How to Quote Electrical Installation Work: A Step-by-Step Guide for Electrical Contractors

What you will learn

• How to run a pre-quote site survey that captures cable routes, containment paths, and specialist items before you touch your pricing.
• How to build a materials takeoff by category - cables, containment, accessories, and specialist items - so nothing gets missed.
• How to allocate labour by installation stage: first fix, second fix, testing and inspection, and commissioning as separate estimates.
• Why applying a 20% markup does not give you a 20% margin, and how to calculate the correct target price using the margin formula.
• How to write a quote document with explicit inclusions, exclusions, provisional allowances, and payment terms that protect you when scope changes.

Electrical installation quotes fail in predictable ways. A cable run turns out to be twice as long as the drawing suggested. A distribution board requires specialist busbar work that was priced as a standard install. Labour hours on second fix run 30% over because termination counts were done from incomplete drawings. By the time the job closes out, the margin that looked comfortable at quote stage has been cut in half - or wiped out entirely.

The core problem is rarely carelessness. It is a quoting process that lacks structure: no consistent survey checklist, materials priced from memory rather than a proper takeoff, and labour estimated as a single total rather than broken down by stage and role. This guide sets out a step-by-step process for quoting electrical installation work that builds in the rigour needed to protect your margins from survey through to quote submission.

Step 1 - Run a Structured Pre-Quote Survey

The survey is where most quoting errors are introduced. Visiting site without a fixed checklist produces inconsistent information, and incomplete information produces inaccurate quotes.

Before the visit, review any drawings or specifications sent by the customer or main contractor. Identify what is confirmed and what is unclear - document both. Where drawings are incomplete or show items without full specification (a luminaire schedule with no fitting references, containment shown without sizing), raise written requests for information (RFIs) before or during the survey rather than making assumptions.

On site, walk every cable route and record actual conditions: ceiling void access, floor-to-ceiling heights, structural obstructions, existing containment that can be reused, and any elements that require specialist access or out-of-hours working. Photograph anything that adds complexity - awkward penetrations, areas requiring fire stopping, surfaces that affect cable choice.

Capture the following explicitly, because each one has a direct cost implication that is easy to miss:

• Distances between distribution boards and sub-circuit endpoints (not scaled from drawing - walked or measured on site)
• Containment paths: surface-mounted trunking, skirting duct, cable tray, conduit, or concealed
• Number and type of distribution boards and consumer units
• Any specialist items: emergency lighting control gear, DALI dimming systems, three-phase equipment, generator connections, earthing and bonding requirements
• Location and route of main incoming supply and any metering requirements
• Certification requirements: does the scope require an Electrical Installation Certificate, a Minor Works Certificate, or a full EICR?

A 30-minute survey done properly produces a quote that holds up. A 15-minute site visit followed by desk-based guesses produces quotes that erode margin on every job.

Step 2 - Complete a Full Materials Takeoff

Once the survey is done, build your materials list from the ground up rather than estimating a round-figure total. Split materials into categories so you can price each section accurately and spot omissions more easily.

Cables: List by type and cross-section - 6242Y twin and earth (by size), SWA (armoured), FP200, data cabling, and any specialist cables - with quantities in metres. Add 10-15% for waste and route deviations. Cable is one of the highest-risk categories for cost overruns because site conditions often add metres that were not visible on the drawings.

Containment: Trunking, conduit, cable tray, and basket tray. Price by run length and factor in fittings: bends, tees, junctions, and end caps. These fittings add up quickly on complex routes and are routinely underestimated when priced as a fraction of the main containment cost.

Accessories and wiring devices: Sockets, switches, plates, grid fittings. Count from a drawing or schedule - never estimate by floor area. One wrongly sized faceplate or a switched versus unswitched confusion on a customer-specified product means a return visit.

Luminaires and specialist items: Source actual pricing for specified fittings rather than using budget figures. Emergency fitting types (self-contained versus central battery versus maintained) all have different unit costs. DALI drivers and dimming accessories carry a significant premium over standard gear. If luminaire selection has not been confirmed, exclude them from the quote explicitly and state what allowance you have included.

Distribution boards and consumer units: Confirm the number of ways, the incoming protection rating, and any metering or sub-metering requirements. A board with 18 ways is not the same cost as a 40-way board, and getting this wrong directly hits the quote.

Consumables and fixings: Add 5-8% of total materials for clips, saddles, draw wire, tape, glands, and site consumables. These items are rarely counted and regularly cause costs to exceed the materials allowance.

Step 3 - Calculate Labour by Stage

Labour estimation is where electrical quotes lose the most margin, because hours are underestimated and the breakdown between installation stages is treated as one number rather than four.

Split your labour estimate into four distinct stages:

First fix: Running and terminating cables, installing containment, fixing back boxes, and any rough-in work that happens before plastering or fit-out. This is typically the highest-hours stage. Benchmark from your own completed jobs, not from rule-of-thumb figures. A new ring main on a domestic extension is 6-8 hours first fix; the same scope in a suspended-ceiling commercial environment with steel trunking can be 15-20 hours for the same cable count.

Second fix: Fitting wiring devices, hanging luminaires, connecting accessories, and completing terminations at distribution boards. Time per point depends heavily on access conditions and ceiling height. Luminaire types with significant assembly time (panel-mounted downlights, track systems, external IP-rated fittings) take longer to install than surface-mounted pendants. Build your labour rate from the specific fitting types confirmed on the survey, not an average across the job.

Testing and inspection: IET 18th Edition wiring regulations require that all work is tested and certified. Allocate specific hours for testing rather than folding it into second fix. A 20-circuit consumer unit with a full EICR takes 3-4 hours for a competent operative; a larger commercial installation with multiple distribution boards may take a full day. Under-allocating test time is a consistent source of margin erosion.

Commissioning and handover: Any system requiring commissioning (DALI, emergency lighting systems, access control interfaces, AV or building management system interfaces) needs dedicated time that is separate from installation labour. Commissioning is often removed from the quote to sharpen the price and then absorbed as cost when the customer expects it to be included.

Apply a fully burdened hourly rate that includes the operative's base pay, employer's National Insurance, holiday pay, tool allowances, and a proportion of supervision cost. Using the bare operative rate without burden will make your quote look competitive while hiding a loss.

Step 4 - Sub-contractor and Specialist Allowances

Electrical installation scopes regularly include work that sits outside the main contractor's direct capabilities: fire alarm systems, structured data cabling, access control, or specialist containment fabrication. These elements need to be priced separately and tracked as distinct cost lines.

For each specialist sub-contract element, get written pricing rather than carrying a provisional allowance. A confirmed price from a specialist supplier is a commitment you can manage; a provisional sum is an estimate that can move in either direction.

When you receive a sub-contractor or specialist supplier quote, apply a management margin to cover your coordination cost, any warranty exposure, and site access management. A typical management margin for specialist sub-contract elements is 12-20% depending on the complexity of the interface. Carry this as a separate line on the quote rather than blending it into the overall price - if the customer queries it, you can explain and justify it.

Where you are sub-contracting to a supplier who is also providing materials as part of their package, confirm that their pricing is firm and not subject to material price variation after order. Get this in writing.

Step 5 - Recover Your Overhead

Overhead costs - office, vehicles, insurance, admin staff, estimating time, training, certification, tool replacement, and management - are a real cost of doing business. If they are not recovered in every quote, they erode the profitability of your entire portfolio, not just individual jobs.

Electrical contractors typically carry overhead at 13-20% of total sales (Housecall Pro, January 2026). To recover this in your pricing, calculate your overhead rate as a percentage of direct costs and apply it to each job. For example, if your annual overhead is £150,000 and your annual direct costs are £900,000, your overhead recovery rate is approximately 16.7% of direct costs.

Check this figure against your actual accounts at least quarterly. If revenue is down on plan, your overhead rate against actual costs is higher - and prices that looked safe at the start of the year may no longer cover overhead at current volume.

Step 6 - Apply Margin and Check the Final Price

With materials, labour, sub-contractor costs, and overhead recovery calculated, you can apply your target profit margin to arrive at a final price.

The most common pricing mistake in electrical contracting is confusing markup and margin. A 20% markup on direct costs produces a 16.7% margin (profit as a percentage of revenue), not a 20% margin. Specialty electrical subcontractors typically target gross margins of 26-34% (Drawer AI/Hubstaff, April 2026), which requires a markup of approximately 35-50% on direct costs depending on overhead rate.

Use margin, not markup, as your primary target. The formula is:

Target price = Total direct costs / (1 - target margin)

For a target gross margin of 25% on £40,000 of direct costs: £40,000 / (1 - 0.25) = £53,333. If you had applied a 25% markup on the same direct costs, you would have priced the job at £50,000 - £3,333 short of what your target actually requires.

Before finalising the price, sense-check it against your market rate for similar scope and against the customer's stated budget if they have shared one. A quote that is significantly above market suggests either that your costs are uncompetitive on materials (check supplier pricing) or that your labour allocation is higher than market rate (review benchmarks from recently completed comparable jobs). Do not reduce your margin to close the gap - identify and address the underlying cost issue, or accept that the job may not be the right fit.

Step 7 - Write a Quote That Protects You When Scope Changes

A price alone is not a quote. The document you send needs to define what you are pricing, what you are not pricing, and the conditions that apply.

Cover price and summary: State the total lump sum price and, where useful, a brief summary of what it covers (e.g. "first and second fix electrical installation to floors 1 and 2, including testing and certification, as per drawings ref. E-001 to E-004 rev B").

Schedule of works: Break the price down into sections - containment, cabling, accessories, distribution, testing, commissioning. You do not need to show your cost build, but a section breakdown makes it easier for the customer to compare against scope and for you to raise a variation order if scope changes in one section.

Inclusions: List specifically what is included. Do not assume that because it is in the drawings it is understood to be in your price.

Exclusions: This is the section that protects you. Explicitly exclude anything that was not confirmed at survey, anything that requires decisions from the customer that have not been made, and any work that would typically fall to another trade or the main contractor. Standard exclusions include: making good and patching after cable routes, structural penetrations, asbestos removal or management, specialist access equipment beyond standard step ladders, work in areas not accessible at time of survey.

Provisional allowances: Where you have included an allowance for an item not fully confirmed (a luminaire type pending customer selection, a data point count not yet finalised), state the allowance as a named line and note the conditions.

Validity period: A quote is a commercial commitment. Copper and other material prices move. State that the quote is valid for 30 days (or your preferred period) and that prices are subject to review if materials costs move materially between quote and order confirmation.

Payment terms: Include your standard payment terms. For larger commercial installs, this is typically stage payments linked to completion of defined milestones (for example: 25% on order, 25% on completion of first fix, 35% on completion of second fix, 15% on test certification). State these clearly - do not assume the customer will accept standard 30-day net terms on a six-week installation project.

Protecting Margins From Quote to Invoice

A well-structured quote is the beginning of margin protection, not the end. When the job is confirmed, the quote scope, the labour allocation, and the materials list need to translate directly into a works order, a purchase order to your supplier, and a delivery schedule that ensures materials arrive when needed. Misalignment between quote assumptions and operational execution is where contractors lose the margin that the quote was designed to protect.

Zigaflow connects the quote to the job: confirmed quotes convert into works orders with the scope attached, purchase orders are raised from the materials list, and stage invoices are issued as installation milestones are completed. When materials costs come in differently from the quote estimate, job cost visibility highlights the variance before it feeds through to the final invoice. For electrical contractors who want to stop losing margin between quote acceptance and job close-out, starting the process from a structured quote is the first step.