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Big interior design mistakes to avoid when planning a house extension

We've partnered with the interior design experts, My Bespoke Room, to bring you this guide to mistakes every homeowner

9 min read

Deciding to extend your home is never a decision to be taken lightly. The process can be stressful thanks to the immense number of decisions involved, the need for meticulous planning, as well as the constant pressure for perfection - all whilst trying to stay strictly within your budget!

If you’re considering extending your home, then we suggest asking yourself a few questions before taking the plunge to make sure you have thought of everything you need. Many decisions are made too late in the process and this can lead to expensive mistakes down the road, especially when it comes to decorating your new space.

We’ve asked the UK's #1 Rated Interior Design Professional, My Bespoke Room, to share their top tips for designing an extension, so that you can avoid making any expensive mistakes. An interior designer bridges the gap between your architect’s drawings and an interior space that functions perfectly and makes you happy every time you enter it.

If you want an expert second opinion on your plans, their consultancy package could be just what you need. The service starts from just £195 - find out how it works or book your free, no-obligation consultation.

What will you do with your new space?

My Bespoke Room - Ayesha Hakim Rahman

This used to be a very disjointed space but thanks to our incredible designer Jenny Branson, she was able to transform this room into an intimate, cosy and cohesive space for Ayesha and her family. Image credit: Ayesha Hakim Rahman

You should ask yourself this question before you can even start working out logistics, as it is a common problem. Many of us feel we need more space but don’t know what to do with it once the extension is complete. It’s vital to consider how you will make this space a functional part of your home. After all, what would be the point in extending your home to find the same lingering problems? That’s where we come in! A huge part of what we do is uncovering the problems you’re facing currently and creating innovative solutions.

However, we do encourage you to sit down with yourself and try to figure out what problems you are trying to solve with this new extension. Maybe you feel a little cramped at mealtimes or want more space for entertaining? Try to objectively watch how you and your family use the space over a few days and see where the frustrations lie.

Only once you know the problem can you begin planning the solution!

How can I create a seamless connection with the existing house?

The flow between your existing home and your new extension is vital when it comes to designing it. Of course, your new space can have its own personality and stand apart from the original building but we still need to create cohesion across your whole home.

The obvious solution that many people think is viable is to use the same paint throughout the whole home, however, this can look bland and flat. Think about giving the space its own personality. Perhaps you love pastel colours or even modern paint murals? As long as the colours you use have similar backgrounds or stories, you can use them in conjunction with each other to personify it and get creative!

However, the same can not be said for flooring. We suggest using the same, if not similar, flooring as your existing connected space, which will help tie together your existing home to your extension. Don’t forget to also include period features, like coving or skirting boards, into the new edition of your home so it doesn’t feel out of place.

How do you want to feel in the space?

Look and feel - mybespokeroom

Image credit: My Bespoke Room

When you’re applying for planning. sourcing contractors and working out strict budgets, it may seem trivial to think about how the room needs to “feel” but this is not something to be left as an afterthought. For the transformation to be a success, there are some decisions you need to make early on in the process, so you can achieve what you want to.

For example, bigger open-plan extensions aren't always “cosy”, but there are clever ways to warm up a large space and turn it into the heart of the home. The easy place to start is with wooden textures. It immediately adds warmth to a space. Think of a log cabin - you think cosy, right? Incorporating this texture instantly will make it feel more homely.

Lighting is another great way to bring warmth into a large open plan space. Many want to make sure they have enough light in the new space, but too much can leave the room being flooded with blinding, abrasive light. Instead, try to make it warm and intimate by bringing the lights to the level of the seating area, as this will make you feel cocooned within the space.

Don’t forget about the paint! You can trick the eye into making the space feel warmer by painting one or two walls in deep warm tones, differentiating that section.

How much natural light will you need?

Mybespokeroom - natural light

With large sliding doors this space will never be short of natural light! Image credit: My Bespoke Room

A great way to maximise natural light in your extension is by including big windows or bi-folding glass doors. However, this will take up a big chunk of your budget. Before you commit to these purchases, try to keep note of how light travels throughout the day in the space where your extension will sit. Where does the sun rise and set? For how long will the space enjoy spells of daylight?

Once you know where the light will be, then you can start making furniture arrangements, such as placing your TV. . You wouldn’t want to pop a TV where you’ll be battling against glare all day. Instead, think about popping a window seat where the light will be and create a snug reading/napping spot.

A great way to use the light innovatively is to think about windows above the sink in your new kitchen and work out if you could install a wide window that can be opened fully. Then you not only allow natural light and fresh air into a commonly stuffy place, but you could also include some outdoor bar stools and make yourself a summer bar! Perfect for entertaining outside without taking up any more patio space.

However, head our warning! There is such a thing as too much natural light, as the more glazing you have, the more you lose out on your privacy. No one wants to feel like they’re in a goldfish bowl in the evenings, where all your neighbours get front row seats to your comings and goings!

You can always implement window treatments like blinds or curtains but they can be tricky to get rid of and after all, what would be the point in spending all this money on natural light only to cover it up? It may be a good idea to opt for solar control glazing or coating to address this problem early on rather than trying to fix it later.

What should your lighting scheme be?

mybespokeroom - lighting scheme

Think early on where you'll need downlights for task lighting and lower level lamps for ambience. Image credit: My Bespoke Room

Never forget about your lighting scheme! If you do not take the time early on in the planning stage to think about where lighting needs to be installed, it will not only impact how it feels but how usable the space will be.

Trust us, you are not going to want to bring an electrician back in to punch holes in your beautifully painted ceiling or walls later on!

You are going to want different types of light depending on the space. For example, in your kitchen, you will want to be able to see what food you are preparing, so you will need brighter light than you would at the dining table. Conversely, when it comes to your dining area, you’ll probably want to include more ambience through dimmer and more soothing lighting, but still bright enough so that you can see what you are eating.

We suggest using different lighting circuits and always make them dimmable. That way you can create a more ambient feel easily and draw attention away from certain aspects of the room.

Last, but by no means least, don't forget about plug sockets! Make sure you have enough in the right places so you don't have unsightly wires trailing across your floor or across a wall. Especially in the world of smartphones, tablets and laptops where everyone wants a plug socket to hand!

Are you missing opportunities for storage?

mybespokeroom - storage

This hallway has a clever built-in seat so you can put on your shoes comfortably and has oodles of storage for every jacket and pair of shoes you could ever need! This is not only practical but also a unique focal point. Image credit: My Bespoke Room

Never forget about storage solutions or you’ll be kicking yourselves later! We all say once the extension is complete that we will be better, but old habits die hard and so keeping the new space chaos free, without putting in innovative storage, is unrealistic. After a few weeks, you’ll soon find the clutter creeping its way back in.

Don’t fight it, prepare for it! Make sure that the second you have your architect’s plans in hand, you dig out the best potential storage spaces, using every square inch of your new space. Too much storage is better than not enough!

Try to analyse your daily routine and think about how you’ll be using this room and therefore what will live in it? Are you likely to leave your post on the side? Maybe you need somewhere to put your keys? Create order out of chaos and organise yourself. Factor in shelves or draws in the space so you don’t end up popping something down for a moment and then never seeing it again.

Where will your furniture go?

mybespokeroom - furniture placement

The designer on this project persuaded the owner to move the radiator from the feature wall on the right which would have left little room for a sofa. My Bespoke Room

Do not leave furniture until the last minute! If you want your new space to function exactly how you need it to, you'll need to make sure you plan your furniture needs ahead of time.

We’ve already discussed bringing natural light in your home through bi-folding doors and large windows, but now you need to work out how your furniture will fit in when those doors are folded to one side. Is it practical to have a dining table in the blinding light? Would you prefer to have your sofa overlooking the garden, rather than a wall with nothing in it? These are the things you need to carefully consider while planning your extension.

You also need to consider your priorities. For example, if you have a large family you need to accommodate, you'll be needing an equally large dining table. Alternatively, you may instead opt for cleverly hidden seating that you can slide away when you need more space to move around during the day.

The easiest mistake to make is to not find a place to put your sofa due to a radiator being mounted on the only viable wall. Make sure you consider this in the earliest stages of planning, as it’s incredibly difficult to plan around once it’s been built!

To avoid expensive mistakes, consider working with an interior designer. Find out more about what these interior whizz-kids can offer by talking to the team at My Bespoke Room and exploring their packages. Book your free consultation here.

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