Electrical house wiring is an art of electrifying a house, from scratch to finish. An estimate is simply a calculated guess of how much materials you will need to finish your project, and how much it will cost you. I have mate a lot of people who ask me how much would it cost me to wire a three-bedroomed house. Most of the time I tell them it depends on how you want your house to be wired. But today I will give a break down on how much it will cost you to wire a standard three-bedroomed house in Zambia.
Steps to take when doing an estimate.
- The first thing to consider is to know how you want your house to be wired.
- Find a qualified electrician or a Technician that can wire a house.
- Explain to either an electrician or a technician what gadgets and appliances that you want to put in your house.
- Then ask a technician to write down the materials that would be needed for your house to be wired.
- Once the materials have been written down, start getting quotations from various hardware outlets.
- When getting quotations to make sure that you get quotes from suppliers who stock genuine and standard material because in Zambia we basically have two types of suppliers.Those who supply substandard materials and those who supply standard material.I recommend that you should always use standard materials.
After considering the steps you should take, to do an electrical estimate for house wiring.I am going to break down for you the stages involved in wiring a house.
Stages or phases of electrical house wiring.
They are basically five stages in electrical house wiring. Therefore, I will list down materials need in each phase of wiring. I am doing this because I know that not all people can buy all the installation materials at once. Most people would want to buy the installation materials phase by phase. Below is a list of phases to consider.
- Slab tubing
- Chiseling and mounting of boxes
- Electrical wiring
- Installing of final fixtures.
What is slab tubing? I know you may be asking what is this slab tubing. This is the laying of electrical conduit pipes in the slab. Basically this involves the tubing for electrical socket outlets, cooker outlets, telephone, and data socket outlets. I am going to list down materials needed for slab tubing that include telephones and data outlets for a standard three bedroomed house.
- 20mm conduit pipes 2 bundles for socket outlets.
- 25mm conduit pipes 2 bundles for telephones and data outlets.
- 20mm couplings 50 number
- 25mm couplings 50 number
- 250 MLS PVC glue 2 bottles
I am not going to put the price for the materials, because prices fluctuate.
Chiseling and mounting of boxes
At this point, you are done with the slab and you have belt all the walls. This is a phase where you start chiseling walls for you to start to mount the meter box, distribution board, switch boxes and socket boxes, cooker control box and many more points like airconditioning outlets and Dstv sockets or television points. I feel I should mention it here that if you did not do a slab tubing, this is the right time for you to do all the points for sockets, telephone, and data. Below is a list of materials you will need to accomplish this phase.
- Switch boxes(3*3 GI boxes) according to the number switch points.
- 20mm conduit pipes 1 bandle.
- Socket boxes(3*6 GI boxes) according to the number of sockets points.
- 20mm adaptors(male bushes) according to a number of switches and sockets points
- 20mm couplings(female bushes) 30 number.
- Cooker control boxes(3*6 or 6*6GI boxes)according to the number of cooker points
Tubing or laying of conduit pipes is a phase where you are done with roofing and you are looking forward todo your ceiling. Tubing at this stage consists of interlinking of lighting, power, tv, telephone and data circuits. You are simply creating a way through which you will pass your wiring cables. That is from the distribution board to various circuits in the home. Below is a list of the materials that will help you to complete your tubing successfully.
- 20mm conduit pipes one bandle
- 20mm junction boxes 30 numbers. when you do not do slab tubing for your data, telephone power, and television circuits, you will need to increase the number of looping boxes to 60.
- Coupling 20mm 50 numbers.
- 300mls PVC glue 1 bottle.
- Ceiling nails 1Kg(this applies when you use planks for your trasses.)but when you use steel trusses, I recommend that you use PVC cable ties. For a house of this size, tow packets would do.
- 20mm saddles, they can either be PVC or metal.
Electrical wiring estimate.
This is a stage where you start putting cables in the house. At this stage, you are done with tubing of various circuits in a house. Below is a list of circuits to be wired with the estimated materials needed to complete the job.
- 1.5mm squared cable red 4 rolls
- 1.5mm squared cable green 4 rolls
- 1.5mm squared cable black 3 rolls
- 2.5mm squared cable red 2 rolls
- 2.5mm squared cable black 2 rolls
- 2.5mm squared cable green 2 rolls
note that this estimate for cables includes 2 airconditioning points.
Usually, the recommended cable size for this circuit is 6mm squared cable. The exact length of cable for this circuit depends on how far the cooker control point is from the distribution board. Therefore, the electrician will measure the exact length then buy accordingly. You will need to buy three colors, that is Red, Black, and Green.
In geyser circuits, you need to use three colors of cable Red, Black and Green.the cable size is 4mm squared cable as for the exact requirement of cable, your electrician will measure it for you.
This is the circuit that connects your house to the national grid or your electricity utility service provider. Some time back I was using 16mm squared cable, now I use 10mm squares cable because this is what our service provider use as the size for their service cable. Here you will also use three colors, namely red black and green. This circuit includes the earthing system for your house. Your Technician will measure for you the exact length of cable required.
Instaling of final fixtures.
Now that you are done with your wiring, its time to do an estimate for your final fixtures. This is a stage where you start installing your sockets, switches fans, airconditioners cookers geysers, downlights, led strip lights, miniature circuit breakers(mcb) and many other electrical fittings that you intend to install.
The first thing that you should do, is to tell your electrician to count the number of switches, required, sockets. The total number of downlights, the total number of chandeliers.After which you go and get quotations from various hardware shops.
Testing and commissioning.
This is a phase where you have finished your wiring, now you want to know how your works have faired to the set standards. This entails that you verify all the circuits in your installation, making sure that all circuits are properly wired. Why do you do this?
By now you should know that the ultimate go of all tests that are done on a new installation, is to provide safety to both people and equipment. Below is a list of tests that you should conduct before asking your electric utility service provider to supply your power.
- Continuity of ring final conductors
- Continuity of protective conductors
- Earth electrode resistance
- Insulation resistance
- Earth fault loop impedance.
All these tests can be done by the electrician doing the installation. If your electrician is not able to do the tests, you can outsource it.
Is this all it takes to do electrical house wiring estimates?
All in all, you have gathered all the material needed to do electrical house wiring. Now you have a rough idea of how much money you will spend on materials to complete your project. Is this all? I guess not, you will need to add the cost of labor. How much money does your electrician want for doing the installation? In many instances, you will have to negotiate with the installer but as a simple guide, you will need to calculate 30-35% of the total cost of the material. Click here to learn more about wiring estimates.