The floorplan, The Book, and Algebra 1

Round one of this project was a bust.  I approached it in a freestyle, rough estimate, kind of way and that does not work.  I found this book to show me where I made my mistakes:

This book is short, sweet, and inexpensive.  It's $6.95 on Amazon but free for me because I happen to work for the company that publishes it.  I tried to work in an angle of building this during the week as a "getting to know our product"  project but my manager didn't bite.  One of my major mistakes in the first round was not taking into account the depth of the plywood (1/2') for all the internal measurements.  If you want a structure to be 40" high but it's sitting on top of a 1/2" piece of plywood and it has 1/2" thick piece of plywood for a roof then you need to make the wall 39" to allow for the expansion.  I know, it seems obvious, but I missed that on the first go-round.  So, with that in mind I drew up new plans:

 I am taking a cue from my Lego construction sets and building this in a modular format.  There will be two "modules" that will sit next to each other to form the whole attic.  I will make small overlapping adjustments to the floorboards to hide the seam.  The benefits to this are many, including:

1) it's easier to move it if you need to

2) it's more forgiving of mistakes

3) it will be more structurally sound

4) I can add more modules to it at a later date if I want to expand it

I did not include the roof pieces in this drawing because I really want to get the wall and floor shells together first so I can get accurate measurements for what I need for the roof.

So, according to this plan I need the following pieces of plywood:

(2) 33" x 24"

(2) 32 1/2" x 17 1/2"

(2) 40" x 23 1/2"

for that last one, don't forget that Lowe's doesn't make diagonal cuts for you so I need to give them the largest dimension of the piece.  The two side walls will be 40" high and slope down to 17 1/2 inches high.  Well, it is an attic ya know!  Now I have to go look at all the various pieces of wood that I already have and see what I can salvage.

Before I do that though let's have a quick refresher in Algebra 1.  This is how I figure out scale for everything.  According to Google, the average height for a woman is 5'5", or, 65".  Evangeline is 18"So...

For the highest point, 65"/ 18" = x"/40", now you cross multiply and divide and you get 144".  On the shorter end, you have 65"/18" = x"/17.5", cross multiply, divide and you get 64".  For width of the entire project I have 65"/18" = x"/66", blah blah, you get 238".  Divide all those totals by 12 to figure out feet and what you get is that this project, if Evangeline were human, would represent a 20 foot long section of attic that has a gable of 12 feet and a slope to 5 1/2 feet.  not bad!