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Do I need an architect for my extension or home project?

Building an extension will give you extra living space and is a superb way of adding value to your home. You might want a bigger kitchen, a loft converted into an extra bedroom and an en-suite bathroom, or maybe to open up the back of your terraced home into an airy, sun-lit open-plan area.

But before you start knocking through walls, you might want to seek professional help first. Not only will this give you peace-of-mind (warning: attempting extensions on your own is risky and stressful), but it can also help you make the most of your investment, saving you time and money. At a time when the supply chain crisis is resulting in soaring costs for materials and labour, this could be crucial. 

In this video testimonial Nimi Attanayake of Nimtim Architects explains how an architect can help with a brief for your project.

It is possible to work directly with a good builder, presenting your ideas to them and toggling between various government websites to read up on the regulations to understand what permissions you need. However, it makes much more sense to secure the help of an architect, as we explain below:


Benefits of hiring an architect for an extension / Why hire an architect for your extension project

  • Planning permission If you live in a listed building or conservation area, you will need consent from the local authorities, as well as approval that the extension complies with building regulations covering foundations, damp proofing, heating and ventilation, fire safety, as well as the overall stability of the building. There are also planning rules about the extension size and materials used. All of which are in place to improve quality. An architect has technical knowledge and expertise to know what is required and will prepare and submit a planning application on your behalf and ensure the project meets building regulations.
  • To save costs The recent rise in construction costs means building an extension could be more expensive than you expect. An architect will help you manage your budget and prevent costs from spiralling. They may also be able to pass on trade discounts to you too. An architect will also give you a good idea of how much you will need to spend from an early stage. 
  • Architects’ professional expertise Good design will maximise the amount of storage available, the most natural flow of space, or the best use of natural light. An architect will ensure your extension fully reflects your personality and character. As architect Nimi Attanayake explains in the video, “we try to empower our clients to make bold choices they might not otherwise make.” 
  • Hiring tradespeople Your architect should have a tried and tested list of reputable contractors who specialise in different types of project (they can also help negotiate a fair price with the builders too). They can also refer you to other professionals, such as a structural engineer, where necessary.

Building an extension checklist 

  • Calculate a realistic budget for your extension, including the architect’s fee. To get a rough idea of costs, speak with a few architects first. 
  • Determine an approximate timeline. Assuming all goes well, how long will the project take? Depending on the level of construction, you may need to move your family out for a short period of time.
  • Find out whether you need planning permission. Many modest house extensions don’t need planning permission, but an architect can advise you. 
  • Let the neighbours know well in advance! Construction work may be noisy and a skip on the street outside may be an inconvenience, so it’s a good idea to keep them informed. If you share a wall with an adjoining property (or excavations within three or six metres of a neighbouring property) you may also need a party wall agreement. You must serve formal notice of this to your neighbours at least two months before work begins. Again, your architect can provide guidance on this.
  • Check your house insurance for cover during construction. Also, any construction work that changes the value or structure of your home may affect building and contents insurance, so ask your insurers to advise on that too.
  • Contact an architect as early as possible (see section below), asking them about their fees and an estimation of construction cost and how long the project may take. Talk to a few architects and ask to see examples of previous work.

You can find the right architect for your project by:

  • Using the RIBA Find an Architect service, which lists over 4000 RIBA-accredited Chartered Practices.
  • Contact the RIBA Client Referrals Service, and we will create a shortlist of practices in your area that have the relevant experience for your project.
  • Personal recommendation— but check that the architects are registered with the Architects Registration Board, and ask to see examples of their previous work, before you proceed.
  • Not sure if an architect is right for your project? Check our Why work with an architect? page on or get in touch with the RIBA Client Services team or 0207 307 3700.


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