Building extensions come in many shapes and sizes and costs vary enormously but when the project is well designed and managed, an extension can make a big difference to your living space and save the need for costly relocations.

You may know people who have designed and built their own home extension, or got their builder to do the design work, saving the cost of an architect. The straightforward answer to the question ‘Do I need an architect for a simple building extension’ is no – there are alternatives that might work for you. But when making this decision, it’s very important that you consider more than cost and weigh up the value an architect will bring in terms of skill, experience and knowhow.

Many a DIY project has spiralled way over budget for the want of a sound plan and strong project management. So let’s evaluate the benefits of hiring an architect to get your dream extension off the ground.

building extension

The magic

Good design is hard to define – you just know it when you see it. And while you might want nothing more than a simple box added to the back of your house, an architect will have the skill to design that box, both internally and externally, for genuine aesthetic and functional satisfaction.

They will take into account how you intend to use the space, what it needs in terms of utilities, heating and light, how it blends in with the rest of the house and garden, access and any other features that need to work within the overall design.

In addition to the inspiration they bring to the design, an architect will be able to bring the plans to life with 3D CAD renderings, making it much easier for you to visualise the finished extension and make any changes before any ground is broken. And a proper architect’s plan will enable you to obtain precise, like-for-like quotes from builders and make sure they stick to the plan throughout the project. This can save costly delays and disputes.


An architect who regularly works on extensions will have a wealth of experience of the potential pitfalls and key considerations involved. They will be able to give you accurate estimates of how long the project is likely to take, including the preliminaries like obtaining planning permission and building regulations; they will be able to advise you where you can save money and where it’s worth spending a bit more.

Their knowledge of the latest building materials will enable them to specify items you or your builder might not know about, eg items that add interest or functionality or save money. And they will be attuned to spotting potential snags well in advance, such as acoustic and fire regulations and party wall issues, which could otherwise force an expensive change of direction during the build if not identified in time.


Hold-ups to extension projects are often due to process disputes, such as planning permission, building regs, party wall agreements and building contracts. Architects are well versed in all these processes and will be able to advise you of your responsibilities. They can help you to speed up the process too; for example, by drawing up plans that they know will comply with local planning requirements.

The local knowledge of a local architect can be invaluable. They will be aware of the issues that tend to arise with similar projects in your area and their familiarity with local contractors will be helpful in selecting the best builder for the job at the best price.

If you feel uneasy about leaving the project management to your builder, or managing it yourself, your architect will be able to manage the project on site too. This third party buffer between you and your builder can help to allay misunderstandings and disputes, as well as keeping the project running on time and on budget.

On the face of it, hiring an architect for a simple extension can look like an unnecessary additional cost. However, when you weigh up the benefits an architect brings to any construction project – and count the cost of all the things that can go wrong if you go ahead without one – the argument for involving an architect goes way beyond the scale of the build. In addition to the peace of mind, punctuality and cost-efficiency benefits, you will end up with an extension that looks fantastic and gives you joy every time you look at it, inside or out.

Start your project off on the right foot. Talk to Greenway Associates today on 01737 652737.