Main idea behind this design is to make construction cheap & easy.
You would need:
Wooden laths (cheapest kind) - amount depending on how big you want the dome
Some-kind of pincers
Fence wire (soft)
Small clip/nail/clamp gun
Plastic film roll - about 8m x 2.5m
Some thread and anchors (bricks) for stabilization
Wide transparent tape
1-2liter Varnish & brush
Color sticky markers (for ease of construction)
Scissors / Cutting knife
For window (x times how many you want):
Small Hinges x2
Wider wooden laths for covering gaps around border
Small Hinges x 2
Furniture magnets 1-3
Furniture metal corners x 8 (4 for doors, 4 for frame)
Wider wooden laths for covering gaps around border
Soil & seeds or plants
Total costs for me were about: 80 EUR = ~ 105 USD
Greenhouse has been standing well since beginning of the summer
Step 1: Cutting Wooden Laths
You would need to cut 3 types of wooden laths
For calculations I recommend to use this site (I built 5/8 size):
High precision is not necessary (+/- 5mm)
For example for 1.5m radius (that I had) you would need
A elements 0.522m x 30
B elements 0.605m x 90
C elements 0.618m x 120
You can tweak these numbers in order to get the most out of wooden laths that in my case came in about 2m length.
I advice you to write letter A, B, C with pencil on each stick and tie them together by groups.
I advice sawing trough 4 or more laths at once.
Sawing took for be about 3 hours of work.
Step 2: Drilling Wholes in Both Sides of Sticks
I advice to drill trough 3 or more sticks at once to make process faster.
In my case it took about 2 hours of work
Next using diagram & fence wire start tithing sticks together.
There are 2 types of shapes you would need to make:
Hexagons - with 6 C sticks
Pentagons - with 5 A sticks
All shared borders are B sticks
Start building it upside-down with Pentagon in the middle.
Again precision is not that important at this point. If you mix something up it is relatively easy to take it apart and fix it.
I advice you to use color sticky markers in order to keep track of shapes.
Assembly of dome itself for me took about 3 hours
Step 4: Making Doors
Next you would need to turn structure to correct position sitting on bottom.
If the structure collapses its OK, because you would be able to straighten it out when it is standing.
When it is standing measure as precise as you can doorway and create sides of doors like in images to make frame.
Strengthen frame using metal corners on the corners of frame. It will also make sure it do not deform.
Step 5: Doors, Window and Varnish
Measure and create construction of doors (straighten them in corners with metal corners)
Keep in mind space for hinges and wider lathes around frame of doors (and places for magnets)
Measure and create window as triangle inside other chosen triangle. I strongly advice to have 2 or more windows because this dome-type greenhouse is very humid when it is finished.
You can see my window frame in one of the images below (in corner), but you can improvise your own version. I used thread to tie a handle for it (for use to hold it in open position when it is finished)
After construction varnish everything as well as you can (I advice at least 2 times with a time span in between to dry it), otherwise wood will rot very soon.
Let everything dry for couple of hours day
Step 6: Secure Plastic Film
Make sure it will not be windy day, because wind could blow whole project away like a sail.
Secure plastic film roll using clamp/nail/clamp gun (I do not know exact name of it in english - look in photo)
Start putting on plastic on doors, windows and then start from top to one side of the dome.
Try to secure plastic in pieces as large as possible so you do not need many cuts.
Shoot with gun clamps in wooden frame and streach plastic over. If it is not precise you can fold plastic in rolls that you can nail to frame as well.
Don't worry if there are some holes not covered. You can add cut-off pieces later at the end.
Step 7: Construct Outer Frames of Windows
Add wider wooden laths around frames of doors and windows like in pictures.
Add furniture magnets to doors and windows (if you wish). They work really good and I advice to add one to window as well.
Add handle to doors.
Add hinges to doors and windows and install them to the structure.
Add some extra plastic film around doors and window to avoid wind blowing trough the structure when it is not desirable. If you will have wind draft you could have giant sail in your garden.
Get ready spot for greenhouse (you can measure radius with a string)
Dig out grass around radius and put on new soil.
Dig holes for anchors and get thread and bricks/rocks to construct them.
Next you should be able to pick up whole structure from inside and move it over the new spot. Hold it by the frame.
When you place it on the spot you can arrange disrupted parts and secure it with anchors.
Step 9: Planting
From my experience of growing plants:
Plant fewer plants rather many together - in the end you will have better harvest
Use some organic fertilizer
If you plant tomatoes make sure the soil is right and you have very good ventilation, because they like more air than humid air.
Things that grow well in this kind of greenhouse:
- peppermints & other kind of spices
My plan for next year is to build autonomous ventilation and irrigation system using Arduino or something like that.
You could also build inside some white led lights to have glowing dome in night time.