How Do I Price Plumbing Variations Properly?

Pricing plumbing variations correctly is crucial to ensuring you don’t lose money or overcharge and scare off clients. Variations happen frequently, whether due to design changes, unforeseen site conditions, or client requests. If you don’t price them right, they can eat into your profit—or worse, leave you covering costs out of pocket.

Here’s how to price plumbing variations accurately and fairly.

01What Are Plumbing Variations?

A variation is any work that is added, removed, or changed from the original plumbing contract. These changes can happen due to:

• Client requests – The builder or developer wants to upgrade or modify plumbing work.
• Design modifications – Engineering changes require re-routing or extra fixtures.
• Site conditions – Unexpected issues like hard rock excavation, existing service clashes, or access restrictions.
• Regulatory requirements – Compliance changes that weren’t in the original scope.

Example
The builder originally planned for a standard hot water system, but now they want a heat pump system. That’s a variation because it involves different materials, labour, and installation methods.

02How to Price Plumbing Variations Properly

1. Get Variation Requests in Writing

Never proceed with a variation based on a verbal agreement. Always ask the builder or client to confirm in writing via email, formal notice, or site instructions.

• This protects you from disputes later on.
• It ensures the builder acknowledges the cost impact before you do the work.
• Some builders try to delay variation approvals—don’t proceed without one!

• Key Tip: If the builder says, “Just do it, we’ll sort it out later,” reply with:
• “Can you confirm the variation request and approval in writing before we proceed?”.

2. Break Down Costs Clearly

When pricing a variation, break it into three key components:

• Materials – Additional pipes, valves, fittings, fixtures, or specialised equipment.
• Labour – Extra hours or trades required to complete the change.
• Plant & Equipment – Any additional machines, access equipment, or tools needed.

• Example: A variation for relocating a water main might require:
• Extra 10m of pipe
• Half a day’s labour for 2 plumbers.
• Hiring a mini-excavator

Always itemize these costs so the builder understands where the price comes from.

3. Apply the Right Margin & Overheads

Many plumbers forget to add overheads and margins to variations. If you only charge for materials and labour at cost, you’re not making a profit!

• Include your overheads – Insurance, admin time, vehicle costs, and business expenses.
• Add a fair profit margin – Typically 15–30% depending on job complexity.

Key Tip
Your variation pricing should match the profit margin in your original quote. If you priced the main job at a 20% margin, don’t do variations at 10%.

4. Factor in Delays & Disruptions

Variations often slow down other work, requiring extra project management, delays, and scheduling adjustments. If a variation:

• Causes downtime while waiting for new materials.
• Requires rework or demolition of already completed sections.
• Pushes your team into overtime or weekend work.

Charge for the time lost! Builders may not like it, but your time has value.

Example
If a variation means you need to send plumbers back later, charge a mobilization fee to cover the additional travel and setup time.

5. Include Access & Compliance Costs

Certain variations require specialised access equipment or additional compliance work.

• Elevated Work Platform (EWP) hire for high-rise variations.
• Traffic control if working near roads.
• Additional inspections or certifications for regulated installations.

Key Tip
Always check if a variation affects compliance. If extra documentation or sign-offs are needed, factor in those costs too.

6. Get Approval Before Doing the Work

Never start a variation without written approval. Builders often try to push variations onto subbies and dispute them later.

• Send a formal variation quote before proceeding.
• Get the builder to approve in writing (email, signed form, site instruction)
• If the builder won’t approve, don’t do the work.

Example
“Per our discussion, the variation to relocate the sewer stack will cost $4,500 + GST. Please confirm approval before we proceed.”

7. Track Variations & Keep Records

Keep a detailed record of every variation, including:

• The original request (email, drawing markups, verbal instruction)
• Photos before, during, and after the variation.
• Time logs showing extra labour.
• Material invoices and delivery receipts.

Key Tip
Some builders delay variation payments or dispute costs later. A proper paper trail ensures you get paid what you’re owed.

03Common Mistakes When Pricing Variations

Doing variations without approval – Builders may refuse to pay.
Underestimating costs – Missing key expenses leads to losses.
Forgetting to add margins – You need profit on variations too!
Skipping overheads – Admin time, travel, and setup all cost money.
Not tracking variations properly – Poor documentation = no payment.

04Final Thoughts

Pricing plumbing variations correctly protects your profit and ensures fair compensation for extra work. Always:

• Get written approval before proceeding.
• Break down material, labour, and equipment costs.
• Include overheads, margins, and delays.
• Account for compliance, access, and extra admin time.
• Keep proper records to avoid payment disputes.

Need help pricing plumbing variations accurately? SNZ Plumbing Estimating can provide detailed variation breakdowns to ensure you never lose money on extra work! Get in touch today.

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05Understand What Counts as a Variation

A plumbing variation is any work that deviates from the original scope agreed upon in the contract or quote. It can happen for several reasons, such as:

• Design changes – The client or builder alters the original plans.
• Unforeseen site conditions – Example: Hidden services or poor soil conditions requiring extra excavation.
• Compliance requirements – Additional work needed to meet regulations (e.g., adding fire hose reels)
• Client-requested extras – Extra fittings, fixtures, or pipe rerouting that weren’t in the original quote.

Tip: Always clarify the project scope before starting to reduce unnecessary variations.

06Identify Variations Early

The sooner you spot a variation, the easier it is to address. Some plumbers only realize extra work is needed after they’ve done it—which makes it harder to get approval and payment.

• Study drawings carefully before pricing a job.
• Review specifications and notes (especially in commercial and healthcare projects)
• Inspect the site thoroughly before starting work.
• Communicate regularly with the builder and client about potential changes.

Tip: If you notice possible variations during estimation, flag them in your quote as "potential additional costs."

07Get Written Approval Before Doing Extra Work

Never proceed with variation work without written approval. If you do, you risk not getting paid for it.

Follow this simple variation approval process:

• Identify the variation and document what has changed.
• Estimate the extra cost (labour, materials, and any delays)
• Submit a variation request in writing (email is fine, but some contracts require formal forms)
• Wait for written approval before proceeding.

Tip If a builder or client asks for a verbal go-ahead, follow up with an email confirming the change and cost.

08Price Variations Fairly and Transparently

Nothing frustrates clients more than unexpected or overpriced variations. Be fair and provide a clear breakdown of your pricing.

Your variation price should include:

• Labour – Extra time required for the work.
• Materials – Additional pipes, fittings, fixtures, etc.
• Plant & Equipment – If special tools or machines are needed (e.g., core drilling)
• Subcontractors – If another trade is involved (e.g., concrete cutting)
• Extra Overheads – Admin time, supervision, or permits.
• Profit Margin – Don’t forget to add a reasonable margin!

Tip: Keep your pricing consistent with your original rates to avoid disputes.

09Keep Detailed Records

If a variation dispute arises, having proper records protects you.

• Emails & Approvals – Keep all written approvals.
• Photos & Site Reports – Before-and-after images help prove your case.
• Timesheets – Log extra labour hours for the variation work.
• Invoices & Receipts – Document any additional material purchases.

Tip: If a client disputes a variation, refer to your records to show that the work was necessary and approved.

10Communicate Openly to Avoid Disputes

Clear and professional communication prevents most disputes.

• Be upfront about variations as soon as they arise.
• Use simple, direct language when explaining extra costs.
• Keep the builder/client informed throughout the project.
• Don’t wait until the final invoice—get approvals as you go.

Tip: If a dispute does happen, stay calm and professional. Providing clear documentation will help resolve it quickly.

More on clients, builders and getting paid

11Related reading

• What Do I Do If the Builder Rejects My Variation Claim?
• How Do I Handle Clients Who Keep Asking for Free Extras?
• How Do I Avoid Bad Clients Who Don’t Want to Pay?
• How Do I Handle Builders Who Delay Payments for Months?

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