Before you can start setting up walls, you need to put down a floor. We used 3/4 inch
tongue and grove plywood. This provides a nice flooring material which interlocks for
added strength.

Here is the very first wall going up.
Before nailing the plywood down, make sure that you apply a good wood
glue to help keep the plywood in place and to help prevent squeaks if the nails work
themselves loose. Use a spare piece of 2x4 to pound the sheets of plywood into place so
you don't damage the tongue end of the plywood sheet.
After the floor is all down. You need to go around the house with your blue prints and
mark on the floor where each wall is going to go. This helps you lay out all of the walls
and provides a good check of all of your dimensions. Next you can start building the walls.
To save yourself some time, you may want to build all of your corners, t's, headers and jack
studs ahead of time so that once you begin laying out walls, it is just a matter of grabbing
what you need from the right pile. Make sure that you have equipment or enough people to help
lift the walls up as they can be heavy. We went with 2x6 outside walls and some of the large
walls required 5-6 people to lift them up into place.

Here are the next set of walls going up
Once the walls are up, make sure they are level and brace them against the floor and each other
to make sure that they don't come down once they are up. Once you are sure they are in the right
place and you don't have to make any further ajustments, nail the walls to the floor and to each
other. When all of them are up and in place, you need to put a top plate all along the top of the
walls. This consists of either a 2x4 or 2x6 (depending on the thickness of your walls) layed flat
and forming a solid layer all along the top.
The top plates main function is to secure walls together by bridging the joints formed by two walls
coming together. If the joint of a top plate is directly over the joint of a wall, you will defeat
the whole purpose of the top plate and decrease the stability of your house.

Here is the First Floor with all of the walls built
When you have everything nailed together and you are ready to start the second floor, stretch
another string along the outside of each wall to make sure that they do not bow in or out.
Adjust the braces accordingly if need to move the walls in or out. Depending on your layout
of your house, you may have to build the interior walls before you can begin on the second floor.
If you are having an wide open area, then you will probably have to build a beam to support the
second floor. Otherwise, you can use the interior walls to support the second floor. If you do
build the interior walls, remember to top plate them and attach them to the exterior walls. This
is another good time to check your dimensions corner to corner.