Requirements and Standards
Electrical design is not an easy task. It requires a lot of expertise. Detailed study is needed prior to installation work. The engineer must consider quality and any specific requirements together with price. Different options are to be examined.
Choice of room utilization, decor, hobbies and the activities of the various residents are now critical to electrical design.
Electrical installation cannot make universal provision for every conceivable arrangement.
Flexible design approach is now often practiced. Standards for the house industry are determined by the National House Building Council (NHBC).
The minimum requirements
The following is an outline of basic requirements for a three-bedroom house with 120m2 floor area. This would be a typical speculative estate development (Figure 2).
- Rooms: small kitchen; dining room; lounge; downstairs cloakroom; main bedroom with en-suite bathroom; second double bedroom; small single bedroom; landing bathroom or shower room;
- Heating: central heating by gas or oil;
- Garden: small garden at both front and rear.
Standards
National House Building Council (NHBC)
The NHBC give minimum standards for living accommodation and services, which are shown in Table 1. It should be noted that houses vary in size and use, so the values given should be considered as a minimum.
Table 1 – NHBC recommendations for a house.
13 A socket-outlets (twin socket count as two outlets)
| Room | Outlets | Notes |
| Kitchen/Utility | 6 | Where homes have separate areas, the kitchen should have a minimum of four outlets and the utility room two. |
| Utility | 3 | Where appliances are provided, at least three outlets should be for general use. |
| Dining room | 3 | |
| Living room | 4 | At one double outlet family room should be near the TV aerial outlet |
| Bedroom | 3 (2) | Three for main bedroom. Two for other bedrooms |
| Landing | 1 | |
| Hall | 1 | |
| Combined rooms should have sockets equal to the sum of the number for individual rooms, with a minimum of seven in the case of kitchen / utility and another room. | ||
| Lighting Every room should have at least one lighting point. Two-way switching should be provided to staircases. | ||
| Smoke detectors For this two-story house, two mains operated, interconnected alarms are required. | ||
Relevant wiring regulations 13 A socket-outlets
- Building Regulations now require socket-outlets, wall switches and other similar accessories to be sited in habitable rooms at appropriate heights of between 450 and 1200mm from the finished floor levels.
- Any socket-outlet with a rated current not exceeding 20 A, which is used by ordinary persons’ equipment for outdoors use must be provided with additional protection by means of a 30mA RCD.
- No 230V sockets, except shaver sockets complying with BS EN 61558-2 are permissible in bathrooms and shower rooms.
- 230V socket-outlets must be located at least 3m outside the boundary of zone 1 and provided with 30mA RCD protection.
Lighting
- To avoid danger and inconvenience, there should be more than one lighting circuit.
- In a bathroom, all equipment must be suitable for the zone in which it is installed.
- Wall switches and other accessories must not be installed in zones 0, 1 and 2.
- Cord switches must be installed outside of zones 0, 1 and 2, but the cord may hang within zones 1 and 2.
- There are restrictions on the current-using equipment in zones 0, 1 and 2.
- Equipment that is installed in zones 1 and 2 must have water penetration protection of at least IPX4.
- A careful study of BS 7671: (Most recent version) Section 701 is recommended.
Will be continued soon…
Brister
Good day Sir
Can you please send me the calculations for the entire house-load,circuit breaker ratings and cable sizing.
Thanks in advance
Yaw Adomako
wow is very good but can you send some of your electrical plan ,like 5 rooms wiring plan for me,please
Yusif Saeed Yusif
Tnx for the post,,, but if you could help me please,,I’m an electrician but I find difficulty in calculating the number of materials like 22mm pvc pipes,,,conduit cables etc. For 2,3,4 bedroom houses.. I plead with u to teach me with some examples & samples,, God bless you.
Palanikalvarayan
Hai3 bedroom and livings rooms and3 bathroom and kitchen rooms .total 25 flotation wiring size formula what material list send my mail palanivdm@ Gmail.com for use Oman country .please I am waiting for your reply thanking you
Farhan Zaid
Thank you brother.
sameera
please send me useful articles like this relating to electrical designing.
can you please explain the lighting design software Dialux.
Muhammad Awais Qureshi
Please send me electrical software for made diagram of electrical wiring.
Thanks
IQBAL HUSSAIN
waiting for your next article
electrical engineer
iqbal
isiaka ibrahim
am an undergraduate student of bayero universty kano, level 500. pls i need a well completed project on electrical service design. because i want to wright my final year project on it. thanks
muktari musa
pls can i get some materials from you?
SIVARAJA.T.S
I’m a degree holder B Eng. (Hons) in Electrical Engineering (power) From UTM 2010 (University Technology Malaysia. I would like to continue for my master degree in electrical field on line how shall I go about it?
Need some advice…. Thank you…
yetunde
pls i want know if there are software apart from autocad that be use for electrical building designs that has installed legends and can also calculate the numbers of fluorescent lamps, number of sockets etc for a particular room with given length and width.
thanks
Sufi
For lighting use DIALux.
yetunde
i need to get th latest software for the design of residential buildings in electrical. also i want to know how to calculate the numbers of fluorescent lamp for a particular room if given the length and width.
jay
just make use of the lumen method for calculation
jay
its very simple check out my blog at http://electservicedesign.blogspot.com/
md abrar mohiuddin siddiqi
i have a duplex house in which 8 bedroom are there. but i am confused how many electric board required in each bedroom. one electric board on the entrance and second board beside the bed. But tv come on another wall, so for tv also required electric board
ARSHAD AYUB RAZA TAUSEEFI
nice i got sufficient information
fredrick kanakulya
Two bedroom house with toilet small kitchen . Electrical drawing
KD
I am very happy and love to read this article. I am waiting for your next article too.
Amos Oduory
Its great and empowering, i like reading it regularly
Sunday Ojofu
Please don’`t stop, I am seriously waiting for your next article. I love this.
waheed yusuf
At least I have learn one or things about electrical.
waheed yusuf
I love to learn more from you .
nmr
PL ALSO PROVIDE A MAIN SWITH,MCBS ETC WITH RATINGS AND ACTUAL WIRING DIAGRAM OF PHASE,NEUTRAL AND EARTH WIRES FOR THE ABOVE 3 BED ROOM/HALL LONGUE ETC., THE WIRES RATING ALSO TO BE GIVEN// URGENT PLEASE
Sufi Shah Hamid Jalali
Dear Nmr. If you have any specific question in technical terms please email it to me directly so I can answer you in that case.
nmr
SIRS, IN INDIA WE ARE USING 5 A OR 15 A SOCKETS OR MULTIPLE SOCKETS TO USE 5 A APPRATUS AND 15 A APPARATUS IN THE SAME SOCKET// THE ABOVE INDICATES 13 A OUTLETS// FIRST OF ALL PL TELL ME OUTLET MEANS WHAT//
AND 5 A SOCKETS ALSO WE ARE USING MULTIPLE TYPE //TO SUIT TWO PIN LOADS AND TO USE 3 PIN LOADS// AS SUCH PL CLRIFY THE SAME.
THX
Ken
Outlet means the point from which your load/apparatus is connected to power. In this article Outlet=Socket
Sufi Shah Hamid Jalali
Don’t worry guys, I will continue to continue this topic and to post new ones through EEP. Thanks to Edvard as well for his assistance in publishing my articles.
ahmad al-qawasmeh
Thanx
FERDINAND CHIDUBEM
thanks to you alot for the teaching please am always inquisitive of things about electrical connection but will you help me to be doing it practically at anywhere i am and can even make me your worker after some training
muqtar
wow its great, and please post some good small projects like this regularly.
Amit Anand
I want to read this regularly..
Amit Anand
I excited to read this..