost. Pros will help prepare the site with inspections and surveys, demolish the area, haul away the debris, and clean up the area.
There are several tasks to check off to prep for a demolition, including scheduling an inspection of the site, obtaining building permits, scheduling utility disconnections, and calculating debris removal to rent the proper amount of dumpsters. It’s also helpful to let neighbors know about the upcoming demolition work. It’s best to consult with demolition specialists before starting a demo project to make sure you’re meeting local regulations for this type of work.
