10-Point Due Diligence Checklist

So you're ready to build...  But have you done your due diligence?

BetterLivingSpace has put together this essential 10-Point Due Diligence Checklist to action before embarking on a property development project.


These 10 simple checks can bring to light the most common issues before you spend any money on architectural design, resulting in significant cost and time savings.

1. Research Restrictions

First and foremost, check with your conveyancing solicitor whether you have any covenants or restrictions on your plot of land. If you do, you will need to investigate carefully with your solicitor and architectural designer to determine if any development whatsoever will be possible.

2. Consult the Planning History and Past Development

Contact both your Local Planning Authority and Building Control. Request all documentation relating to your property’s structural history and the planning records for your plot. These will detail the original footprint of the property and any previous structural or development work, enabling your architectural designer to assess if your plans are feasible. Generally speaking, if your property is already twice as large as the original footprint then careful consideration needs to be given by your architectural designer.


3. Take Note of Special Mentions

Check via your Local Council planning portal if your property:

  • lies within a restricted zone, such as Green Belt, Area of Outstanding Natural Beauty or Conservation Area;

  • is listed or specifically mentioned.

You can also use the Historic England website to research for listed property.

These issues could affect your planning application, or impact what you can achieve. They will almost certainly impact your design approach and development application. In general, volumes and sizes are of most importance in Green Belt areas, whereas aesthetics are of greater consideration in Conservation and Outstanding Natural Beauty areas.


4. Consider the Environment

Research via your Local Council planning portal if your property is situated within the vicinity of:

  • ecology, bats or protected trees;

  • regions of designated Special Scientific Interest (SSSI) or a Special Protection Area (SPA)

These issues will need to be discussed and mitigated with your architectural designer before you submit for Planning Approval. You may need to purchase a specialist report to determine the impact your development plans will have on the surrounding area, which can cost anything from £1000-£5000. While costly, it is money well spent as it will greatly influence the success of your planning application.


5. Assess Flood Risk

Use the government interactive flood risk tool to ascertain if your plot of land lies within a high risk surface water flooding zone, or within an actual flood risk area. Both of these could impact the potential of your development project. Your architectural designer may also include mitigating design features to counter low level flood risk. 

6. Check Your Permitted Development Rights 

Contact your local Council to check there is no reason your property would not be eligible for Permitted Development Rights.  A quick check could save you the cost of submitting a Permitted Development Application, only to have it refused. This check is most relevant for new build properties, which do not always have Permitted Development Rights.

7. Dig to the Depths of Your Foundations

Have a local builder dig a ‘trial hole’ alongside your existing foundations. This is literally just a hole in the ground to determine the depth of the current foundations. It should not cost more than around £300 to carry this out. If you have the time and equipment, you could even do it yourself. Knowing the depth of the foundations is critical information, which will drive the cost and possibilities for the whole development infrastructure.

8. Discover What Lies Beneath

Conduct a drainage survey. This costs around £200, depending on the number of drains you have. It is important to understand what exactly is going on in the depths of your plot. You do not want to discover halfway through the build that there are drainage chambers or deep sewers lying under your lawn!

9. Will Your Plans Need a Party Wall Agreement?

If your development encroaches within 3m of a neighbouring property then the Party Wall Act may apply. In a perfect world, your neighbours would be completely amenable to your development works and happily sign a Party Wall Agreement. In reality, you may need to engage surveyors to produce a Party Wall Award, which will cost around £1,000. The best approach is to engage in open communication with your neighbours as early as possible, to help foster their understanding and support of your development project.  

10. Take Account of Local Authority Design Guidance

Request a copy of the Local Plan Documentation and Design Guidance from your Local Authority to understand the recommended styles of new residential development and extension work.  Does the guidance correspond with your ideas?  If so, then you are at least starting on the right track to gain Planning Approval. If not, you will need to discuss your ideas with your architectural designer and think creatively about how you can make adjustments and where you would be prepared to compromise in order to breach the gap.

Now... Go Design!

After researching the 10 due diligence points on this list, you should be in a good place to start working seriously on your project with your architectural designer.


At BetterLivingSpace we carefully consider each individual project, taking action on these due diligence points as a bare minimum before we start the design process. If you would like advice and guidance on the possibilities to develop or improve your home, please contact us via the Contact page or enquiries@betterlivingspace.com.