Growing Your Heating Business From One Van to a Team: The Financial Roadmap

Your diary is full. Your phone does not stop ringing. And you are quietly turning work away because there are only so many hours in a day.

Sound familiar? Then you are at the tipping point — the moment where staying as a one-man band starts holding you back rather than keeping things simple.

Growing a heating business from one van to a team is one of the biggest moves you will ever make. Get it right and you build something with real value. Get it wrong and you end up with more stress, more cost, and less money than before.

This guide is the financial roadmap. Real numbers, real costs, and a clear path from where you are now to where you want to be.

The Tipping Point: Signs You Have Outgrown Being a One-Man Band

Not everyone who is busy needs to grow. But there are clear signals that you have hit the ceiling.

You are turning work away regularly. Not the odd job — good, profitable work. Two or three boiler installs a month you cannot fit in. That is money walking out the door.

You are working 60+ hours a week. Early starts, late finishes, quoting on evenings and weekends. That is not a business — that is a trap.

Customers are waiting weeks for appointments. Three or four weeks? They will find someone else. And once they do, they rarely come back.

You cannot take a holiday without the phone ringing. If the whole operation stops when you stop, you do not own a business. You own a job.

If you are ticking three or four of those boxes, it is time to think seriously about your next step. But before you call a recruitment agency, there is something you need to look at first.

Before You Hire: Are You Actually Profitable Enough?

Here is the trap that catches a lot of trades businesses. Being busy and being profitable are not the same thing.

You might be turning over £80,000 or £90,000 a year as a sole trader. That sounds healthy. But if your costs are eating up £60,000-£70,000 of that, you are left with a wage — not a profit that can fund growth.

Consider this: taking on an employee means your business needs to generate enough extra revenue to cover their total cost, pay you at least what you earn now, and still leave profit on top. If the numbers are already tight, adding a wage bill will make things worse, not better.

Before anything else, you need to understand your numbers properly. If you have not nailed this down, our guide on managing cash flow in a trades business is a good place to start.

Understanding Your Numbers: What Your Profit Margin Needs to Be

As a rough benchmark, you want a net profit margin of at least 20% before you start hiring. That means for every £100 of revenue, at least £20 is genuine profit after all your costs.

Why 20%? Because your first employee is going to cost far more than their salary. And in the early months, before they are fully productive and building their own customer base, your margins will take a hit. You need that buffer.

If your margin is sitting at 10-15%, the priority is not hiring — it is fixing your pricing. You need to charge more, reduce your costs, or both. Have a read of our guide to pricing your plumbing and heating jobs properly before you take on any extra overhead.

The Real Cost of Your First Employee

This is where most people get a nasty surprise. You think, “I will pay someone £35,000 a year.” But the actual cost of putting that person in a van and sending them out to jobs is far, far higher.

Let’s break it down.

First Employee Cost Breakdown

Read that bottom line again. A £35,000 salary turns into a true cost of somewhere between £50,000 and £56,000 once you factor in everything it takes to get that person on the road and working.

And here is the key number: that employee needs to generate at least £70,000 or more in revenue to make the hire worthwhile. That covers their cost, contributes to your overheads, and leaves actual profit. If they are only bringing in enough to cover their own expenses, you have given yourself an extra headache for no financial gain.

Employment vs Subcontracting: Which Route Makes Sense?

You do not have to put someone on your payroll straight away. Subcontracting is another option, and it is worth understanding the difference before you commit.

Employing Someone Directly

Pros: You control quality, scheduling, and customer experience. They wear your brand. You build a team culture. Customers deal with your business, not a random subcontractor.

Cons: Higher upfront cost. Employer’s NI, pension, holiday pay, sick pay, and all the obligations that come with being an employer. You also take on employment law responsibilities — contracts, right to work checks, health and safety duties.

Using Subcontractors

Pros: Lower commitment. No employer’s NI or pension to pay. You can scale up and down with demand. Useful for overflow work or specialist jobs you do not normally handle.

Cons: Less control over quality and timekeeping. They are not “your” team. And HMRC takes a very close look at whether someone is genuinely self-employed or whether they should be on your payroll. Get this wrong and the tax bill lands on you.

If you go down the subcontractor route, you will almost certainly need to operate within the Construction Industry Scheme. That means making CIS deductions and filing returns with HMRC. Our guide to CIS for plumbing and heating businesses walks you through exactly how it works.

In my eyes, if you are serious about building a brand and growing long term, employment is the stronger route. Subcontracting is useful as a stepping stone or for handling peaks in demand, but a team of employees is what builds a business with real value.

Sole Trader vs Limited Company: Time to Revisit the Question

If you are still operating as a sole trader and you are thinking about taking on staff, it is time to have this conversation again.

As a sole trader, you are personally liable for everything. Every debt, every claim, every mistake your employee makes on a job — it all falls on you personally. Your house, your savings, the lot.

A limited company puts a legal barrier between you and the business. If something goes wrong, the company is liable, not you as an individual (assuming you have not been negligent or fraudulent).

Beyond liability, there are real tax advantages once your profits reach a certain level. A salary and dividends combination is typically more tax-efficient than drawing everything as sole trader profits. For more on getting the right structure in place, take a look at our guide to business structures for trades businesses.

Let’s be direct: if you are growing a heating business and planning to employ people, operating as a limited company is almost always the smarter move. The protection alone makes it worth it.

Systems You Need Before You Scale

Hiring someone before your systems are in place is like fitting a combi boiler without flushing the system first. It might work for a bit, but it will cause problems down the line.

Here is what you need sorted before your first employee starts.

Job management software. Something like ServiceM8, Tradify, or Fergus. You need to be able to schedule jobs, assign them to engineers, track progress, and invoice — all from your phone or laptop. If you are still running things from a paper diary, you are not ready to scale.

Proper bookkeeping. Xero or QuickBooks, set up correctly, with bank feeds connected. You need to see your numbers in real time, not find out three months later that you have been losing money.

A separate business bank account. If personal and business money are still mixed together, sort it out today.

A clear pricing structure. Your employee needs to know what to charge. Set prices for common jobs, a clear quoting process for larger work, and margins built in from the start. Have a look at our pricing guide if you have not locked this down yet.

Employment contracts and HR basics. A proper employment contract, a staff handbook, and an understanding of holiday, sick pay, and working time obligations. A good HR template can sort this for a few hundred pounds — do not skip it.

Funding Your Growth: Where Does the Money Come From?

You know the costs. You have the systems. Now, how do you actually pay for it all?

Reinvesting profits. The cleanest option. No debt, no interest. The downside is speed — you might need to save for six to twelve months before you are in a position to hire.

A business loan. High street banks and specialist lenders offer unsecured loans from £5,000 to £50,000+. You will need trading history, accounts, and a plan. Expect around 6-12% APR depending on your circumstances.

Asset finance for vans. Spread the cost over three to five years through hire purchase or a lease. This keeps cash in the business and the monthly payments are tax-deductible. Most van dealers can arrange this directly.

A business credit card or overdraft. Useful for short-term cash flow gaps but not a growth strategy. Keep these as a safety net.

In my eyes, the ideal approach is a mix. Save enough from profits to cover the first three months of your new employee’s costs, use asset finance for the van, and keep a small credit facility as a buffer.

The 3-Stage Growth Path

Growing a plumbing business does not happen in one leap. It happens in stages, and each stage changes your role in the business.

Stage 1: You + One Employee

You are still on the tools full time. Your employee handles their own jobs, but you are supervising and dealing with customers. Your day gets busier, not quieter.

The financial upside: business revenue should increase by 60-80% without doubling your overheads. The key is not trying to do everything. Get your admin under control and use your software properly.

Stage 2: You + Two or Three Engineers

This is where things change fundamentally. You start spending more time managing than fitting. Revenue could be hitting £250,000 – £400,000+ depending on your mix of work, but margins might dip as you pay more wages and generate less billable income yourself.

The temptation is to stay on the tools because it “feels” productive. Resist it. Your job now is to win work, manage quality, and keep the numbers healthy. Every hour you spend fitting a radiator is an hour you are not running the business.

Stage 3: Office Support, and You Run the Business

At this point, you bring in admin or office support — someone to answer the phone, book jobs, chase invoices, and handle the paperwork. You are no longer on the tools at all. You are the business owner.

This is where a scaling plumbing business starts to have real value. It can run without you being on site every day. It has systems, staff, and a reputation. If you ever want to sell it, this is what a buyer pays for.

Not everyone wants to get here, and that is fine. Some engineers are happiest at Stage 1 with great margins and a manageable workload. The point is to grow deliberately, not by accident.

When to Bring in a Specialist Accountant

A generic accountant who files your tax return once a year is not going to help you navigate this. Growing a heating business involves payroll, CIS, VAT thresholds, corporation tax planning, and cash flow forecasting. That is specialist territory.

You need an accountant who understands trades businesses. Someone who can model what your first hire will actually cost and help you structure things properly from day one. The right accountant does not just save you tax — they stop you making expensive mistakes. When you are investing £50,000+ in a new employee, getting the sums wrong is not an option.

Your Next Step

If you have read this far, you are serious about growth. That puts you ahead of most.

Your situation will look different to anyone else’s. What matters is that you make this decision based on real figures, not gut feeling.

Ready to grow but not sure if the numbers stack up? Let’s run through your financials together — free consultation.

And if you want to sharpen up how you quote and price your work before you take the leap, pick up a copy of The Quote Handbook on Amazon. It will change the way you think about every job you price. If you are ready to put proper systems in place for growth, The Systems Handbook lays out the frameworks — available in Kindle, Paperback, and Hardback, or grab the Hardcover edition here.