For this building a home guide project we will be building a small, energy efficient economy home. This article will help you visualize the process. The same principles apply to larger homes, and this little home does pack a punch in economy and efficiency.
The home will be a 20 by 24 gambrel roof home with wrap around loft 12 by 16 foot on one end of the home, and a narrow loft extension on one side. I recommend this area for an upstairs and downstairs bath or a walk in closet upstairs if you prefer. We will be framing this home the old fashioned way, with two by six wall studs. The inner dimensions of the home are therefore, 19 by 23, for 437 square feet on the first floor, and an additional 192 + 48 square feet on the loft. An additional 172 square feet can be added later by building and closing in a shed roof back porch area. Even more space, up to another 132 square feet, could be created by closing in part of the front porch, with perhaps a sun room. Therefore our home can grow from 677 square feet, to 933 square feet. It would also be possible to build onto the eve ends of the home if you desired, for space limited only by the size of your lot. Our floor plan is loose and versatile, with plenty of room for expansion.
We will call the 24 foot exterior walls front and back, and the two 20 inch walls entry and side to avoid confusion.
The first step will be to clear and grade the lot level in the tiny spot which will be covered by the home. If the lot is flat, very little grading will be necessary. Then we will have a concrete contractor dig and pour a 20 by 24 footing and build the foundation, but if you desire you can have an 8 foot porch foundation created, which will extend out 8 feet on the front and back sides of the home, making a total foundation area of 36 by 24. You could however wait till later to build on the porch foundation and the porch. This is the beauty of our simple add on plan.
You will want to hire a plumber and electrician to do the rough plumbing, and wiring under the home. They should be able to complete the job in a day or two. This part of the plumbing is not difficult, and you may choose to do the rough plumbing yourself with PEX pipe if your building code and inspector will allow it.
Once your foundation is complete build a sill plate and a system of floor joists to cover the foundation. Cover this with three quarter inch OSB plywood, being careful to countersink your screws, and cover with wood putty. Use a carpenter’s level and a square frequently throughout this stage to insure that your floor joists are level. It’s a lot like building a deck, except you will be covering it with plywood.
Next you will be framing your home with two by six inch studs. You will be building the frame for the wall in eight foot sections on the subfloor and then raising the wall and nailing or screwing it to the subfloor in it’s proper location. Remember to frame for doors and windows. I would recommend a central door on each side of the home, except for the entry one because that is the stairway side. That door must be nearer the front. You could use glass patio doors for any of the doors you choose, except for the front door, and the door on the north side of the home. Place the windows where they are visually appealing and balanced with the same size and spacing on either side of the doors.
When you have framed the exterior walls, create an interior wall, six feet from the exterior wall along the back side of the house for about 12 feet six inches. The stairway will be placed along this wall, so you will build a small platform landing three feet by three feet and 32 inches high, in the corner created along the new interior wall where it intersects with the entry wall. On the back side of your wall you can build a 6 by 12 foot bathroom. Go ahead and finish off framing the bath by creating a six foot wall connecting the interior wall and the back wall. You may either place the door on this end or create an under the stairway door on the tall end of the stairs. If you elect for an under the stairway door, it will have to be smaller than standard, and you will probably have to custom make it, or adapt a salvaged door.
Now place a six by eight inch post so that it is 3 feet away from the interior wall towards the front and at the twelve foot mark. At this point it should be a little over ten feet from the front wall, and 12 feet from the entry wall.
Once you have finished the wall framing, move up to the upper sill and ceiling joists, which will cover only half of the area completely. You will use 2 by 10 lumber, short side down and nailed to the top of the frame walls. Start by building sills around the parameter of the house and over the interior wall you build. Then connect the interior wall to the back wall, with a 2 by 10 cut to six foot long. Next you will join the interior wall on the other side across half of the post, with a three and a half foot long 2 by 10, and nail it in place. Finally take a 12 foot 2 by 10 and cut it to fit the expanse between the upright post and the front wall at the 12 foot mark. Now you can frame in your ceiling joist system, and cover it with plywood, just as you did the lower subfloor.
You can now build a stairway to connect your loft to your three by three foot landing platform, and from your landing to the floor. It should be three steps to the landing, and the rest going up to the top floor. Steps should be no more than 8 inches tall and at least 10 inches wide. You may buy precut stringers or cut your own. There are calculators on line to help you with the math if you cut your own. Attach the stringers to the loft and the post on one side and the wall on the other. This should give it added stability. Saw off the post at the proper height to be a banister post.
Framing a gambrel roof can be fun. Draw a line on the floor or mark a point two feet from the edge. This marks the edge of your interior wall. To create the framing simply create a series of right triangles from wooden studs, so that the inner upright board is at a 45 degree angle with the board on the floor. Your outer board will have a very short angle at the bottom and a sharp angle at the top. This board will form the outside angle of the roof which will be very steep. The length of the other boards is not crucial, but you will want this board to be 8 foot for easy sheathing. Your ceiling height will be about seven feet for the loft.
You will want to create another frame around the top of this, but rather than use the joist plan on top, with two by tens, simply join the triangles together at the top on the interior side with two by six lumber, and frame it in with lighter weight joists. two by six stud lumber should be sufficient. There is no point in using OSB. Instead go directly over this with standard 3 over 12 inch rise, 16 foot trusses. You have an option of either wooden or metal trusses for this project.
Next you will sheath and roof the trusses, and the 8 foot gambrel sides. Using roofing instead of siding on the upper floor, not only looks cool. It saves money, because roofing shingles cost less than siding. You might also consider a tin roof for a really beautiful rustic effect. I recommend a tin roof covered over with solar panels on the top over the trusses. This won’t show much because of the low rise and will allow a maximum sun exposure for the panels.
Now that your home is framed and under roof, you can sheet the exterior with OSB plywood and install windows and doors. You now have a shell on a foundation, so relax and finish the interior of your home as you desire. You will still need the electrician, and perhaps the plumber to assist you with plumbing and electrical. You will also need to hire a closed cell insulation contractor to blow in the closed cell insulation to fill the walls and the short attic. When using this building home guide as a basic idea, for a simple home, you should have no trouble understanding how the home works. Finish your home in whatever way you desire.