International Journal of Engineering Trends and Technology (IJETT) – Volume23 Number 1- May 2015
―Pre-engineered Toilet Block Design for Village
Housing”
Neha Patel1, Shraddha Sharma2
1
P.G. Scholar, 2 Asso.Prof.
Civil Engineering Department, BIT, DURG, INDIA
Abstract— Engineers are always looking for ways to increase the
speed and efficiency of construction projects. Here we look at an
economical design and construction of a toilet block for village
houses. In China one company is using pre-fabricated components to
build a 30 storey building in less than three weeks. These
components are built off-site and then pieced together like flat pack
furniture to create the finished building. Systems such as air
conditioning, electrical wiring and the water supply are built into the
components in advance of assembly. With migration into Chinese
cities at extremely high levels it is necessary for engineers to think
outside of the box to develop innovative housing solutions such as
this one. First broadcast on 'Supersized Earth' on BBC1 in November
2012. In India toilet block for village housing is on top priority
because village women have to go to open fields.
shuttering of entire floor is ready. Designed reinforcement is
erected on the made up plinth and it is then enclosed with
shuttering plates. Provisions of openings for doors and
windows are made in the shuttering of walls. The slab
shuttering is designed with flow pipes so that the concrete
slurry poured at slab level runs through entire farm work for
walls and slab. Another video we found on internet depicts
about use of discarded mineral water bottles. Inspired by
above instances we decided to review the existing
construction techniques and building materials and come out
with most viable design of a toilet block to overcome village
women problems.
In the quest of economical and multipurpose solution of the problem
conventional techniques and pre-engineered techniques have been
analysed. Finally pre-engineered technique with modern construction
materials resulted in most feasible solution. The present paper
therefore invites young budding engineers to take up pre-engineered
toilet block making as start-up unit to begin their career as
entrepreneurs. The report will help them in arranging bank finance to
begin the enterprise.
A recent survey of owners of structures identified the
following five best features:
1. Ease of erection
2. Solid construction and strength
3. 100% usable space with no floor or ceiling
obstructions
4. Sleek contemporary appearance
5. Easy interior to finish or insulate
Pre-engineered structures satisfy all the above requirements.
In Pre-engineered design a unique combination of materials
make construction simple and trouble free. The buildings are
designed and erected by people without previous construction
experience. In such constructions, more work is done at the
manufacturing centre and less work on site. In such
construction the building is up in just few days- not weeks,
months or years. Pre-Engineered steel building (PEB) or
Metal building systems with steel roofing are gaining
popularity very fast for the following advantages. Though the
concept is quite old with proven technology in advanced
countries, the concept is still considered almost new in Indian
context therefore proposed village toilet block is designed as
pre-engineered construction concept.
A. Main Design features of Pre-engineered Toilet
Keywords—Toilet design, Septic tank, Biogas digester, Preengineered design
INTRODUCTION
Mr. Narendra Modi, newly elected prime-minister of India, in
his 1st formal address to public form red fort, on Independence
Day celebration, expressed his deep concern about village
women problem. Even after 68 years of independence the
village women have to go to toilet in open fields. Therefore
they have to restrain their body for natural calls till early
morning or late evening when darkness is there. The issue has
received focus of many engineers and architects to take up the
challenge to design an affordable and economical design so
that every village house can be provided with toilet facility.
While surfing on internet for selecting suitable building
materials and construction technology we found a video on
multi-storied building construction technique adopted in
developed countries. The entire construction of superstructure
of the building above a made up plinth is cast in-situ by R.C.C.
Modular design of uniform shuttering plates for walls,
columns, beams and slab are first designed and made ready
before the construction is started. The walls and slab are made
of R.C.C. therefore the casting is done only when the
ISSN: 2231-5381
Pre-Engineered Construction Technology
Block
Following points have been kept in view to arrive at a suitable
design of the toilet block:
1. The design must be simple and all component parts of the
toilet block may be transported to the customer‘s site easily
and assembled within few days.
2. The septic tank design is modified over the conventional
type of requirement. It is adopted as portable biogas digester
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International Journal of Engineering Trends and Technology (IJETT) – Volume23 Number 1- May 2015
having facility to use human excreta as well as animal waste
to produce gas to bring saving in cooking fuel used by
villagers.
3. The materials used in making the toilet walls comprise mild
steel rectangular pipe (40 mm x 25 mm in section) frame
covered with composite panels or it may be Tata corrugated
PVC sheets. Provision for water supply and electrification is
made with in composite material (alloy of aluminium and
PVC) panel.
4. The floor is precast R.C.C. slab with glazed tiles or vinyl
sheet.
B. Size of the Toilet & Sanitary fittings
The toilet room is planned on area 1.2 m x 2 m x 2.80 m. Fig.
(1).The height of the room is kept 2.8 to 3 m. For water supply
PVC pipe and fittings are recommended. The toilet seat can be
Indian style/western commode type. The room has wash basin
with mirror and nahani traps to drain out floor water. The
flooring is made of 0.60 m x 0.60 m superior tiles. On one of
the walls PVC door 1.2m x 2.1 m with a ventilator 1.2m x
0.45m is proposed.
A) For portable toilet room, all walls and roof are assembled
on m. s. rectangular pipes frame with composite material PVC
panels of Tata corrugated sheets fitted with nut-bolts. The
entire assembly can be dismantled and shifted if required.
on both sides. Roof is covered with PVC sheets. On one of
the cast in situ walls PVC Door with ventilator is provided.
C) After the toilet block is made ready, the outlet of toilet pan
is connected to biogas digester and wash basin water is sent to
open drain or a soak pit. The biogas digester has another inlet
also for adding cow-dung slurry to make continuous supply of
kitchen gas.
C. Benefits of Biogas digester as septic tank
1) The wastes thrown out in houses and the premises
including the droppings of birds and dung of animals could be
fed into the digester chamber through the other inlet provided.
Thus the surroundings are kept clean and tidy for hygienic life
of people
2) By making use of the biogas produced from the digester as
cooking fuel, the use of other fuels for cooking, purposes can
be reduced and thereby gain financial benefit.
3) Waste sludge from digester is used as bio manure for
agriculture use of chemical fertilizers can be reduced and the
expenses for the manure can be saved. Quality vegetables and
grains can be produced by the application of bio manure.
Pre-engineered Toilet Block Components
Main components are shown in following fig. (2) and (3)
Inside View of toilet
View of Portable Toilet Block
Fig. (2) Toilet Room connected to a biomass digester
Fig. (3) Precast toilet floor with seat
Design of portable Toilet Block for village houses
View of Portable Toilet Block
Biogas digester & stove
Fig.1. Pre-Engineered Toilet Block
B) For conventional type of toilet block construction Cast in
situ walls 10 cm thick plastic bottles Fig.(2) are used as bricks
laid in 1:4 cement mortar slurry with shuttering of ply board
ISSN: 2231-5381
* Fig. (3) Precast R.C.C. Slab with glazed tiles, Nahani trap
for grey water out let and Orissa Pan (toilet seat), wash basin
etc.
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International Journal of Engineering Trends and Technology (IJETT) – Volume23 Number 1- May 2015
* Out let of toilet seat is connected to a portable septic tank
(Syntex make) 1 m3 capacity.
* Angle iron frame – components pre-engineered size made
with MS pipe 25 mm x 50 mm covered on both sides by PVC
sheets, with nut bolts and screw arrangement for two long and
two short wall panels. One of the long wall panels to carry
wash basin and PVC pipe and tap connection
* The short wall panel carries a door and another one near to
toilet seat carries cistern to flush the seat.
* Similar to wall panel roof is also made up of MS pipe 25
mm x 50 mm covered on both sides by PVC sheets.
* Entire assembly described above is erected on precast floor
after it is transported to work site.
* Toilet floor is placed on murrum platform, 0.60 to 0.75 m
above biomass digester unit to have gravity disposal of toilet
waste in the digester. Fig. (2)
Sanitary fittingsThe toilet room is planned on area 1.2 m x 2m. Fig. (1). the
height of the room is kept 3 m. For water supply PVC pipe
and fittings are recommended. The toilet seat can be Indian
style/western commode type. The room has wash basin with
mirror and nahani traps to drain out floor water. The flooring
is made of 0.60 m x 0.60 m superior tiles. On one of the walls
PVC door 1.2m x 2.1 m with a ventilator 1.2m x 0.45m is
proposed.
* Until recently application of biogas plants have been
confined to rural areas, where villagers have dairy farming as
their main business.
* The innovation in production and marketing methods of
biogas highlighted herein, help in commercialization of preengineered toilets in urban areas also. Thus marketing of
portable units open many new possibilities to commission
biogas plants in residential colonies in towns and even in
metro cities suburb areas.
* The production and management of proposed system of
biogas plants open many new business opportunities in rural
areas to absorb unemployed villagers.
Specification for biogas digester to be used with preengineered toilet Capacity (Ltrs.)
1000 2000 3000 4000 5000
No. of Domestic users
3
Height (mm)
1385 1850 1950 2150 2250
Diameter (mm)
1200 1400 1650 1800 2000
Inlet centre (ram tap
115
115
115
115
115
Outlet centre from top
160
160
160
160
160
Thickness of pipe (mm)
100
100
100
100
100
Air Vent diameter (mm)
50
50
50
50
50
Total Septic Volume (M3)
1.00 2.00 3.00 4.00 5.00
6
10
13
16
Chamber Volume (MJ)
0.67 1.34 2.01 2.68 3.35
A) For portable toilet room, all walls and roof are assembled
0.33 0.66 0.99 1.32 1.65
on angle iron frame with PVC panels fitted with nut-bolts. All Filter Volume (M3)
components are designed on a hand push cart having 4 wheels.
The carriage is 1st sent to the site and assembly of room Bill of Materials – for prototype model
components is done there. The wheels are locked at the site.
The entire assembly can be dismantled and shifted if required. No
Particulars
N L B
D
Qty Remar
.
os
ks
B) For Cast in situ walls 10 cm thick plastic bottles are used
3
A
Precast
cast
1
1
2
0.06
0.14
M
as brick laid in 1:4 cement mortar slurry with shuttering of ply
flooring
.
board on both sides. Roof is covered with PVC sheets. On one
finished
with
2
of the cast in situ walls PVC Door with ventilator is provided.
toilet seats and
C) After the toilet block is made ready, the outlet of toilet pan
vinyl flooring
is connected to biogas digester and wash basin water is sent to
PVC wall
2
1 3
7.2
M2
open drain or a soak pit. The biogas digester has another inlet 1
Panels covered 2
.
3
12
M2
also for adding cow-dung slurry to make continuous supply of
on 25 mm x 50
2
kitchen gas.
mm MS pipes
2
Advantages of Using Biogas digester as septic tank
2
P.V.C. Roof
1
2 1
2.4
M2
* It is the cheapest and cleanliest option as a fuel for cooking,
Panel covered
.
lighting, heating etc. It is very clean gas and generate no
on 25 mm x 50
2
smoke hence completely Environment Friendly. It is not only
mm MS pipes
an Eco friendly alternative source of energy, but also a means
3
P.V.C. Septic
1
1
No.
to produce Organic manure for enriching our Soil.
Tank
Rate for
Alter* The operating cost of Bio Gas plant is very less. It requires 4
composite
native
25 Kg. of Cow dung Slurry for 1 Cu. Mtr. of Bio Gas plant or
material for
say 5to 6 Kg of Kitchen waste / on dry weight basis.
wall panel
* It does not generate bad odour
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International Journal of Engineering Trends and Technology (IJETT) – Volume23 Number 1- May 2015
Abstract of Estimate
No
.
1
2
3
4
5
No.
Particulars
Qty
Rate
Per
Floor of the toilet
block
Seat and cistern and
wash basin
PVC Panels with MS
pipes
Portable P.V.C. Septic
tank
Total
Labour cost 25% of
above
Total Cost
0.1
4
9000
M3
2400
21.
6
1
Amount
In Rs.
1260
600
M
5000
No
.
Credit Points
Points
scored
survey
10
1
Sustainable Site
14
2
Water Efficiency
5
3
3
Energy & Atmosphere
17
7
12960
4
Materials & resources
13
10
5000
5
Indoor Environmental quality
15
10
6
Innovation & design
5
5
7
1/3rd life span Appreciation
12
5
8
CO2 emission & eco-friendly
use of energy systems
Market
appreciation
for
greenness
13
7
6
5
2400
2
Particulars
16620
4165
20785
Total Estimated Cost say = 0.21 lacs. Initially 4 prototype
models must be made
9
*Village toilet construction drawing and Comparative cost
estimate with conventional construction materials is given in
Appendix-I.
The site inspection team would give credit points for
greenness factors out of 100 points sub-divided into 9 heads
shown in above table.
* The buildings are classified for credit points scored
GREENNESS FEATURES OF PREREENGINEERED
TOILET BLOCK
(i) 0 to 5 No green
(ii) 6 to 25 points – weak green,
(iii) 26 to 45 points - fairly green,
(iv) 46 to 70 points - good green and
(v) Above 71 points- excellent green
The inspection team allocated total credit points = 62 out of
100. Therefore proposed pre-engineered toilet block comes
under the category ‗good green‘
CONCLUSION
Village toilet block design is in conformity with green
building standards to provide living comforts, water efficiency
and energy savings.
The cost of Pre-engineered toilet is Rs. 22000/- and that of
conventional type of same size is Rs. 70000/-
Green Building Requirements are:
i) Economic Factors, Energy Efficiency &
ii) Lighting
iii) Water Efficiency, Material Efficiency
iv) Energy efficient biogas digester
v) The construction cost estimate is Rs. 25,000 and with 15%
profit it can be marketed, provided the government does not
impose any extra tax.
* Pre-Engineered design of toilet block brings – 50% water
efficiency by following ways:

The design is eco-friendly and cost effective.

It brings continuous saving in fuel
purposes
1.
Use of Wastewater flow
2.
Use of waste material to produce domestic fuel
3.
Portability – ready to use within 24 hours time of
installation
Demonstrable benefits exist in construction of village toilet
blocks are
To stop open field toilet practice of villagers, Need of
implementation of Pre-engineered toilet design: 15%  in
average total water demand, 20%  in average total
wastewater flow. The greenness of a building is decided on
100 points Measuring Scale
i) Green building benefits are apparent
ii) Expedited installation and biogas production from waste
and easy availability of cow-dung makes the design cost
effective and adoptable.
iii) Proposed toilet block scores 100% Greenness points on
Valuation tally
REFERENCES
[1] Video on Civil Engineering construction & form works
[2] Video on house construction with plastic bottles by
Samarpan Foundation
[3] B.N. Dutta‖Estimating & costing‖.
ISSN: 2231-5381
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for cooking
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in
International Journal of Engineering Trends and Technology (IJETT) – Volume23 Number 1- May 2015
Appendix –I Drawing of Conventional Type of Toilet for estimate
10 cm R.C.C. Slab
20 cm wall
3m
20 cm wall
P.L.
20 cm wall
0.60 m
10 cm partition wall
G.L.
3m
1.2 m
Side View of Toilet Block
10 cm P.C.C. 1:5:8
10 cm sand filling
P.L.
1.2Detail
m
m
drawing of a conventional toilet 2.4
block
10 cm R.C.C. Slab
20 cm wall
20 cm wall
10 cm partition wall
3m
P.L.
1.2 m
10 cm P.C.C. 1:5:8
10 cm sand filling
2.4 m
Walls Construction10 by
Plastic
cm R.C.C.
Slab Bottles
20 cm wall
20 cm wall
10 cm partition wall
ISSN: 2231-5381
P.L.
G.L.
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10 cm P.C.C. 1:5:8
10 cm sand filling
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P.L.
G.L.
International Journal of Engineering Trends and Technology (IJETT) – Volume23 Number 1- May 2015
Appendix – I: Pre-engineered Toilet Construction Quantity Estimate
No.
Particulars
A
Nos.
L
B
D
Qty
Remark
Units
Foundation with Septic Tank
1
Excavation in soft soil
1
2.40
1.20
1.20
3.46
M3
2
Sand filling to level the surface
1
2.40
1.20
0.10
0.29
M3
3
P.C.C. (1:5:8) to prepare base
1
2.40
1.20
0.10
0.29
M3
4
Brick Wall 20 cm thick in 1:8 Mortar
1
7.20
0.20
1.00
1.44
M3
(Total centre line length =2(1.4+2.2)
5
Brick Wall 10 cm thick in 1:6 Mortar
1
1.00
1.20
1.00
1.20
M2
6
Plastering the floor: Small tank
1
1.00
1.00
1.00
1.00
M2
Large Compartment
1
1.90
1.00
1.00
1.90
M2
Walls 3 No. short walls
6
1.00
1.00
1.60
9.60
M2
Long walls Inside
2
1.90
1.00
1.60
6.08
M2
Outside walls above ground level
1
7.20
1.00
0.60
4.32
M2
22.90
M2
Sub total
7
1
2.60
1.40
0.10
0.36
M3
Brick Wall 20 cm thick in 1:8 Mortar
1
7.20
0.20
3.00
4.32
M3
Less Door opening
1
1.20
0.20
2.10
0.50
R.C.C. Slab 10 cm thick (1:2:4)
B
8
Super-Structure
Net Brick work
9
10
3.82
R.C.C. Slab 10 cm thick (1:2:4)
1
2.60
1.40
0.10
0.36
M3
Door lintel
1
1.40
0.20
0.10
0.03
M3
Plastering the walls Inside/outside
2
7.20
1.00
3.00
43.20
M2
Ceiling
1
2.40
1.20
1.00
2.88
M2
46.08
M2
Net Plastering in superstructure
11
Flooring : Glazed tiles on floor
1
1.20
2.00
1.00
2.40
M2
Tiles on walls 0.9 m above floor
1
7.20
1.00
0.90
6.48
M2
8.88
M2
Sub total
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International Journal of Engineering Trends and Technology (IJETT) – Volume23 Number 1- May 2015
Appendix – I: Abstract of Pre-engineered Toilet Construction
Particulars
1
2
QTY
Rate
Per
Amount Rs.
Excavation in soft soil
3.46
280
M3
968.80
Sand filling to level the surface
0.29
630
M3
182.70
3
957.00
Remarks
3
P.C.C. (1:5:8) to prepare base
0.29
3300
M
4
Brick Wall 20 cm thick in 1:8 Mortar
5.26
3400
M3
17884.00
5
Brick Wall 10 cm thick in 1:6 Mortar
1.20
425
M2
510.00
Foundation
& Super
Structure
6
R.C.C. Slab 10 cm thick (1:2:4)
0.75
12400
M3
9300.00
2 Nos
M
2
9657.20
M
2
3108.00
7
Plastering
68.98
8
Floor & Wall Tiels
8.88
9
P.V.C. Door complete with fittings
140
350
1
3500.00
Total
46067.70
Sanitary & Electrical fittings 25%
11516.93
Contractors Profit 25%
11516.93
Total Cost
69101.55
Say
Rs.
70000.00
Graphical Comparison of Pre-engineered Vs Conventional Toilet w.r.to Cost & Greenness scale
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