New Home Domestic Electrical Wiring Advice

March 3, 2016|Posted in: Domestic

We get a high volume of calls regarding electrical wiring in new builds and some of the calls are just for advise – which we are happy to help with.

Your electricians / contractors have a minimum of the  following documentation:

  • Public Liability Insurance – a minimum of 2 million pounds.
  • Employers Liability Insurance – Larger companies with employees  (usually 10 million pounds or more depending on number of employees).
  • Accredited by a government endorsed body – NICEIC, ELECSA, NAPIT, ETC (this means their work will be subject to annual review to insure that standards are kept high, and they can self notify your works to the correct building control body.
  • Health and Safety Policy.
  • Risk Assessments for all Projects.

Do not be shy to ask for copies,  it is your right as a consumer!


Electrical Design:

Often (far too often!), a property has no correct electrical design,  the issue here is that the consumer (YOU) thinks that an architects electrical layout is an electrical design.

NO NO NO NO NO NO (did we say no).

These are no more than simple position / location designs,  a true electrical design is usually for the electrician that is installing the fixed wiring and critical as it will detail the following (to name a few).

  • Cable Resistance Calculations (predictions).
  • Cable Containment and Routes (how the cable is to be installed – clipped direct, inside walls, through joists, etc).
  • Protective Devices and Ratings (Your Consumer Unit Devices (fuse board))
  • Cable Lengths and Sizes depending on your load (equipment you want to use – washing machines, heaters, underfloor heating).
  • Property External Loop Impedance.
  • Maximum Demand (calculated on your equipment installed – lighting, small power items).
  • Solar power (if needed).
  • Volt Drop (one of the most important areas – lights flicker,  equipment will fail, cables will degrade).
  • Fire alarm and Early Warning Systems – BS5839-2013 Electricians should be working to these standards.
  • Segregation of band 1 and band 2 cabling (keeping data away from mains wiring).

Can you see that the electrical design is a critical piece of information for your project!

When you receive the all important Electrical Installation Certificate at the end of your project it should contain 3 signatures.

  • The Designers Signature – should be the person that did the above design  (usually not the electrician!).
  • The Installers – the electricians that did the work on site.
  • The Test and Inspectors – sometimes the electrician sometimes a dedicated electrician familiar with testing and inspecting.


What to look for in your Electrician?

Professional and able to work to instructions,  a good solid understanding of the 17th edition BS7671 Amendment 3 (2015) ,  qualified (usually city and guilds) ask to see a copy of their qualifications.

Electricians at a minimum will have a 17th edition (city and guilds 2382),  they may also hold City and Guilds 2394 and 2395 (Initial verification and testing and inspecting respectively) and / or other previous qualifications that will give them a good grounding of electrical installations.

Electricians should be like anyone, polite, friendly, approachable and able to detail the work they are doing when required.

A good electrician will have a copy of the Onsite Guide (this is a smaller more manageable version of the 17th edition BS7671 2015) a must for electricians when working on site.


Quality of electrical work you should be looking for:

From the design we mentioned earlier:

Cables clipped, Containment Systems Installed and supported correctly.

Pride in their work,  and the ability to follow the design drawings.







We will update this page with new advice from time to time.

Good luck and follow the simple steps and you will have a perfect installation that will last for years to come.  If you need any help or would like a free no obligation estimate do not hesitate to call us!

020 7281 2656