How to measure a house.

So you have decided that you are tired of looking at that old exterior finish.  Maybe, it is time to repaint again. (Didn’t you just re-paint a couple of years ago?)  Or maybe, you just need to drag your house, kicking and screaming,  into the twenty first century.

Vinyl siding and Hardi Board come in a wide selection of colors and styles, giving you and unlimited range of combinations to choose from.

Before you start your siding project, or before hiring a professional siding company like Viklund Contracting, it is helpful to know how much material you are going to need  in order to estimate the job’s cost. This initial information not only helps you budget for your project, but gives you the estimated materials needed to complete the job.  If you have decided to hire someone to install the siding, you will know from these initial measurements if you and your installer are on the same page.

Step 1: Take Measurements

You will need: a pencil, paper, measuring tape and ladder. The goal is to measure and record the heights and width of each wall to be sided, exactly the same as you would do if you were going to paint a wall.

1. Sketch each wall

It doesn’t have to be a Van Gogh drawing, just something simple to keep track of the measurements as you go around your house.  All houses can be broken down into shapes of rectangles or triangles, or a combination of both.

2.  Measure each wall

The area to be sided can be determined by measuring the height (bottom to top) and width (side to side) of each wall. Start by choosing one side of the house to be sided, being sure to jot down the measurements on your rough sketch as you go. (you will never remember what they were by the time you do all the walls)

Windows and door are not usually taken off. Including them provides a buffer for waste when cutting to length.  However, if the windows and doors are extremely large, such as a sliding glass door or say a picture window, feel free to deduct these from your measurements.

3. Oh my gosh…How do I measure a Gable?

You are walking around your house, diligently taking notes on height and width, when you realize you have a couple of gables thrown in for good measure. Don’t panic… simply measure the base length of the gables triangle and the distance from the bottom of the triangle to the peak (height). Write these numbers on your sketch.

Now let’s put it all together.

4. Finding the area of a wall

To find the area of all your rectangular walls, simply multiply their length by the height.  The result is the area of the rectangle wall.  Jot it down on your Sketch.

Length _________ in feet X Width (height) ________in  feet =  Area of  Wall


5. Finding the area of the gable.

The gables may appear tricky to calculate,  but the same principle applies.  Start by multiplying  the base length of the triangle by the height (distance to the peak).  Then divide the whole thing by 2.  Jot down this number on your Sketch.

Length  ______ in feet   x   Width (height from bottom to peak) _________in feet
___________________________________________      = Area of Gable             



6. Adding it all up.

Calculate the area of all the rectangular walls you measured, and calculate the area of all the gables you measured.  Add all these numbers together to get your Total area.

7. Add another 10%

It is important to add 10% for wastage when cutting siding and trims to length.  This also helps buffer you from  any unseen material damage or breakage due to shipping.  It is always better to order too much siding than to come up short and have to run back to the supplier.   Most suppliers have a return policy for unused vinyl material.

However … please note: Suppliers will NOT take back any Hardi board material.  Due to the fact that they can’t be certain it was stored correctly while being installed on your house.  It is critical that the back of the cement board material stays dry as this part of the board is not covered by paint. Even if you are diligent, the supplier will not let your return any Hardi board or trims they shipped to your house.

8. Measuring for trims; starter strip, window & door trims, soffit- J etc.

I know, you thought you were done at this point. But you are almost there… Next:

  • To estimate the amount of starter strip required measure the linear feet around the entire base (perimeter) of the house.
  • Measure the distance in feet around all sides of doors, windows, exhaust vents, outdoor plug-ins, box outs, power meters etc.
  • Calculate the distance of all gable lengths, near the soffit line.
  • Now, measure the height of all inside corners. Make sure to measure any feature on your house that creates a corner, such as inset door or bumped out windows
  • Adding together all the measurement for B & C & D will give you the amount of vinyl-J trim required for your project.  REMEMBER to add 10% to this total as well.  If you are not replacing your soffits, be sure to add in J-trim that will bump up against the soffit line to finish the siding.
  • Measure the top of all windows, and doors (include batons), belly bands and decks or stairs that touch the side of your house, to calculate the amount of Drip Cap you will require.
  • Measure the bottom of all windows & belly bands to calculate the amount of Reverse Drip Cap
  • Count and measure all your Outside corners. You will need to purchase Corner trims for each outside corners. (Most vinyl corners come in 10 Foot lengths. So if you measure 11.5 feet to the top of your soffit line.  You will need to purchase 2 corner trims to cover this corner.)
  • If you are replacing your soffits you will need to calculate the distance in feet all around the top Perimeter of your house. (At the soffit line.) Don’t forget to add in gable soffit lines as well. This will give you the number of Aluminum-J’s you will need to install new soffits. Remember to multiply this length by 10% for wastage.
  • Measure how wide each roof overhang is and multiply that by the distant of each section. That will give you the amount of Soffit you need to purchase.

9. Pricing your Project

Depending on your budget it is alway wise to choose a couple different siding choices with differing price points. The cost of the vinyl siding itself will be determined by the style, color, quality, thickness and whether or not it is insulated. The cost of Hardi siding will be determined by revel style, number of batons and whether or not you choose to install additional insulation under the new cement board.

In addition, all siding project involves assorted trims, corners and channels for soffits, etc. Contact your local retailer or consult with your contractor for help with pricing.

To get a general idea of the material costs of your siding project, take all of your measurements for each item separately, then multiply the running or square footage of by the dollar amount per foot or square foot of each item.

For example:

Wall area in square feet x price of vinyl per square foot = cost per square foot

Vinyl-J or Alum-J in feet  x price of per foot = cost per linear foot


And if all else fails, and you feel overwhelmed by the whole process.  Call us today!

We would be happy to measure and price your siding job for you. Big or Small we are the right team to call.

Don’t forget you may need new Gutters to finish off your beautiful new siding project!

Keep your Home out of the Gutter … Call us today for a Free Quote!

For all your exterior siding, vinyl siding and hardie siding projects. Serving Didsbury, Sundre, Olds, Carstairs, Cremona, Watervalley, Cochrane, and Airdrie.
10-31342 Rge Rd 43A
P.O. Box: Box 5 Site 2 RR1
T0M 0W0