Architect fees depend on the firm you use and the complexity of your home extension project, but in general, you can expect to pay significantly more to use an architect for your extension than if you used a design and build company. Here’s how much an architect will cost and whether or not you need to use an architect at all.

How Much Does an Architect Cost for a House Extension?

In general, you can expect architecture fees to be 5-10% of the cost of your house extension. So, if your overall project is expected to cost £80,000, you should add an additional £4,000-8,000 for your architect. This is a significant fee that takes money away from your renovation and refurnishing your space, so it’s highly recommended that you get several quotes from different architects or use this cost calculator from our design and build company in London to get a clear idea of how much your extension will cost. 

The Different Ways in Which Architects Charge for their Work

Again, this varies depending on the firm you employ. Generally, an architect will charge you one of four ways:

  • Percentage of the project – This is a common charging method and, as we mentioned above, it will be 5-10% of the total project cost. As a result, it is very important to have a clear idea of how much your extension should cost to build this into your budget.
  • Fixed fee – Some architects charge a fixed fee, so no matter how much or how small your project costs, their fee stays the same. They will determine this fee based on how much work they think they will need to put into your project. The fee will be higher if you want them to take on additional roles in the project, such as project management.
  • Hourly fee – This is the way a lot of other professional services operate. For architects in the UK, you can expect to pay £50-90 per hour. In this fee system, it’s important to understand how many hours they expect to work on your project, especially if you need them to draw up different plans or project manage the extension. However, this is difficult to estimate because if it turns out to need more hours than the architect originally projected, your fees are going to be higher.
  • Mixed fee structure – This is a combination of fixed and hourly fees, where some services have a fixed rate and others don’t. For example, they may have a fixed fee of £300-500 for a site survey and an hourly fee for drawing up your plans.

What’s Included in an Architect’s Fees

Generally, the architect’s fee covers:

  • Up-to-date drawings of your existing house plan
  • Architectural drawings of the extension
  • Technical drawings for building regulations and construction
  • A planning package

Additionally, they may be able to offer you:

  • Sourcing of contractors
  • Project management services
  • Contract administration
  • Feasibility studies
  • Planning permission and permit applications
  • Historic preservation research

What Can Affect Architect’s Fees?

One of the biggest influences on an architect’s fees is the project itself, after all, a massive extension to a listed home in the heart of London is going to be very different in planning and execution than a small kitchen extension in a suburban home. Here are the main factors influencing the cost of having an architect:

  • Prestige – A very well-known, award-winning firm in London will charge you higher fees than a small, relatively unknown firm.
  • Location – For example, London is much more expensive than other cities or even outlying towns, so your postcode plays a big role in determining architect costs.
  • Size/scope – Architect fees for small extensions are naturally lower than for larger ones.
  • Complexity – A more straightforward extension will cost you less in architect fees than one that is more difficult, for example, if access is very difficult, it’s a listed building, if you need excavation, or if you are dramatically changing your home.

Do I Need an Architect for an Extension?

For most extensions, you don’t need an architect at all. It’s not even a legal requirement to hire an architect or get architect drawings in the UK for projects of any size. But unless you have a lot of building experience yourself, it’s good to have professionals assist you with designing and building your extension, even if it’s a small extension.

Hiring an architect can be very expensive and not always worth it if you have a look at the alternatives, which include a design and build company. Of course, it’s best to use a company that has a good track record and a team of design and construction specialists to make sure your extension is elegant, fits your lifestyle, and lasts a lifetime.

Read more about building regulations in the UK.

Using a Design and Build Company for Your Extension

If you want the same quality and design focus as an architect-driven build combined with greater affordability and a faster timeline to completion, it’s time to give the Plus Rooms team a call. We are an experienced, full-service design and construction business in London, handling every aspect of your construction project from start to finish – quickly, cleanly, and ensuring the highest quality design and build results at every step.

You can use our cost calculator to get a clear idea of how much your home extension will cost and where those costs lie.

We have an exceptional track record of completing over 1,400 projects in homes throughout London to world-class standards. In addition to handling small home extensions and kitchen extensions, we also specialise in single storey, double storey, and loft extensions. Contact us today or visit our gallery to see how our talented and experienced design and build company delivers exceptional results – for less.