Do You Need a Quantity Surveyor for your home extension?
If you’re planning a home extension, whether it’s a new kitchen-diner, loft conversion, or a larger living room, you may have heard the term quantity surveyor thrown around. But what exactly do they do, and do you really need one for your project?
So, in today’s post, we’re going to break it down.
What Does a Quantity Surveyor Do?
A quantity surveyor or QS is a construction cost consultant. Their role is to manage and control costs from the initial budget right through to final account. They help clients get value for money, reduce financial risk, and keep projects within budget.
Their services can include:
- Producing cost estimates and feasibility studies
- Preparing tender documentation
- Assessing contractor quotes
- Monitoring ongoing project costs
- Managing variations and payments
- Advising on contracts (like JCT or NEC)
So, should you hire one for an extension?
When You Should Consider a QS for an Extension
You probably don’t need a QS if you’re just building a small conservatory or updating a bathroom. But if your extension is more substantial, say over £30,000 in construction costs, there are good reasons to bring a QS on board. This can include
1. You Have a Strict Budget
If you need to stick to a specific figure, a QS will help break down costs, identify savings, and avoid surprises.
2. There Are Multiple Trades Involved
The more complex the build (e.g. involving structural changes, electrics, plumbing, or steelwork), the more value a QS can add by coordinating and pricing everything correctly.
3. You’re Managing the Project Yourself
If you’re not using a main contractor and plan to manage individual trades, a QS can help prepare detailed schedules and check contractor pricing for fairness and accuracy.
4. You Want to Avoid Disputes
QSs help draft and manage formal contracts, reducing the risk of disputes over payments, delays, or quality.
When You Might Not Need a QS
- Simple projects: Small single-storey extensions with one contractor often don’t justify the cost of a QS.
- Design & build packages: Some builders offer turnkey services that include cost control, although it’s still worth checking if their pricing is transparent.
What Will It Cost?
Hiring a quantity surveyor for an extension isn’t always a major financial commitment, especially when you consider what they’re there to do: stop you from overspending.
The cost of QS services varies depending on the size and complexity of your project, how involved you want them to be, and whether they’re working on a one-off basis or across the whole build. Some homeowners bring a QS in just to sense-check a contractor’s quote, others prefer a hands-on service throughout the job. Both approaches are valid and both can be tailored to suit your budget.
And don’t worry, this isn’t only a service for high-end, luxury builds. At Metroun, for example, we regularly work with homeowners doing sensible, everyday extensions who just want to feel more in control of their costs. Often, it’s about striking the right balance: enough input to keep things on track, without paying for support you don’t need.
Final Thoughts
Hiring a quantity surveyor isn’t always essential for a house extension, but for medium to large-scale projects, their expertise can bring clarity, cost control, and peace of mind.
If you’re unsure, speaking with a professional like us at Metroun is a smart first step. One call could save you thousands of pounds.
