How to Build a 12x20 Cabin on a Budget





Introduction: How to Build a 12x20 Cabin on a Budget

About: Just a normal guy trying to make it in life .Good paying job but mindless sometimes .I enjoy making things in my garage to keep my mind going .. Its fun making something new but its more fun taking somethi...

Building a cabin yourself is much more economical than buying a prefab storage shed. The cost of materials for this build, including doors and windows, was around $2,200, which was about the same price as the install would have been on one of this large size if I’d purchased it from a hardware store. I know this for a fact because six years ago I bought a 12x16 shed from a well-known company close to where I live and it cost $2,000 for them to build it and drop it off. Today that same building would cost $4,200. With such a big price increase I decided that if I wanted to add a cabin to my property I had to build it myself.

If you decide to do the same, remember to check with your local authorities to make sure you don’t need a permit. It’s not likely that it’s required for a building of this size, but you never know.

If you would like to see the finished inside of the cabin please click here:

If you would like to see the matching modern outhouse please check this out:

Step 1: Floor Illustration

Here is the 12x20 floor plan showing where the 4x4s and the floor joists would be located.

Step 2: Drilling and Planting the Posts

1st picture: shows my ford tractor and my neighbors post hole digger he let me borrow.

2nd picture: shows the posts planted and the bottom 2x10 stringers.

3rd & 4th pictures: show the upper 2x10x12 and the 2x10x16 upper stringers being nailed in at 7 feet 8 inches.

Step 3: Setting the Center Rafter Board

This picture shows the center rafter board. I measured over 6 feet to the center. The roof is going to be a 5/12 pitch roof so the rafter board had to be 30 inches to the top of the board.

Step 4: Making the Angles for the Top and Bottom of the Rafters

1st picture: shows using a quick square. Put the pivot point at the top of the board and turn the square until the 5 on the * COMMON TOP CUT* line graph lines up with the outside of the board. Then draw the line to make the angle.

2nd picture: Once you cut your first angle then you have to measure from the tip of your cut down the length of the rafter to get your measurement for the seat cut. Once you have that measurement then you put the pivot point on that mark and turn the square until you get your 5/12 angle again. Then measure up that angle 2 1/2 inches and draw that line.

3rd picture: shows taking the edge of the square and lining it up with the 2 1/2 in line and turn the square until the tip is lined up with the edge of the board. Then draw that line.

4th picture: shows the angle seat that I just drew cut out.

Step 5: Setting the Rafters

1st picture: shows the rafters being set next.

2nd picture: shows the rafters on and the starting of the purlins being put on the top of the rafters for roof support. This is what the metal roofing is screwed to.

3rd picture: shows the tails all cut to 9 inches long and shows the steel roofing over hanging the roof by 2 inches to support the facia boards.

4th and 5th pictures: show the roofing installed.

Step 6: Adding on a 4 Foot Porch

Here is where it started to get complicated for me. I was looking for a 12x16 cabin, but once i looked at it I decided I wanted the whole 12x16 for floor space so i added a 4 foot porch to the 12x16 to make it a 12x20 total building instead of a 12x12 inside living space.

Step 7: Side Wall and Purlin Illustration

Step 8: Lag Bolting the Outer Joist to the 4x4 Poles

I had to screw (36) 3x3/8 inch lag bolts to all the outer joists into the 4x4s for stability.

Step 9: Hurricane Studs

1st picture: shows the (20) 13 inch hurricane studs with the 5/12 pitch angle cuts.

2nd picture: shows them installed.

Step 10: Floor Joists and Insulation and Floor

1st & 2nd pictures: show the (14) 2x10x12 floor joist installed

3rd & 4th pictures: show the 1x2 furring strips nailed to the inside of the floor joist 1 inch below the top of all the joists.

5th picture: shows the 1 inch insulation board between each joist before gluing and nailing the floor to the joist.

6th picture: shows my Dad lending a hand nailing down the floor.

Step 11: Rough Sawn Lumber for 8 Inch Board and Batten Siding

1st - 3rd pictures: show my dad cutting the siding boards to 8 foot long.

4th - 6th pictures: show the boards up on the wall and the soffit and the facia boards being put on.

Step 12: Studding in the Porch Ceiling

This picture shows the studding in for the porch ceiling, 16 inch centers and 4 foot long studs.

Step 13: Studding in the Front Wall and Door Frame

Studding in the front wall and front door frame, it was a hot day!! Here's my dooraggin' Dad! Just had to take a picture of this! He-he-he...

2nd picture: my friend Josh came over for a day to lend a hand on the mitre saw.

Step 14: Gable Ends

Here are the gable ends finished with the batten strips attached. All that's left for them are the two vents.

Step 15: Finished Cabin Structure

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    Please be positive and constructive.


    6 Questions


    The building code here limits sheds to 10x10 before it needs a permit. What would i need to do to shrink it?

    Ok ,this guy built something rather nice and shared it with all of us, so I get it about building codes, but lets just look at it for what it was intended, a simple share for someone that may want to creat this, again, nice project.

    Do you have a material list?

    I also posted this question , from what I can see ,there is not much of a list but I am planning on doing this soon so I will add one here for my adaptation of this. You basically can start with 4 - 2X12X10 pressure treated lumber and 2 - 2X12X12 pressure treated lumber for the outside box and it appears he used 6- 4"X4"X8' for the uprights.Not much detail ,too bad but for the most part you can make it any size you want which will determine the material list.He wanted the inside to be full size so he used from what it appears 3 4X8 sheets of exterior floor (advantec possibly wax side down).Depending on what you want for floor strength you could set your joist every 12' but he used conventional 16" spacing , if you wanted to use it to store a vehicle or something I would plan on 12" centers for the joist and 1 1/4 marine plywood for the floor.Walls he used strips of wood so he could use something like T111 material and it appears 1X2 pine to have the batten strip appearance. Again I will probably build some rendition of this and post my list if that helps.

    Why are the 1x2 attached below the joists, what is the purpose?

    Where is the "budget" part of this build?

    1 x 2 strips I assume was was to leave a space to put the foam insulation on before the flooring was installed, great idea I would also want to use some 6 mil poly for moisture protection .

    1 more answer

    I think you’re referring to the batten strips. They’re mostly decorative in this case, but we’re used in the old days to hold covering, like tarpaper, in place.

    The “Budget” part of the build is doing it yourself. Back in 2007, when I built a 12x16 two story shed, it cost me about $1200 US (3 windows, 2 doors and vinyl siding). The same one would have cost me $6-8K installed.

    Very nice design, I plan on doing this project and will definitely post pictures , I would greatly appreciate it if you could provide a cut list of materials, I have some to get started but would have a much easier time building this if I knew what I needed first.Thanks for posting , i will also vote on this .

    I'd like to build this in a place where the creeks sometimes rise a couple of feet. Could it be built on taller posts to get the floor above that flood level?

    You probably can, but if it were me, I would:

    A) Pour 10-12” of concrete in each post hole for added stability and to limit settling.

    B) Use pressurized lumber for the posts and floor risers (I can’t see if the author had).

    C) Add 3 or 4 (depending if you’re doing a porch) center posts with a center board under the floor risers, to provide stability.

    The added supplies would add less than $100US to the supply list.


    Was this in US dollars? When you finished, is it just framed or finished inside? Not talking furnished. Thanks.


    No matter what we say. It has been a blessing that he has posted this sequence of pics with descriptions. Not easy. How often do we think of helping others? Not enough. Forgive me if I sounded critical. Well, I did. What can I say? If I had it to do over again I would not have been. Which is ironic because "did I give him a chance to do it over again?" No. Please forgive my being a perfectionist. It is a problem. No one is perfect. We have to love people and edify, encourage and uplift them because ALL of us need it. The content here has been better than any other posts in my opinion. And not because I'm a Reply Hog. I hope I made you think. Never let someone like me stop you because I'm a perfectionist and I am even hard on myself. It's really a curse. So, bless all of you! And I promise to go away now. But I just wanted to say THANK YOU TO THE GUY WHO POSTED THE ORIGINAL INSTRUCT-ABLE. You are a good man to take the time to post this. And it even helped me to work out the fact that I am too critical and I think I didn't know it before. This is valuable. I'm a better husband now even. My wife thanks you :)))

    3 replies

    Yeah! Guess what the reward is for being loving to your wife?

    Seems to be missing a bill of materials or pick list. Has anyone put one together?

    Don't try building this in New Zealand! It does not comply with the Building Code and you also risk a substantial fine if it is constructed without a Building Consent.

    14 replies

    Technically you could build it in NZ if it was less than 10sqm and not connected to the ground (classed as mobile building). However in saying that, it looks like it would not last well due to the way its built (see reasons below in NZ building code).

    Better to keep the wood well away from the ground, and do the roof right so it doesn't push the walls apart.

    This would also not pass building codes in Canada and most other countries with decent building regs :)

    But you wonderful people have marsupials. Do you have "pocket" doors?

    you sure you have the right country? New Zealand, not Australia (also, yes pocket doors! Where else do you store your cat fluff!)

    Move to a "Free State". When I built my house, I did not have to have any permits or inspections.

    No thanks , i prefer my buildings to not fall down around me :)

    What are your building codes ? Why doesnt this work


    Building in New Zealand is governed by the Building Code and by NZS 3604:2011 (Timber-framed building standard.)

    This instructable infringes the NZ standard in so many ways that it would not pass initial scrutiny by a Local Authority if a Building Consent application was to be lodged.

    A few points -

    1) The joists are too close to the ground, are attached to the boundary "bearer" with nails in shear and have no approved metal hangers.
    2) Foundations can be either a concrete slab with footings and steel reinforcing to suit the site or piles (set in concrete) which support bearers which in turn support the joists. A "pole" building such as this does not comply.
    3) Wall framing must be by way of studs (size and spacing to NZS 3604) - a building of this sizs would need guaged 100mm x 50mm studs. Walings fixed to posts to support cladding is not acceptable for a habitable building. The entire floor, walls,roof and cladding on this instructable are supported by coach screws in shear.
    4) The rafters are not connected be either ceiling joists or collar ties to prevent the walls being forced apart under live roof loads.
    5) There are no moisture barriers in floor, walls or roof.
    6) There appears to be no head flashings to the joinery.
    7) Bracing, under the code, is inadequate for wind and earthquake.

    I do not suggest that the building causes danger to its occupants - just that the NZ viewer was thinking of building it in their yard and by doing so would cause much trouble for themselves.

    No - not really. It just means that tried and tested building methods are used -, which perform well in our local conditions. In addition a structure which requires a Building Consent can only be built by a Licensed Building Practitioner (tradesman carpenter).

    That's correct - you can't build yourself. You can assist a Licensed Building Practitioner who oversees your work and who must sign off all the works before a Code of Compliance Certificate is issued at job completion by the Local Authority which issued the Building Consent

    The idea is to protect subsequent building owners by having property records show that the building was constructed to the Building Code by proper use of the Standard..

    Ours is exactly the same if you go to the local government for a permit. It is evident he did not go to get a permit as they would have rejected his drawings. YES, drawings are required in the USA. It's not a swingset. You need drawings for any structure, deck, etc. that involves human beings. He knows nothing and his design is glaring that he does not know.

    And yet I didn't get a permit either. Caught! I'm called a hypocrite. I took the hypo-critic oath. (read some Hypocrates)

    Well I am not a licensed building practitioner here the USA, But I could build this as good or better than a Licensed Practitioner