James Hardie, commonly known as Hardie Plank, is a brand of fiber cement siding that has become incredibly popular among homeowners and builders due to its durability, resistance to fire, pests, and weather, and its aesthetic versatility. Unlike traditional vinyl siding, Hardie Plank offers a more premium look and feel, often mimicking the appearance of wood. However, this premium quality comes with a higher upfront cost. This calculator aims to provide an estimated cost for installing Hardie Plank siding on your home.
How the Calculation Works
The total cost of installing Hardie Plank siding is determined by several factors, including the materials, labor, and waste. Our calculator breaks down the estimation process as follows:
Calculating Total Siding Area:
The primary area to be covered is the wall surface. This is calculated by multiplying the house width by the house height. We then add any additional areas like gables.
Wall Area = House Width * House Height Total Surface Area = Wall Area + Gable Area
Accounting for Openings:
Doors and windows do not require siding. Therefore, their area is subtracted from the total surface area to get the net area that needs siding.
Net Siding Area = Total Surface Area - Door & Window Area
Adding for Waste:
During installation, cuts are made to fit siding around corners, windows, and doors, leading to material waste. A waste factor, typically between 5% and 15%, is added to the net siding area to ensure enough material is purchased.
Billable Siding Area = Net Siding Area * (1 + Waste Factor / 100)
Calculating Material Cost:
This is the cost of the Hardie Plank material itself, based on the price per square foot.
Material Cost = Billable Siding Area * Hardie Plank Cost per Sq Ft
Calculating Installation Labor Cost:
This is the cost of labor for installing the siding, also based on a price per square foot.
Installation Cost = Billable Siding Area * Installation Cost per Sq Ft
Total Estimated Cost:
The sum of the material and installation costs gives the total estimated project cost.
Total Estimated Cost = Material Cost + Installation Cost
Factors Influencing Cost
Product Line: James Hardie offers various product lines (e.g., Select Cedarmill, Lap Siding, Shingle Siding) with different textures and appearances, affecting the cost per square foot.
Architectural Complexity: Homes with many corners, dormers, intricate trim, or multiple stories can increase labor costs due to the complexity of installation.
Geographic Location: Labor rates and material availability can vary significantly by region, impacting the overall price.
Existing Conditions: If old siding needs to be removed and disposed of, or if repairs to the underlying sheathing are required, this will add to the total cost.
Additional Materials: Costs for trim, house wrap, fasteners, caulking, and paint (if not pre-finished) are not explicitly included in this basic calculator but are essential project components.
Disclaimer: This calculator provides an estimate based on the inputs provided. Actual costs may vary. It is always recommended to obtain detailed quotes from multiple qualified siding contractors for an accurate project assessment.
function calculateSidingCost() {
var houseWidth = parseFloat(document.getElementById("houseWidth").value);
var houseHeight = parseFloat(document.getElementById("houseHeight").value);
var gableArea = parseFloat(document.getElementById("gableArea").value);
var doorWindowArea = parseFloat(document.getElementById("doorWindowArea").value);
var hardiePlankCostPerSqFt = parseFloat(document.getElementById("hardiePlankCostPerSqFt").value);
var installationCostPerSqFt = parseFloat(document.getElementById("installationCostPerSqFt").value);
var wasteFactor = parseFloat(document.getElementById("wasteFactor").value);
var resultElement = document.getElementById("result-value");
if (isNaN(houseWidth) || isNaN(houseHeight) || isNaN(gableArea) || isNaN(doorWindowArea) ||
isNaN(hardiePlankCostPerSqFt) || isNaN(installationCostPerSqFt) || isNaN(wasteFactor) ||
houseWidth <= 0 || houseHeight <= 0 || gableArea < 0 || doorWindowArea < 0 ||
hardiePlankCostPerSqFt < 0 || installationCostPerSqFt < 0 || wasteFactor < 0) {
resultElement.innerText = "Please enter valid positive numbers for all fields.";
resultElement.style.color = "#dc3545"; // Red for error
return;
}
var wallArea = houseWidth * houseHeight;
var totalSurfaceArea = wallArea + gableArea;
var netSidingArea = totalSurfaceArea – doorWindowArea;
if (netSidingArea < 0) {
netSidingArea = 0; // Cannot have negative area
}
var billableSidingArea = netSidingArea * (1 + wasteFactor / 100);
var materialCost = billableSidingArea * hardiePlankCostPerSqFt;
var laborCost = billableSidingArea * installationCostPerSqFt;
var totalEstimatedCost = materialCost + laborCost;
resultElement.innerText = "$" + totalEstimatedCost.toFixed(2);
resultElement.style.color = "#28a745"; // Green for success
}