Step 1: Measure Your Exterior Walls

Width: Measure the total length of all exterior walls

Height: Measure from the bottom corner trim to the roofline

Step 2: Measure the Gables

Width: Measure the length of the gable (green arrows for guidance).

Height: Measure or estimate the distance from the base of the gable to the peak.

Disclaimer: No need to climb a ladder; measure what you can from the ground, and give an estimate.

Step 3: Count the Windows and Doors

Windows: Enter the number of windows

Doors: Enter the total number of swing doors (exclude sliding glass doors or garage doors).

If you’ve made it this far, you’re clearly serious about protecting your home — and we love that.
This JamesHardie siding calculator is a great tool for getting a rough idea of how much siding you might need, but every home is different. From unusual angles to hidden dry rot, there’s a lot the calculator can’t see.

That’s where we come in.

At SFW Construction, we’re experts in siding repair and replacement — especially when it comes to JamesHardie siding products. We’ve been doing this for over 20 years, and we’ve seen (and repaired) it all: weather damage, water intrusion, construction defects, dry rot, and more.

So whether you’re just comparing costs or ready to schedule an inspection, our team is here to help you move forward with confidence.

Think of this JamesHardie siding calculator as the first step in the process — we’ll help you with the rest.

We’ve helped thousands of homeowners — you’re in good hands.