
Our method for calculating your homes exterior
square footage and generating estimates is: very fast, backed
by 50+ years of experience, uses modern technology, is accurate
down to the square inch & generates extremely detailed information
about your homes exterior. Although we at Exciting Home
Exteriors exclusively own and use this system you can calculate
your homes exterior square footage in the same detailed fashion
as our system does. Here's how:
HowTo calculate your Homes Exterior
Square Footage down to the Square Inch like Exciting Home Exteriors'
does.
 Use the detailed method explained
above to get your homes "overall raw" exterior square
footage with one difference  your measurements should be down
to the fraction of an inch. (i.e. 234 1/4 inches would be 234.25
inches)
 Deduct anything that does not get siding. (i.e. windows,
doors, chimneys, brick work and the like.) Remember to keep
your measurements down to the fraction of an inch.
 You now have your homes "raw" exterior square footage.
This measurement is your homes exact exterior surface area down
to the square inch.
 Now you must calculate material
waste. This is where experience comes into play.
Different siding products have different waste percentages in
relation to your homes exterior and that relation can and does
vary from house to house. But, that variation usually
fluctuates from 10% to 15% (usually). So a good number
to use (again we are getting back to ballpark estimates) is
12.5%. Example: if your raw exterior square footage is
1,500 square feet times 12.5% (.125) equals 187.5 square feet.
Now add that to your raw exterior square footage and you get
1,687.5 square feet. Or you can skip a step and multiply
your raw measurement by 112.5% (1,500 x 1.125 = 1,687.5).
This is a time consuming process to do long hand but it is very
accurate.
Material
Waste: A Closer Look
The factors involved in calculating material waste include: product
coverage area, wall dimensions and applicator expertise.
Product Coverage Area:
Let's look at an arbitrary siding panel. It's dimensions
are 11.5 inches tall by 144 inches long. We are going to
use a 1.5 inch overlap so, now the coverage area of the panel
is now 10 inches. To get the coverage area of the individual
siding panel (uncut) is 10 inches times 144 inches which equals
1,440 square inches. But we need square feet so we must
convert the square inches to square feet. To accomplish
this we simply find a common ground between the two. Let's
take a single square foot (1 foot x 1 foot = 1 square foot) also
there are 12 inches to one foot so we will substitute feet for
inches to get our common ground ( 12 inches x 12 inches = 144
square inches.) So our common ground is 1 square foot (1sq')
equals 144 square inches (144sq"). Looking back at
our arbitrary siding panel, 1,440 ÷ 144 = 10sq'. Now you
know how to calculate a panels coverage area.
Some products will generate
more unusable waste than others. For example, if a wall
is 101.5 inches tall and a siding products coverage area height
is 10 inches, 101.5 ÷ 10 = 10.15, so that's 10.15
panels high but only .15 or 1 1/2 inches of the last panel is
used. So that's 8 1/2 inches wasted on the last panel, or
85% of the siding panel wasted, if you only accounted for 12.5%
overall you will come up short on your siding product and have
to pay for more. For some products, if there are an adequate
amount of small areas or usable areas on a home a lot of the waste
can be used in those areas. Again this is something you
only really learn from experience.
Wall Dimensions: Sometimes
the products selected just don't match the walls to be covered
and a lot of waste is generated. If you don't have a plan
on how to utilize your waste ahead of time you could get stuck
with a lot of cutup product which cannot be returned for credit.
Ok, so your thinking I'll just get a whole lot of product and
return what I don't use. If you do this make sure you understand
if you can return the product to the supplier and if they charge
a restocking fee (most do and it's around $10 to $20 per $100
lost to a restocking fee.) Also, having too much extra product
on a job site tends to get damaged.
Applicator Expertise:
As you can imagine, if the applicator doesn't know what he/she
is doing he/she will waste a lot of material by miss cutting it.
Also, a skilled applicator will utilize waste by installing siding
on the waste generating walls first, then using that waste on
other walls. Our applicators and our owners (who are applicators
themselves) have done entire siding jobs and produced such minimal
waste that it fit into a single garbage can. This amount
of waste generation is rare but, for a skilled applicator who
uses their head and keeps waste in mind, product efficiency is
a natural outcome.
Few things frustrate a siding applicator more than a shortage
of materials on a job site. Also, not accounting for material
waste appropriately can really increase the material costs on
a job. We wish you the best on your project! 