Electrical design and electrical contracting: how the process works and what a quote should include

Short answer: An electrical design is the plan of a building's electrical installation (circuits, distribution boards, socket and lighting points, earthing, low-voltage systems) drawn by an electrical engineer. Electrical contracting is carrying out that design on site, with materials and labour. A good process starts before the foundations are poured: foundation earthing goes in before the concrete, conduit with the shell, cabling after plastering, switches, sockets and fixtures with the finishing work, and the job is handed over after measurements and tests. The quote should list materials, brands and the scope of labour item by item, based on the design.

What is an electrical design and who prepares it?

In Turkey the electrical installation design is part of the building permit process and is prepared by an electrical engineer. It usually includes:

• Lighting, socket and special appliance points on the floor plans
• Board locations and board schematics (breakers, RCDs, surge protection)
• Cable sizes and load calculations
• Earthing and, where required, lightning protection
• Low-voltage systems: data, TV/satellite, intercom, fire detection and similar

Connecting the building to the grid requires a separate application to the distribution company and meter arrangements. Wishes such as a smart home, EV charger infrastructure or cove lighting should be raised at design stage so they are drawn in and do not require chasing walls later.

What does electrical contracting cover?

The contractor carries out the design on site. The scope should be written clearly in the quote; typical items:

• Foundation earthing and earth measurement
• Conduit, junction boxes and back boxes in walls, floors and ceilings
• Cabling and installation/connection of distribution boards
• Low-voltage infrastructure (data, TV, intercom)
• Fitting switches, sockets, fixtures, downlights and sensors
• Cove, cabinet and garden lighting
• EV charger circuit
• Measurement, testing and handover

Step by step

1. Design and requirements: the design is prepared; wishes such as smart home, lighting scenes and EV charging are defined.
2. Site survey and quote: the contractor surveys the design and site and gives a written quote covering materials and labour.
3. Contract and programme: scope, material brands, payment plan and stages aligned with the construction schedule are agreed.
4. Foundations: foundation earthing is installed before the foundation concrete is poured.
5. Shell construction: conduit in walls, floors and ceilings; junction and back boxes; positions for cove lighting and drivers.
6. After plastering: cables are pulled and boards are mounted.
7. Finishing: switches, sockets, fixtures and system devices are fitted and board connections completed.
8. Testing and handover: earth and insulation measurements, RCD tests, and every circuit and system put into operation.

What a written quote should include

• An item-by-item material list based on the design, with brand and series (cable, breakers, RCDs, switch and socket range)
• Scope of labour and what is excluded (plaster repair, painting, demolition, the fixtures themselves, etc.)
• A payment plan by stage
• Duration and dependence on the construction schedule
• How changes (extra points, extra circuits) are priced
• The documents to be handed over

Quotes priced only per square metre leave the scope vague and often end up different.

What to ask for at handover

• The earth measurement result
• Confirmation that the RCDs have been tested
• Board labels showing which breaker feeds which circuit
• Updated as-built drawings where the work differs from the design

When to start

The best time is before the foundations are laid. Foundation earthing added later is harder and more expensive, and systems such as smart home and lighting control need to be planned at the conduit stage.

Electrical contracting with ENGN in Bursa

In Bursa, Turkey, we take on the electrical installation of villas, detached houses, apartments, residential complexes and offices from the foundations to handover. We do not draw designs; we carry out the design prepared by your engineer on site, survey it and give a written quote covering materials and labour. You can request a quote using the form on our electrical contractor page.

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• → Earthing explained
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• → Smart home wiring in a new build
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