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Allan CorfieldMay 16, 2018 12:00:00 AM8 min read

The Most Common Mistakes In Self Build And How To Avoid Them - Part 2

Undertaking your first self-build venture is uncharted waters for most, especially if you do not have experience in the construction industry or in managing large projects. Fortunately, you are not alone. Many, now successful self-builders had the same fears before embarking on their first build. In Self Build, like many areas, it is easy to make a mistake that can be costly.

ACA have been in the industry for over ten years now and have witnessed various problems that emerged due to a self-builders’ lack of experience. But do not worry, we have you covered. We believe that it is best to learn from the mistakes of others, therefore we decided to create this two-part series about the most common mistakes that self-builders make with our tips on how to avoid them.

We divided this series into two articles covering five different areas in which self-builders can encounter difficulties, these are:

  • Problematic sites
  • Design not meeting your expectations
  • Trouble with professionals
  • Running out of money
  • On-site issues

If you read this series you will be aware of potential issues that can occur in those five areas, and hopefully, you will be able to avoid them. However, if not, you will be able to deal with them at an earlier stage before they will cause serious damage to your project and budget. This is the second part of this guide and will discuss the common mistakes in managing the self-build budget, on-site issues and problems with professionals.

If you didn’t catch part one of the article then click here, before reading on!
common mistakes self build


Obviously, you cannot build your house by yourself. You will have to appoint and rely on some professionals to make your dream come true. It is not easy to get the right professionals, so in the first part of this guide we will look at who you will need to appoint and how best to make the appointment!

As a basic requirement, you will need an architect or architectural designer. Then you will need a structural engineer, and possibly a planning consultant (depending on how difficult your site is). If you want to cost out the whole build, a quantity surveyor will be helpful, and a heating engineer will provide a detailed heating strategy. If you do not have time to manage the whole project you may need a project manager. Additionally, depending on your requirements, you may find working with landscape, interior or a lighting designer’s useful. 

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Here are some tips that may be helpful when appointing professionals:
  • Always interview at least 3 of each professional. Obtain three quotations and references. Do not ask them for their best three references; ask for their last three jobs, or even better…what projects are on-site at the moment! If they are not willing to provide you with those details – they are probably not the right people to work with.
  • Make sure that you agree on a fixed cost. Experienced specialists should be able to accurately estimate how much their service will cost and not rely on a % of construction cost!
  • Interview people who have experience in the type of building you are proposing, for example, do not go to a large commercial practice for a small extension.
  • As a self-builder, you will want to negotiate the conditions in order to save as much money as you can. Remember that every business has to be able to cover overheads and make a profit or they are not going to be successful. Try to negotiate but do not fight them down on cost too much.
  • After every stage, your architect should ask you if you are happy with the work and whether they can go to the next stage, you must love the design! Communication is vital, and it works both ways, so stay in touch, by whatever means (text, email, skype or good old fashioned telephone)!

For more tips on how to minimise the chance of appointing unreliable specialists, read our article here.

common mistakes self build


From our experience, we know that a lot of self-builders make the mistake of not organising their finances and budget before starting their self-build journey. This is a recipe for disaster!

Before you start spending money on your project, consider all the options on how to fund your project. Before you even speak to an architect, make sure that you have discussed the project with someone like BuildStore, they will guide you in the right direction.

Do your research to find out whether it is beneficial to get a mortgage. As a self-builder constructing an energy-efficient house, you will find that there are very competitive (reduced) rates, which are linked to the energy performance.

Get fixed costs throughout the whole project, for all products and sub-contractors.

Analyse your cash flow…. cash flow is king! You must treat this as a commercial venture, and make sure you can fund each stage of the project. The majority of self-build mortgages are on a stage release basis which means that you have to finish one stage of your project before the money is released to cover those works and materials.

At the beginning of your project, you will not only have to pay for the groundworks but also pay a deposit for a kit (SIPS, Timber frame), windows, doors etc., so you need to be able to cover a huge amount in that first stage. As stated before, cash is king – you may have a large enough budget for the whole project but if you can’t release funds at the right time, you may never get wind and watertight!

common mistakes self build


Unfortunately, we can’t cover all of the on-site stuff (that could be a whole other article), but we can cover basic steps, that if completed before you start on-site, then they will make a huge difference!

If you want to avoid problems on site, you must plan everything precisely before the work starts. The first piece of advice is not to rush onsite and start building, without taking stock – we appreciate that the planning may have delayed your project,  but don’t rush. Instead, plan every stage carefully. This small delay will help you to save money, in the long run. Once everything has been approved, you have dealt with your planning conditions, step back and plan each step on site. Consider who you are going to appoint and what tasks they are going to perform and who they will hand over to.

Being the project manager for your Self Build will save money. You can create a timeline of your project using basic Gantt charts. Creating a timeline will facilitate an efficient planning process, thus ensuring it will go smoothly and according to plan.

One area which you can’t forget about is obtaining your latent defect policy, this must be in place prior to starting any works. This is similar to the NHBC 10-year policy you see advertised with new houses. This provides a warranty which covers the quality of the works for the next owner. If you do not have this, when you come to sell your house the next owner will not be able to obtain a mortgage for the home. Remember, that you need this prior to starting works on your site, otherwise the policy will go from about £2,500 up to £5,000! Worse still they may even refuse to give you insurance if the works completed are not up to a suitable standard.

common mistakes self build

Companies such as Protek and BuildStore provide a full package of insurance, covering everything you need for your Self Build – remember you will also need site safety, public and employers liability insurance.

Making changes on site happens regularly but this can be costly and may have unforeseen issues later down the line. It is always better to take longer during the design stages, giving each detail of the construction the right amount of thought and time. Making changes on site are regularly agreed between contractors, you must involve your architect and engineer. They will need to check that the potentially simple change, doesn’t impact planning or building standards approval or another follow-on trade. So if you have to make a change, please make sure you consult all of the relevant parties.

A final small hint is to hold a pre-start site meeting with all of the sub-contractors, prior to finalising their appointment. Get them all around a table and agree what each of their tasks are, and importantly who they will handover to. Also, this is a good point to get them to agree to any other small jobs and to confirm that they will tidy up after themselves – if they are waiting for an appointment you will be amazed at what you can get them to include. Make sure you or your architect prepare minutes the meeting and issues them out as part of the formal appointments!

This was the second and final part of our series describing the most common mistakes that self-builders can make. If you have still not read the first part, you can find it here.

If you take into account all of our advice and keep it in mind throughout the project, you can start your project with confidence – knowing that you have reduced the chance of making mistakes that could cost you a lot of money! Good luck and enjoy the journey…

More guides based on Allan’s talks from the Homebuilding & Renovating Shows available below:

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Are you preparing for your self-build journey? Or maybe you have already begun? Did you make any costly mistakes? How did you avoid mistakes? Share with us in the comments section.