This document provides a summary of the mechanical and electrical services design for a proposed 2-storey office building. It includes: 1) An analysis of the indirect water supply system to be adopted, including calculations of water demand, pipe sizing, and the design of a 1000L overhead water tank. 2) Design of the drainage system for plumbing fixtures like WC and wash hand basins using CPVC pipes of sizes 50mm and 100mm. 3) The electrical design including lumen design method for lighting layout, MCB selection for power circuits, air conditioning design using rule of thumb method and diversity factors.

1. INTEGRATED BUILDING
STUDIO
BLD 411
BUILDING SERVICES
PREPARED BY
AGOHA CHINONSO DANIEL 170504029

2. This presentation shall outline, analyse and
appraise the design, drawings and calculations
done for the production of the mechanical and
electrical services of a proposed office building
for AAT TECH located at Blk 7, Ayoade
STREET, BAJULAIYE,
Shomolu Local Government.
Lagos State.
INTRODUCTION

3. DESCRIPTION OF BUILDING
THE PROPOSED OFFICE BUILDING IS A
STOREY BUILDING COMPRISING OF A
GROUNDFLOOR AND AN UPPER FLOOR.
THE GROUNDFLOOR CONSIST OF
THREE OFFICES, A RECEPTION AND
TWO TOILETS INCLUDING A STAIRCASE
LEADING TO THE UPPER FLOOR.
THE UPPER FLOOR CONSIST OF A
MANAGER’S OFFICE, CONFERENCE
ROOM AND THREE TOILETS
INCLUDING AN EXTERNAL STAIRCASE
FOR EMERGENCIES AND SMOOTH
FLOW OF TRAFFIC WITHIN THE
BUILDING

4. MECHANICAL SERVICES
PLUMBING
WATER SYSTEM ADOPTED
INDIRECT SYSTEM
THE INDIRECT SYSTEM OF WATER SUPPLY WILL BE
ADOPTED AND RECOMMENDED FOR THE BUILDING DUE TO:
• THE ANTICIPATED WATER DEMAND OF THE BUILDING
• THE PROVISION OF ADEQUATE EMERGENCY STORAGE
THAN THE DIRECT SYSTEM
• THE INCONSISTENCIES OF THE WATER CORPORATION
• THE NEED FOR CLEAN WATER AT ALL TIMES
• RELIABILITY, UNSTEADY POWER SUPPLY AND ALSO
EFFICIENCY
ESTIMATED NUMBER OF PERSONS
THE AVERAGE NUMBER OF PERSONS EXPECTED TO BE IN
THE BUILDING IS 25
• DESIGN INFORMATION
• SOURCE OF WATER
• THE SOURCE OF WATER TO THE
BUILDING IS A BOREHOLE
CONSTRUCTED IN THE SITE. WATER
IS THEN TRANSFERRED TO THE
OVERHEAD TANK VIA A
1.5HORSE.POWER WATER PUMP.

5. CALCULATION OF FLOWRATE
ASSUMPTIONS
ALL SANITARY APPLIANCES ARE USED AT THE SAME TIME
USING THE RECOMMENDED FLOWRATES FOR VARIOUS SANITARY APPLIANCES AS STATED IN R.H
GREENO
PARAMATERS EXTRACTED FROM
DRAWINGS
NUMBER OF WC CISTERNS  5
NUMBER OF HAND BASINS  5
FROM THE TABLE ON THE RIGHT
FLOWRATES FOR THE APPLIANCES TO
BE USED ARE 0.11 (WC CISTERNS) AND
0.15(HAND BASINS)
FLOWRATES = ( 5 × 0.11) + ( 5 × 0.15)
= 0.55 + 0.75
= 1.30 LITRES/SEC
SANITARY APPLIANCES FLOWRATES IN LITRES
PER SECONDS
WC Cistern 0.11
Hand Basin 0.15
Hand Basin (Spray Tap) 0.03
Bath (19mm tap) 0.30
Bath (25mm tap) 0.60
Shower 0.11
Sink (13mm tap) 0.19
Sink (19mm tap) 0.30
Sink (25mm tap) 0.40

6. CALCULATION OF BORE DIAMETER
DETERMINATION OF BORE
DIAMETER USING THOMAS BOX
FORMULA
THIS AIDS IN THE PROPER RECOMMENDATION
AND SELECTION OF THE RIGHT BORE DIAMETER
OF PIPE THE PUMP TO THE OVERHEAD TANK.
𝑑 =
5 𝑞2×25×𝐿×105
𝐻
WHERE: 𝑑 = DIAMETER BORE OF PIPE MM
Q = FLOW RATE (L/S)
H = HEAD OR PRESSURE (M)
L = EFFECTIVE LENGTH OF PIPE (M)
(ACTUAL LENGTH ALLOWANCE FOR BENDS,
TEES, ETC.)
PARAMETERS
Q = 1.30 LITRES/SEC
H = 6.986M
L = 21.48M
𝑑 =
5 1.302 × 25 × 21.48 × 105
6.986
= 27MM
THE NEAREST COMMERCIAL SIZE ABOVE THIS
IS 32 MM BORE PIPE DIAMETER

7. EFFECTIVE PIPE
LENGTH
THIS COMPRISES OF THE
SUMMATION OF PIPE LENGTHS
AND APPROXIMATE EQUIVALENT
PIPE LENGTHS OF FITTINGS USED IN
THE CONNECTION FROM THE PUMP
TO THE OVERHEAD TANK
FROM THE EXTRACTED DRAWING
ON THE RIGHT. IT CAN BE
DEDUCED THE LENGTH OF PIPE
WHICH WILL BE USED TO
CALCULATE THE EFFECTIVE PIPE
LENGTH IN THE NEXT SLIDE.
L1 = 6880MM
L2 = 202MM

8. CALCULATION OF EFFECTIVE PIPE
LENGTH
APPROXIMATE EQUIVALENT PIPE LENGTH
APPROXIMATE EQUIVALENT PIPE LENGTHS OF
THE FITTINGS USED GOTTEN FROM THE TABLE
RECALL, PIPE BORE DIAMETER = 32MM
ELBOW  1.4M
STOP VALVE  13M
THERERFORE, EQUIVALENT PIPE LENGTH (L)
BECOMES
L = ACTUAL LENGTH + ALLOWANCE FOR
BENDS,TEES (EQUIVALENGTH
PIPE LENGTH)
L = 6.880M + 0.202M + 1.4M + 13M
L = 21.48M
PIPE BORE
(mm)
ELBOW(m) TEE(m) STOP
VALVE(m)
15 0.6 0.7 4.5
20 0.8 1.0 7
25 1.0 1.5 10
32 1.4 2.0 13
40 1.7 2.5 16
50 2.3 3.5 22

9. DESIGN OF OVERHEAD TANK
ASSUMPTIONS
• SINCE THE BUILDING IS AN OFFICE BUILDING, 40 LITRES
PER PERSON IS ESTIMATED FOR THE PROPOSED
CALCULATION OF THE TANK CAPACITY
• NUMBER OF USERS PER DAY = 25 PEOPLE
• LITRES OF WATER PER DAY = 25 × 40 = 1000 LITRES
PER DAY
• WORKING HOURS ARE BETWEEN 9AM TO 4PM DAILY
HENCE WATER IS ACTIVELY NEEDED FOR ONLY 7 HOURS
DAILY
• FOR 12HOURS USAGE DAILY ,
• LITRES OF WATER : 1000 LITRES  24HRS
? LITRES  7HRS
? =
1000
24
× 7
= 292 LITRES NEEDED PER DAY
ASSUMING THREE DAYS WATER STORAGE
• FOR THREE DAYS = 3 × 292 LITRES = 876 LITRES
• THEREFORE, 1 NO OF 1000 LITRES WATER STORAGE
TANK BE PLACED BEHIND THE BUILDING WITH
• THE SUPPLY FROM THE OVERHEAD TANK
PROVIDES ADEQUATE PRESSURE ALL
THROUGH THE DAY. AND THE WATER IN
THE TANK SHOULD PUMPED AT EVERY
THREE DAYS INTERVAL.
• THE STORAGE TANKS SHALL BE INSTALLED
ON A STEEL TOWER AT A DISTANCE AWAY
FROM THE BUILDING AT AN ELEVATION OF
ABOUT 6.8M ABOVE THE GROUND LEVEL.
TIME TAKEN TO FILL TANK
• CAPACITY OF OVERHEAD TANKS =
1000LITRES
• FLOW RATE OF PUMP = 1.30L/S
= 1.30 × 60
= 78 L/MINS
TIME TO FILL OVERHEAD TANK =
1000𝑙
78𝑙/𝑚𝑖𝑛𝑠
= 12 MINS

10. PLUMBING FIXTURES IN THE BUILDING
PIPE SIZING PLUMBING
• PIPE WORK FROM OVERHEAD
TANK FOR DISTRIBUTION TO THE
BUILDING - 32MMΦUPVC PIPE
• TO WASH HAND BASIN -
15MMΦCPVC BASIN BRANCH
WATER SUPPLY PIPE
• TO WC -
15MMΦCPVC WC BRANCH SUPPLY
PIPE
• RISER PIPE (COLD WATER) -
32MMΦ CPVC (COLD WATER)
SUPPLY PIPE
FIXTURES/FITTINGS
DESCRIPTION
LOCATION SPECIFICATIO
N
GROUN
D
FLOOR
UPPER
FLOOR
EXTERNA
L
TOTAL
Water
closet
Close couple
Twyford WC set
with “p” trap,
complete with all
necessary fittings
2 3 - 5 TWYFORD
CERAMIC
SNW-100041
Wash
hand
basin
Wash hand basin
with trap with all
necessary fittings
2 3 - 5 TWYFORD
CERAMIC
SNW 100096
90o
Elbow
Used to pipes at
perpendicular edges
8 9 6 17 PVC
Tees 3 4 - 7 PVC
Ball
valve
4 7 - 11
Stop
valve
2 2
Flexible
connect
or
4 6 10

11. DRAINAGE FIXTURES IN THE BUILDING
PIPE SIZING DRAINAGE
WATER DRAINAGE FROM THE BUILDING
WASH HAND BASIN – 50MM PVC 3MM
THICK
WC – 100MM PVC 5MM THICK FOR FOUL
WASTE
INSPECTION CHAMBER IS PROVIDED AT
EVERY CHANGE IN DIRECTION ALSO IT IS
450 X 450MM IN SIZE WITH A 4 INCH WALL
IN BETWEEN TO SEPARATE THE FOUL/SOIL
WATER FROM THE WASTE WATER.
FLOOR DRAIN STACK – 50MMΦ CPVC PIPE
PROPERLY FIXED TO THE WALL
WASH HAND BASIN – 50MMΦ CPVC PIPE
WC DRAIN – 100MMΦ CPVC PIPE 5MM
THICK
WC STACK – 100MMΦ CPVC PIPE
FIXTURES/FITTINGS
DESCRIPTION
LOCATION SPECIFICATIO
N
GROUN
D
FLOOR
UPPER
FLOOR
EXTERNA
L
TOTAL
Water
closet
Close couple
Twyford WC set
with “p” trap,
complete with all
necessary fittings
2 3 - 5 TWYFORD
CERAMIC
SNW-100041
Wash
hand
basin
Wash hand basin
with trap with all
necessary fittings
2 3 - 5 TWYFORD
CERAMIC
SNW 100096
90o
Elbow
Used to pipes at
perpendicular
edges
8 9 6 17 UPVC
100025
Vent Pipe 2 3 - 5 UPVC
Inspectio
n
Chamber
Casted Precast 3 - - 3 PLAIN CONCRETE
Septic
Tank
Casted Precast - - - 1 PLAIN CONCRETE
Soak
Away
Casted Precast - - 1 1 PLAIN CONCRETE

12. ELECTRICAL SERVICES
• LIGHTING DESIGN- THE LUMEN
DESIGN METHOD WAS USE TO
DETERMINE THE LIGHTING LAYOUT
THAT WILL PROVIDE THE REQUIRED
ILLUMINANCE IN EACH ROOM.
• POWER CIRCUIT- THE DESIGN OF
THE POWER CIRCUIT IS BASE ON
THE ANTICIPATED APPLIANCE
LOADINGS APPLYING THE RING
CIRCUIT CONSIDERATION
• AIR CONDITIONING CIRCUIT- THE
DESIGN ADOPTED WAS THE RULE OF
THUMB METHOD OF DESIGN.
• DESIGN INFORMATION
ELECTRICAL UTILITY DESIGN
MODE OF SUPPLY- SUPPLY FROM THE ELECTRICAL
SUPPLY AUTHORITY TO ELECTRICAL POLE OF
THREE PHASE 4 WIRE FROM A SECONDARY
DISTRIBUTION TRANSFORMER.
SUPPLY TYPE SYSTEM TO THE BUILDING- THREE
PHASE METER 4 WIRE OF 415V SUPPLY TO THE
WHOLE BUILDING FROM A THREE PHASE 4 WIRE
FROM A SECONDARY DISTRIBUTION
TRANSFORMER.
SUPPLY SYSTEM TO EACH FLOOR OF THE
BUILDING- SINGLE PHASE 3 WIRES OF 220V
SUPPLY TO EACH FLOOR.
DISTRIBUTION BOARD- TYPE 100A TPN 5 WAY
MCB DISTRIBUTION BOARD TO EACH FLOOR AND
EXTERNAL SURROUNDINGS

13. LIGHTING DESIGN
• LIGHTING DESIGN- THE LUMEN
DESIGN METHOD WAS USE TO
DETERMINE THE LIGHTING LAYOUT
THAT WILL PROVIDE THE REQUIRED
ILLUMINANCE IN EACH ROOM.
• 𝑁 =
𝐸𝐴
𝑛 ×𝑓 ×𝑀𝑓 ×𝑈𝑓
where: E= required illuminance
A = area to be lit
N = no of illuminance required
n = no of lamps per lumen
F = lumen rating of the light
builb
Mf = maintenance factor[light loss. this
depends on the maintenance of the
𝑅𝑂𝑂𝑀 𝐼𝑁𝐷𝐸𝑋 =
𝐿 × 𝑊
𝐻𝑚(𝐿 + 𝑊)
where ; L = length of space
w = width of space
Hm = mounting height
The room index is used to obtain the
utilization factor from a table shown in
the report.

14. CIRCUIT AND MCBs
THE TABLE ON THE RIGHT SHOWS THE
RESPECTIVE CIRCUITS IN THIS DESIGN
AND THEIR RECOMMENDED MCB.
LC1 REPRESENTS ALL LIGHTING
FIXTURES ON GROUNDFLOOR
RC1 REPRESENTS APPLIANCES ON
GROUNDFLOR EXCEPT AIRCONDITIONS
AND REFRIGERATOR
AC1 REPRESENTS ALL AIRCONDITIONS
ON THE GROUNDFLOOR
SC1 REPRESENTS WATER HEATER
CIRCUIT CURRENT
FLOWING (AMP)
RECOMMEND
MCB (AMP)
LC1 3.71 4
LC2 3.86 4
LC3 7.78 10
RC1 19.94 20
RC2 22.06 25
RC3 31.38 32
RC4 14.67 16
AC1 14.67 16
AC2 11.28 13
SC1 8.18 10

15. AIR CONDITION DESIGN
HORSE POWER - HEAT LOAD RELATIONSHIP
AIR CONDITION DESIGN
IN THE DESIGN OF THE PROPOSED OFFICE DEVELOPMENT
RULE OF THUMB WAS CONSIDERED AND USED TO DESIGN
THE COOLING CAPACITY OF THE VARIOUS SPACES WITHIN
THE BUILDING
BELOW IS A TYPICAL EXAMPLE OF THE DESIGN OF OFFICE
SPACE 1- USING THE RULE OF THUMB
PARAMETERS TO BE CONSIDERED IN THE DESIGN OF
AIR CONDITION
LENGTH: 4.463M BREADTH: 3.263MHEIGHT: 2.85M
AREA OF SPACE = 4.463 × 3.263 = 14.563M2
VOLUME OF SPACE TO BE COOLED = AREA × HEIGHT =
14.563 × 2.85
= 41.51M3
RECALL,
1 M3  225 BTU
41.51M3 ? BTU
? BTU =
41.51M3
1M3 × 225𝐵𝑇𝑈
= 9339.75BTU
FROM TABLE IT CAN BE DEDUCED THAT 9339.75BTU
VOLUME RELATIONSHIP
1 M3  225 BTU
POWER [WATTAGE] – HORSE POWER RELATIONSHIP
1.0 HP  717.5W
1.5 HP  1076.25W
2.0 HP  1435W
CURRENT CONSUMPTION
1.5HP =
1076.25W
220
= 4.89 AMPS
NUMBER OF AIRCONDITION UNITS FOR THE OFFICE SPACE 1
SINCE 1.5HP SUPPLIES 13500BTU/HR, AND THE SPACE
REQUIRES 9339.75BTU/HR
N =
9339.75
13500
= 0.69 = 1
THEREFORE 1 NUMBER OF 1.5HP IS REQUIRED FOR THE
HORSE POWER (Hp) HEAT LOAD (BTU/hr)
1.0 Hp AC 9000
1.5 Hp AC 13500
2.0 Hp AC 18000

16. DIVERSITY FACTORS
• DIVERSITY FACTOR
CIRCUIT CONDITION DIVERSITY FACTOR (Amp)
LIGHTING 66% of total Current demand 0.66 × [3.71 + 3.86 + 7.78]
0.66 × 15.35
10.13
POWER 100% of highest full load
current + 40% of remainder
1(31.38) + 0.4(19.94 + 27.06
+11.28 + 14.67 + 14.67)
= 64.43
WATER HEATER 100% of Load 8.18

17. CABLE SIZING
• LIGHTING DESIGN- THE LUMEN DESIGN
METHOD WAS USE TO DETERMINE THE
LIGHTING LAYOUT THAT WILL PROVIDE
THE REQUIRED ILLUMINANCE IN EACH
ROOM.
• POWER CIRCUIT- THE DESIGN OF THE
POWER CIRCUIT IS BASE ON THE
ANTICIPATED APPLIANCE LOADINGS
APPLYING THE RING CIRCUIT
CONSIDERATION
• AIR CONDITIONING CIRCUIT- THE
DESIGN ADOPTED WAS THE RULE OF
THUMB METHOD OF DESIGN AS SEEN IN
THE PREVIOUS SLIDE
C.S.A (mm2) CURRENT
CARRYING
CAPACITY
(CONDUIT)
VOLTAGE
DROP (Mv )
1.0 13.0 44.0
1.5 16.5 29.0
2.5 23.0 18.0
4.0 30.0 11.0
6.0 32.0 7.3
10 38.0 4.4

18. CABLE SIZING
BELOW IS A TYPICAL EXAMPLE OF THE CABLE
SIZING OF LC1
𝑉𝐷 =
𝑚𝑉 × 𝐶𝑢𝑟𝑟𝑒𝑛𝑡 𝑓𝑙𝑜𝑤𝑖𝑛𝑔 × 𝐶𝑎𝑏𝑙𝑒 𝑙𝑒𝑛𝑔𝑡ℎ
1000
≤ 4% 𝑜𝑓 220𝑣 (8.8𝑣)
• FOR LC1
RECOMMENDED C.S.A = 1.0 MM2
CURRENT FLOWING =3.71AMPS
𝑉𝐷 =
44 × 3.71 × 43.52
1000
= 7.10𝑣 ≤ 8.8𝑣
THEREFORE 1MM2 CABLE SIZE IS
SATISFACTORY AND THUS RECOMMENDED
C.S.A (mm2) CURRENT
CARRYING
CAPACITY
(CONDUIT)
VOLTAGE
DROP (mV )
1.0 13.0 44.0
1.5 16.5 29.0
2.5 23.0 18.0
4.0 30.0 11.0
6.0 32.0 7.3
10 38.0 4.4