Toilet Planning

Posted by on Aug 31, 2010 in Life Support Systems, Work | No Comments
Toilet Planning

Planning the Toilet.

When we first arrived here, the long drop was completely full. Strange as it seems now, we were straight out of India, this didn't bother us too much and considered it a luxury not to have someone watching. We had a blank slate to start. I was new to making compost and I wouldn't recommend to anyone else trying for their first time to get a pile going to use their shit.

There is a bit of an art to it, it isn't difficult by any means but there is a knack and a few tricks to getting it right.


We needed something immediately for our daily function. I was referred a book by a friend and very quickly was using the bucket technique espoused so eloquently by Sir Joseph Jenkins in his timeless classic "The Humanure Handbook". He isn't really a knight, but is absolutely deserving of the high honours of the planet & society.


The bucket system has it's limitations though. Several key problems arose.

Firstly was the labour of making the compost and the necessity for each batch to go well. Then there was the issue of visitors who were not familiar and quite uncomfortable with the concept, we wanted people to be accepting of humanure composting, and that wasn't going to happen by throwing them in the shallow end of a shit bucket.


The last was that it is illegal to have such a system and that was an argument that we didn't want to have with the local council. So we continued to brainstorm ideas, research and experience composting toilets around the area. We are lucky, this is one of the pioneering areas of the concept.


There are a lot of examples and several generations of design as the flaws were worked out. We like to think visually, so I made a mind map. toiletPlanning Compost Toilet pres mindmap We finally settled on the double concrete chamber batch model. 

It's key feature is that the owner never need come into contact with raw material. When one chamber is filled, it is sealed and left until the other is full. This can take over 18 months for two people, by that time the ingredients are well decomposed.


From above it can be made as respectable as any flush toilet room and it is very unlikely that the user is exposed to their deposit as the chamber is dark (this can be a limitation for those that like to inspect).

Finally if it is adequately sealed and the final product is buried council is quite happy.

With all our requirements met, we set about it. We acquired the plans from a local fellow named Ray Flanagan, who can be contacted at [email protected]

They are very comprehensive and we can highly recommend getting them. He has given me permission to post this sample image. toiletplans3

Next we called around for local builders who were familiar with the design. I ordered the materials listed in the construction plans and had them delivered. For the next step of this project see Composting Toilet in the Systems Page.


Composting Toilettimeline


I kept records of the materials and their cost. It is separated into the two phases of the project, the composting chambers and the timber frame.


Toilet Chambers 2 cubic meters of compost storage with besa brick walls and floating slab floor.


Material Quality Length (mm) Purpose Quantity Price per Sub-Total Supplier Date Supplied
100×100 Besa Block Standard 100 Chamber Walls 100 1.68 $168.00 Mills Transport 11/07/2006
100 mm 3/4 Besa Blocks     Chamber Walls 5 1.54 $7.70 Mills Transport 11/07/2006
100 mm 1/2 Besa Blocks     Chamber Walls 12 1.38 $16.56 Mills Transport 11/07/2006
100 mm corner Blocks     Chamber Walls 4 2.60 $10.40 Mills Transport 11/07/2006
River Sand washed   Concrete 1 50 $50.00 Mills Transport 11/07/2006
Cement GP 20kg     Concrete 10 10 $100.00 Mills Transport 11/07/2006
Blue Metal Gravel Stones     Concrete 2 30 $60.00 Mills Transport  
3 Bar F8 Trench Mesh   5000 Foundation 2 25 $50.00 Norco 10/07/2006
10mm Threaded Rod Galvanised 2400 Tie Downs 2 18 $36.00 Norco 10/07/2006
F72 Mesh   2400×6000 Slab Reinforcement 1 67.5 $67.50 Norco 10/07/2006
PVC Storm Water 90mm   6000 Flue Vent 1 21 $21.00 Norco 10/07/2006
50 x 25 x 4mm Wire mesh Galvanised 2000 x 1200 False Floor 2 30 $60.00 Norco 10/07/2006
Reinforcing Rod R10   6000 Tie Chamber Walls 2 20 $40.00 Norco 10/07/2006
Total Cost $687.16    



Once the chambers were complete and we had overcome the difficulties of floating the slab we were onto the upstairs section, or as I came to know it the toilet house. First I drew up clear plans using the only construction technique I was familiar with “post & beam”.






I took these to a friend, who told me that the post and beam was unnecessary in this case as the wall frames could hold the roof up (& down). So I redrew the plans, this time including the option to connect to the house via a covered walkway.



Unfortunately these plans lacked the detail needed to actually build them. At this point, I'd had enough of drawing and redrawing and decided it was an excellent opportunity for me further develop my skills in the free 3d modelling software called Google Sketch-up .


I'd tried sketchup once before, but the time wasn't right and i'd got frustrated at the process of learning something new and felt that I could draw it quicker. I used the software to make it as I wanted it and then could alter the design easily. I initially sketched out the model to be roof style neutral.


Toiletweb  019 Toiletweb  018


From there I added the more complex gable style roof as a new layer.


Toiletweb  020


Toiletweb  021


Toiletweb  022 Toiletplan7


Upon looking at the images, I decided that the gable roof would add too much complexity to the initial build and any future effort to join it to the house via the covered walk way. So I removed that roof and added a simple shed style instead.




Now that I was happy with the design, I added the necessary detail in order to build it.






With that in place we organised for some local carpenters to come over and help us put it all together. See the Compost Toilet in Systems for more details of the construction. Here are the costings for the upstairs toilet house.


Toilet Hardwood Timber Frame House with Colorbond Roof

Material Quality Length (mm) Purpose Quantity Price per Sub Total Supplier Date Supplied
"50 x 100 HW (2×4"") " Rough Sawn 3200 Rafters 3 5.5 $52.80 Nimbin Building Supplies 05/09/2008
"50 x 100 HW (2×4"") " Rough Sawn 2300 Wall Frames 13 5.5 $164.45 Nimbin Building Supplies 06/09/2008
"50 x 100 HW (2×4"") " Rough Sawn 1600 Wall Frames & Bracing 10 5.5 $88.00 Nimbin Building Supplies 07/09/2008
"50 x 100 HW (2×4"") " Rough Sawn 500 Studs 7 5.5 $19.25 Nimbin Building Supplies 08/09/2008
"37.5 x 75 HW (3×1.5"")" Rough Sawn 2600 Battens 5 2.85 $37.05 Nimbin Building Supplies 08/09/2008
2400 x 1200 OSB Sheet   - Bracing 2 23.5 $47.00 Nimbin Building Supplies 08/09/2008
1060×1080 Sheet Metal Gal 1.2 Door to Chambers 2 54 $108.00 Nimbin Building Supplies 08/09/2008
Green Orb colourbond steel   3300 Roofing Sheets 4 10 $132.00 John Holborn 15/09/2008
Standard Profile   2200 Wall cladding 4 10 $88.00 John Holborn 16/09/2008
Batten Screw Fasteners Galvanised 75 Fasten Battens 50   $25.00 Bolt Barn Lismore 08/09/2008
Strapping Galvanised 1000 Framing 1 5 $5.00 Bolt Barn Lismore 09/09/2008
Tek Roofing Screws Galvanised 75 tie roof to battens 100   $20.00 Bolt Barn Lismore 10/09/2008
Nails Galvanised 100 Framing 200   $20.00 Bolt Barn Lismore 11/09/2008
Triple Grips Galvanised   Tie rafters to wall frames 6   $10.00 Bolt Barn Lismore 12/09/2008
Dynabolts Galvanised 125 tie frame to concrete floor 8   $18.00 Bolt Barn Lismore 13/09/2008
1220mm Aluminium Fly Screen   7000 Screen window + gaps 1 12 $84.00 Bunnings 15/10/2008
Total Cost $918.55