How To Plan And Build The Perfect Kitchen Extension

Everything you need to know about creating a luxurious glazed kitchen space for your home.


06 Sep 2019


Simon McAuliffe

Hunters Lodge

A glass extension is one of the most impactful and effective changes you can make to your home. From simple, minimal glass doors, to elaborate frameless glass boxes, a house extension floods a space with light, but how do you actually go about getting one installed?

Many of our clients come to us with only a very simple concept in mind, and that’s absolutely fine – but if you want to get down to the planning process yourself, there are few crucial things to be aware of. From budgets to planning permissions, here’s how to plan and build the perfect glass extension for your home.

Where to start?


Often, with a large project such as a kitchen extension, it can be hard to know where to begin. This hurdle is often the largest, but once you’ve got your head around things the process can actually be fairly straightforward (particularly with the right specialists on board, but we’ll get to that!)

While it can be tempting to start drawing up budgets and schematics, there are a few things you should think about early on, to make the process more manageable:

Start with a concept


Many homeowners will already have a concept in mind for their extension, but if you don’t have a firm idea in mind, this is the place to start. Ask yourself, what are you hoping to add with your kitchen extension? What kind of space, both practically and aesthetically, are you looking for? At the earliest stages of planning, this should be a simple, broad concept, such as ‘I’d like to have more surfaces to work on’ or ‘I’d like a kitchen with more natural light’.

Come up with some general design ideas


With your overall concept and goals in mind, the next step is to come up with some general design ideas. This will mean considering your kitchen as it currently stands

This will include features you’d like as a part of your extension, such as the types of windows, things like glass roofs, and interior features you’d like to make room for. This will help inform your brief when you eventually present it to an architect.

How to plan a kitchen extension


Kitchen extension

So, you’ve decided to take the plunge, and that you want to plan and build your extension. You have a concept in mind, and you’ve thought about how you want your new space to look, feel, and things like the features you want to include. Now it’s time to get planning properly.



When properly preparing your plans, you’ll need to think about some practical implications. Firstly, consider size carefully. While it can be tempting to opt for the biggest square meterage your budget will allow, this isn’t always the best plan. In fact, there are times when this can cause issues further down the line.

How big does a kitchen extension need to be?


Think about how much space you really need, and work to that as a rough guideline. Think about the number of people using your kitchen at once as a guideline – do you need additional space, or is a continuation of the current layout plenty of room? An extension that’s too small is impractical and a waste of money – too large, and it could become unmanageable, or contrast badly with the rest of your home.


You’ll also need to have a clear idea in your mind of where in your home the extension will go with regard to your existing property. Naturally, many kitchen extensions will connect to the existing kitchen spaces in a property, but there are occasions when the extension will form an entirely new kitchen space that will stand alone.

Depending on the type, size, and shape of your home, some extension designs will suit better than others. Consider if you’d like your kitchen extension to connect to the rear or side of your property, or whether ‘wrapping’ it around an exterior corner would work. It can be a good idea to come up with a couple of ideas, in case structural or practical problems become apparent that you hadn’t considered.

Finding an architect

Once you’re confident you know what you want, and you know roughly how much you have to spend, it’s time to bring in the professionals. Specifically, you’ll need to consult with an architect to have plans drawn up and your kitchen extension project managed smoothly. Choosing an architect can be a bit daunting, but it really doesn’t need to be.

Do plenty of research, put together a shortlist, and don’t feel pressured to go with any one option. Ask to see examples of their previous projects (specifically, the ones that are very similar to yours), and if possible try to speak to some of their previous clients to find out how they were to work with. For more detailed advice, we’ve written a post on finding and choosing an architect – have a read!

Some useful places you can look include:

  • Royal Institution of Chartered Surveyors (RICS)
  • Chartered Institute of Architectural Technologists (CIAT)
  • Association of Building Engineers (ABE)
  • Chartered Institute of Building (IOB)
  • Institution of Structural Engineers (ISE)
  • Royal Institute of British Architects (RIBA)


Choosing a builder

With an architect for your project, you’ll need to employ the services of a building contractor – a role which is equally as important. Most architects will have worked with enough contractors to be able to recommend and excellent option for your specific project, but feel free to shop around as well. We would advise listening to your architect though, they know what they’re talking about!


Kitchen Extension FAQs


With all of these initial planning considerations taken into account, and the relevant specialists on board, you’ve ticked most of the tricky boxes when it comes to planning a kitchen extension. Most of the project management will be handled by your architect, and throughout the process, they’ll go through every step with you in detail.

Of course, there are still plenty of questions you may still have, and we’ll aim to answer as many as we can below:

Will a kitchen extension add value to my home?


It’s safe to say that in almost every case, adding more space to a property will increase value. Whether or not this increase offers a return on investment for how much you spend will naturally depend entirely on your budgets, and the specifics of both your project and your home – but broadly speaking, extensions often do add value overall.

In order to determine the likelihood of this, you’ll need to compare the total cost of the extension (which can be confirmed with your architect) with the potential increase in value to your home. You can use a tool such as this one to check what this could be.

Will I need planning permission for a kitchen extension?


Whether or not you need planning permission to build a kitchen extension depends on whether your project falls into the realm of ‘permitted development’. There are a number of criteria you’ll need to meet in order to determine this, such as no extension being higher than the highest part of the roof, and you can review the full list of specifications here.

There are a couple of other considerations to be aware of – proposals for extensions will still be subject to the associated neighbour consultation scheme. This means you’ll still need to inform the relevant Local Planning Authority of your proposed work by submitting a prior approval application.

Can I build a kitchen extension on a listed building?

The short answer is yes, although there are restrictions in place on altering listed buildings that you’ll need to be aware of. The extent to which these apply depends on whether your property is grade I or II listed, but you’ll need to contact your local planning authority to go through the specifics for your own home.

In general, it’s much harder to make changes to a grade I listed building, but grade II buildings will often be approved for alteration provided the extension doesn’t impact the original quality of the project. This is why glass extensions are such a popular choice for homeowners looking to increase their kitchen and living spaces in listed properties.

Take a look at another one of our blog posts for more information on glass extensions for listed buildings.

What insurance do I need for a kitchen extension?


Some home insurance providers will exclude loss or damage cover during the period a home is under renovation, so you may need to arrange some appropriate cover for the duration of the work. If your architect or contractor is overseeing the project, they may sort this out for you, but if you’re overseeing the project, you may need to organise it for yourself.

In this case, you’ll need to organise relevant site insurance, which will cover both the existing property and the new extension as it’s being constructed. Some providers even offer specific extension insurance.

Is there appropriate access to the property?


You’ll need to ensure there is plenty of safe access for the various vehicles and contractors working on your extension. This can involve delivery of construction materials, so you’ll need to think about how accessible your property is for this – a site survey or property visit is a very good idea, so speak to both your architect and contractor about attending the property to assess how best to approach deliveries and access.

What are the building regulations for a kitchen extension?


While many extensions will fall under permitted development, and therefore will not need specific planning permission, any kitchen extension you plan to build will still need to meet the usual building regulations.

The plans for your project will need to be approved under the Building Regulations 2010, and while your architect will usually be able to oversee this (and will only draft plans that meet these standards), there are a few areas that this will apply to specifically, so it’s important to understand the implications. These elements include:

  • Doors and windows
  • Drainage
  • Electrics
  • External walls
  • Kitchens and Bathrooms
  • Internal walls
  • Roofing


Will I need to move out during a kitchen extension?


Discounting the planning, consultation, and design phases of the project, it can take anywhere from 3 to 6 months (or sometimes even more) to construct an extension. Whether or not you move out during your kitchen extension will depend on preference, and the context of your home specifically.

Usually it’s possible to remain in the property, but you’ll need to consider the practical implications. If your existing kitchen is being removed, you’ll need to establish a new place to cook and prepare food in the interim. You’ll also need to consult your builder about the impact the build could potentially have, and figure out how to effectively protect your home from things like dust.