Surveying bay windows for new double glazing.

Here I show a copy of my own 'Window Man' site survey for for measuring up bays.

Surveying a bay window at first looks complex, when actually it's just logic, all width measurements are taken from inside, and you have to be very accurate (+ or - 1mm) with the sizes taken.

Note: This is NOT meant for the D.I.Y. or handy person.
This is an advanced technique for existing experienced double glazing surveyors.

I do not show a large detailed bay window survey form, just a small example of my own. An experienced surveyor would carry a similar form with him for measuring up all normal types of bays.

Pythagoras' Theorem:

Pythagoras was a pretty clever bloke from donkeys years ago who foresaw that a simple few button presses on an ordinary cheap calculator would one day be all that was be needed to check out a bay window survey before manufacture. He worked out that "on a right angled triangle the square on the hypotenuse is equal to the sum of the squares of the other two sides".

To skip all the confusing stuff below jump to Bay window survey calculator

To learn how to check out your measurements of a bay with a simple plain cheapie calculator whilst still on site:

You know how difficult it can be to measure with secondary, and if the old bay is a bit twisted or symmetry is suspect, then this formula is the one to use, breaking down all parts into separate single right-angle triangles to 'prove' all of your sizes:

A | B _ C \ - Look at the A B and C on the left and think of them as parts of a bay.

Come to that, the C could be the roof length of a lean to conservatory (add overhang + into gutter).

Enter a size for both 'A' and 'B' to produce the size of the angle 'C' (the hypotenuse).

1.     Multiply size 'A' by itself, write the resulting number down, we will call this number X.
2.     Multiply size 'B' by itself, write the resulting number down, we will call this number Y.
3.     Add the numbers X and Y together.
4.     Press the square root button on your calculator (as sort of tick).
5      The number you see is the size of the long side (i.e. width of the window on the angle).

What you have done is multiply both the right angle measurements by themselves, and added these two resulting figures together, taken the square root, and then this gave you the length of the angled part of the triangle (the actual window size itself). Got it?

After you have got the hang of it, you can use the calculator's memory buttons, which is even easier.

To make life even easier for you, break down your bay into triangles and go online and run your sizes through: Bay window survey calculator

If you find it hard to grasp the principle, just bear in mind that if your sizes for the rectangles work out ok as 'squares', and these triangles work out with this method, then your bay should be A1.

Can you explain all that again in plain English please! O.k., try this:

Q.   What's all this pythago, trigo-whatsit and square root stuff when it's at home then?
A.   Well, it is also known as the 3-4-5 rule, and this might explain it easier:

Here we go with two examples of square roots: 5 is the square root of 25 and 9 is the square root of 81, still with me? If not get a calculator out.

This is the 3-4-5 rule:

Multiply 3 x 3 =9
Multiply 4 x 4 =16
Add the 9 to the 16 = 25.
O.k., we know that the square root of 25 is 5 don't we, therefore a right angled triangle with 'A' at a size of 3, 'B' at a size of 4, will prove the size of the angle 'C' (the hypotenuse) is 5. Got it?

That is how you can 'prove' your bay measurements whilst still on site, even without expensive computer software programs the days of drawing out bays on plywood are gone with this method.

If you don't get it then sleep on it, and it should suddenly dawn on you like a bolt out of the blue.