# Estimating and Costing of materials required for House Wiring or residential plan

## Estimating and Costing of materials required for House Wiring or residential plan

Hello everyone, in this article I will discuss the estimation and cost of the lighting circuit and heating circuit for house wiring or residential plan.

Before starting the article if you want to watch a video related to electrical estimation and costing, you can watch my YouTube videos - Click Here

### Given data: Consider the given residential plan.

This is the plan where we should calculate everything i.e., what are the materials required for the plan and make a chat of materials with costing.

All dimensions are in a meter

The following assumptions are made :

•  The height of the meter board, distribution board from the floor level = 2 meters.
•  Height of horizontal run and lighting fitting from floor level = 3 meters.
•  Height of switchboard from floor level = 1.5 meters.

#### Step-01

Total lighting load and number of circuits

 SI.NO Location Area(meter square) Wattage (10W/m sq) No of points Types of fitting lights fans socket 01 Verandah 8 80 1×60 - - Pendent 02 Room 12 120 1×40(FL) 1×80 1×60 Pendent 1×60(IL) batten 03 Hall 16 160 2×40 1×80 1×60 Pendent 1×60 & batten 04 Kitchen 9 90 1×40 - PS=2000 Pendent 1×60 & batten 05 Passage 1.5 15 1×60 - PS=1000 Pendent 06 Bath roon 2.5 2.5 1×60 - Pendent Total load = 480w 160w 120w

Total lighting circuit load = 480 + 160 + 120 = 760 watts

Total heating circuit load = 3000 watts

Total load of Installation = 760 + 3000 = 3760 watts

No of the lighting circuit
=  760/800 = 0.95

If the total lighting circuit load exceeds 800 watts then two circuits must be provided, but here total lighting circuit load is less than 800 watts.

Therefore, only one circuit is used.

Hence from the Meter board, one lighting and one heating circuit are taken.

#### Step-02

Wiring diagram for the given plan:
MB - Meter Board
DB - Distribution Board
SB - Switch Board contains switches & sockets

#### Step-03 :

Size of the wire

To calculate any size of the wire, first we should calculate load current and by using a wire table size of the wire can be calculated.

= 760/230 = 3.30 Amps
let, a factor of safety be 2(for future demands or load)

Current rating = load current * 2
= 3.30 * 2 = 6.6 Amps

Therefore, for lighting circuit 3/22 SWG copper wire is selected from the wire table

#### Step-04:

Length of Conduit required, use concealed conduit system of wiring.

 SI.NO Location Horizontal run Vertical drop to switch Vertical rise pipe line to ceiling fan Wall crossing Total 01 Verandah 4+2 - 0.5 6.5 02 Room 3+2 1 0.5 6.5 03 Kitchen 3+1.5 1 0.5 6 04 Hall 4+4+4 1 0.5 0.33 * 5 = 1.65 (overall) 12 05 Passage 1+1.5+0.75 1 0.5 3.25 06 Bath 1.25 1 0.5 2.75 Total 1.65 37

Total = 37 + 1,65( wall crossing )
= 38.65 = 39 (say)

Total PVC conduit = 39 +5% wastage
= 40.95 = 41 meter  (say)

#### Step-05:

The total length of wire required

length of wire(3/22 copper wire) = 41 * 3
= 123 meter

#### Step-06:

Wood screws(assorted size) = 4(No of MB+SB)
= 4(1 + 4)
= 20 + 5% wastage
= 21.95 Nos

#### Step-07:

The number of wood plugs required is  22 Nos as same as wood screws.

#### Step-08:

Other accessories required

01. ICDP Switch

load current = 3.30 * 2 = 6.6 Amps
A 15A ICDP switch is selected or 15A MCB is used.

02. Switches = No of lamps + fans + sockets
= 12 + 2
= 14 Nos
A 250 V, 5 A switches = 14Nos

03. A 250 volts, 5 A, 3-Pin socket = 2 Nos
04. No of fan regulators = 2 Nos
05. No of Pendant holder = 6 Nos
06. No of Angle holder = 4 Nos
07. No of ceiling roses = No of fan + No of pendant
= 2 + 6 = 8 Nos
08. Fluorescent fitting, 230 V, 5 A = 4 set
09. Ceiling fans, 230 V = 2 set
10. Incandescent fitting = 6 set
11. No of Tees = 4 Nos
12. Meter Board = 1 Nos
13. Switch Board = 4 Nos

#### Step-09:

Labor Charge

The labor charge depends upon the number of points

No of point
= (lights + fan + sockets) * 0.5 + MB + DB
= (10 + 2 + 2) * 0.5 + 1 + 1
= 15 Nos

Labor Cost = Cost per point * No of points
= 195 * 15 = Rs 2970.00

### Cost of Materials

= 3000 / 230 = 13.04 Amps

Current rating = load current * Factor of safety
= 13.04 * 2 = 26.08 Amps

Therefore, 7/20 SWG copper wire is selected.

### 02. PVC Conduit required

Horizontal run = 4+2+4+1+2.5+1.5+3
= 18 meter
Vertical drop = 1+1 = 2 meter
Wall crossing = 0.33 * 4 = 1.32 meter
Total PVC Conduit = 21.32 = 22 (25mm, 2mm thick)

Therefore, Total PVC conduit = 22 + 10% wastage
= 24.2 = 25 meter

### 03. Length of wire required

Length of wire = 3 * length of PVC conduit
= 3 * 25
= 75 meter

### 04. Wood screws (assorted size) = 4 * 2

= 8 No + 5%
= 8.4 = 9 No's

### 06. Other accessories required

(a) ICDP Switch
Load current = 13.04, FOS = 3
Current rating = 13.04 * 3 = 39.13 Amps
A 250 V, 50 Amps selected

(b) Switches - A 250 V, 15 A switches = 2 No's
(c) 3-Pin socket = 2 No's
(d) No of elbows = 2 No's
(e) Switch board (200*250*45 mm) = 2 No's

### 07. Labor Cost

No of point = 2
labor cost = 195 * 2 = 390