10 common errors to avoid when building your house extension!

Errors to avoid when building your house extension


Having completed over 400 house extension projects in Newcastle and the North East, The Team @ Acre Design have seen it all! If you need extra space (bedroom/s, living space or that luxury kitchen, diner and lounge, for example) how can you avoid some common stressful and costly errors?

Seeking out advice from a local architect and doing your research is essential. This is why we’ve put together a list to get you started. If you have any questions, we’d love to offer our professional advice. Email us @ or call 0191 608088.

Taking some extra time when planning your home extension will pay off and give your project the best chance at success. Here are some of the more common mistakes people make when planning their dream extension:

#1 Not keeping an open mind or seeing the big picture!

You need to consider your house as a whole when designing any extension or alteration. It is often all too easy to focus on that dream additional space. However, you must keep in mind how you will move around in and use the rest of your home once your building works are complete.

Think carefully about: 

  • Will value be added to your property?
  • Who will use each space and is there sufficient room for how they will be using it?
  • How will you access all areas of your home? How will you get outside, for example?
  • How will your furniture taste suit the extended space? And how will the new furniture tie in with the old?
  • Will you want to phase works? If you think you may extend further in the future, should you also plan for this now?

Having a clear vision of how you would like you and your family to live in your new home is essential. Your architect will help you build this vision. Acre Design also offer up to four drafts of your design, meaning we can create a starting point and build your home extension dream from there. Exploring all possible options for your home is a really important step in the design process. At your consultation with our design team, you may find that we are able to recommend a solution or design which you had not thought possible!

If you have big dreams for your home extension but need to phase the build, it is worth putting some real thought into this early on. For example, if you would like to eventually build a two storey extension, you may start with a single storey extension first. In this case, we would advise on ensuring your footings are deep enough to support a single and two storey extension, for example. Or perhaps ensuring you have plenty of natural light as you will not be able to incorporate a roof light if you are planning to build your second storey above. You may do this for financial reasons or in order to spread out the disruption of building work perhaps?

#2 Having an unrealistic schedule

Realistically, some building work can take longer than expected. Until you break ground, there are some things you simply can’t predict or plan for. Being aware of this from the start of your project will minimise your disappointment should things take a little longer than you thought.  This will also make for a better relationship with your contractor. If an unforeseen complication arises and you are prepared for a potential delay, you will be able face it with a far more positive and relaxed attitude. Building your dream home extension should be exciting and enjoyable!

#3 Rushing into your planning application

Taking professional advice from your architect is the best way to ensure you achieve planning permission easily and without stress. Being impatient and pushing ideas your architect does not feel will get approved is a huge mistake. Architects know what they are doing and do not want your application to fail. Waiting until you have a design that both you and your architect are thrilled with, which will achieve planning permission, is a much more sensible approach.  Not all work will require planning permission. If this is a concern for you, ensure you ask your architect for advice and solutions that may avoid this part of the process. Ticking the right boxes at this stage will also ensure a smooth sale, should you choose to sell further down the line.

#4 Upsetting your neighbours

Ensuring a positive and friendly relationship with your neighbours before and during your build is very beneficial. We always advise our clients to communicate their extension plans with their neighbours as soon as they can. This means that there are no surprises and you can gauge their feelings on this. Often, building works can be disruptive to neighbouring properties. Understanding this and being as respectful and polite about it will make for an easier process for everyone. You also need to be aware of the 1996 Party Wall Act. The Team @ Acre Design are able to advise on this but you may need to create a written agreement with your neighbours about any new building work.  This agreement is usually done by a third party Party Wall surveyor.

#5 Going with a dodgy builder

It can often be tempting to go with a cheap quote for building work but it essential to consider why one quote may be so much cheaper than another. If anything, what are you missing out on? We can recommend a selection of local, reliable and reputable builders in Newcastle and the North East. Ultimately, it is your decision who builds your home extension. Ensuring you receive a detailed quote, with adequate explanation of the contractor’s process is important. If anything unexpected crops up, you need reassurance that this will be dealt with effectively and within your budget/contingency fund. Always seek references from previous clients before going ahead with a building firm. There is no safer way to check a firm’s reliability than by asking people with direct experience. We are always more than happy to put clients in touch with other clients who have worked with firms that we recommend. We also offer a service where Acre Design will act as your project manager, checking and completing contract documents and managing your build throughout. This is a more expensive method of completing your extension, however it ensures we bare the brunt of any stress on your behalf. An architect will also be able to advise you on cost saving measures, should your build quotes come in over budget.

#6 An unspecified budget

Running out of money is one of the most disastrous mistakes when building an extension. Ensure that you get fixed quotes and estimates from building contractors to mitigate this. Acre Design would always advise our clients to have a contingency fund – just in case! This will take the pressure off and if you have a bit of extra cash left over and a perfect home extension, what could be better?

#7 Being indecisive

We see a lot of clients who change their mind about certain design elements during their build. Sometimes, this is absolutely no problem and can be a really positive development. However, it can also incur additional cost if plans need updating or if planning permission applications need adapting for example. We can emphasise enough the importance of taking your time over your design. Getting it right early on will save you time and money later on.

#8 Choosing the wrong materials

Materials must be compatible with type of building you own and the period of the house. Ensuring your materials are suitable, aesthetically pleasing, energy efficient and budget friendly is very important. With a lot of experience and professional knowledge of building materials, The Team @ Acre Design are here to help! Local authorities may have guidelines about what is deemed acceptable here too so it is always best to consult an experienced architecture firm about you extension.

#9 Choosing the wrong windows

Choosing the wrong windows can make or break your extension. Researching your options and ensuring your chosen style fits with your current property is key. For more detailed advice on this, see our post on window styles.

#10 Not insuring your extension project

When you start building your extension, your existing home insurance policy may become invalid. When we get caught up with a build project, it can be easy to forget this detail. We always recommend that you contact your insurance provider to ask for advice as soon as you begin the design process. This ensures that you have plenty of time to shop around for a competitive policy and also that you don’t forget about this important aspect.

We hope that you find this information helpful, at Acre Design Newcastle we are passionate about all things design and would love to discuss your project with you.

Take a look at our recent projects for further inspiration! Get in touch to arrange a free, no-obligation consultation at your home


Right from the start, at the “needs and options review” which proved incredibly worthwhile, Alistair and his team have provided professional, thorough and imaginative service. Our project has daunted us in many ways but Alistair has always been on hand to allay any concerns we had. He has been incredibly helpful, full of ideas and specialist advice throughout the process. Our extension has now been granted planning permission and building control approval. Thanks to Acre Design this is looking so much better than anything we could possibly have imagined.

Diana Robson

Contact Acre Build

CAI Building, Royal Quays,
North Shields, NE29 6DE

T: 0191 6808 088

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