St Alban's Sinkhole: Part 2

St Alban's Sinkhole: Part 2 - Terrafirma explore the possible causes of the recent #StAlbans #Sinkhole for a recent @BBC3CR #Radio #Interview.

Early on the 6th November a ‘sinkhole’ appeared adjacent to a block of flats in a residential area of St Albans. Early reports of the collapse noted an approximately 6 metre wide hole located next to an exterior wall of an apartment building at Cedar Court. 

What is Radon and does it affect your property?


Radon is a naturally occurring, radioactive gas that forms from the decay of uranium within the ground. Owing to the way we often heat and ventilate our homes, radon can enter the house, causing exposure to this toxic gas. Every building in the UK contains at least some radon, however, in certain parts of the UK the geological conditions allow for naturally higher concentrations of radon. In poorly ventilated properties, these typically low radon levels can build up to harmful concentrations. At high concentrations, the natural radioactivity of Radon can damage the soft tissue cells within our lungs, causing an increased susceptibility to cancer (particularly in combination with smoking/ ex smoking). Approximately 1000 people die each year in the UK from lung cancer related to radon, therefore it is vital that precautions are taken to ensure that we are not living in toxic homes.

A simple screen can identify whether or not a Site/ property is within a Radon affected area (where over 1% of properties in the area are likely to have hazardous concentrations of Radon) and what level risk (low, intermediate or high). If a property is within an affected area, there is no need to worry - a simple and inexpensive measurement pack can be bought to confirm if your desired property is above the Public Health England accepted level. If the property is above the action level, then recommendations will be provided detailing the best next steps to take in order to reduce the radon level down to the target level.

Terrafirma can help by providing a Radon screen within your Ground Report (while also assessing all other ground stability hazards). This screening service will identify whether the site is within a Radon affected area and provide clear and relevant recommendations on any best next steps. Terrafirma is continually developing its modules to provide both in-depth, interpretive assessment for Ground risks and ensure that the best possible guidance and assurance is provided and that the homeowner is best protected.

The Terrafirma Ground Report is available from preferred partners of Terrafirma. To access the Ground Report, to learn more or to ask any questions please email

Environmental & Ground Hazards – do you always need a search?

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The answer – no you don’t!

A diligent property professional will always recommend undertaking searches for each transaction, so the purchaser can paint an accurate picture of any hazards and restrictions that may affect their future home. Certain environmental risks such as contaminated land, radon and flood are well understood and established in general due diligence during the conveyancing process, however other environmental hazards, namely mining, natural ground perils and planning are not. 

A contaminated land search, and often a flood search are both commonly undertaken as standard, regardless of location, property type, size, proposed use or client. There have been attempts to screen this data so searches are only required in areas deemed to be ‘at risk’, however due to poor datasets and interpretation, more often than not you have to spend large amounts of your clients money when the risk to their property could be non-existent, all so you can make sure that you, your client and the lender are covered by adequate insurance. 

However, when we assess environmental and ground hazards properly, we know that not every property is in an area deemed to be ‘at risk’ – it’s time to stop capitalising on poor data and increase transparency and awareness around these hazards. 

We are not saying there aren’t risks posed by the environment – in fact, quite the opposite! Flood events can have a devastating impact on property value, use, enjoyment and livelihoods and it is essential the potential for them to occur is assessed by experts. The same goes for the risks the ground pose and for emerging ‘emotional’ risks such as Fracking and planning. 

But why do you need to purchase a report in every case? Especially, when you purchase a report and it comes back with not only a ‘pass’ but looking deeper, it actually doesn’t identify a single point of interest. On average, this happens 30% of the time, which means almost a third of your disbursements could be reduced by between £50 - £100!

There is a big difference between a search being returned with a ‘pass’ with a professional opinion that has identified risk(s) and mitigated against them using expert interpretation; and a search being returned as a ‘pass’ that has not identified a single risk within several hundred metres. If you have the former, the client can be safe in the knowledge that they are making a sound purchase and you have undertaken your due diligence justifiably, the latter just feels like daylight robbery. 

So how can we change this?! Is it possible? – absolutely. We have come a long way since the early days of searches, technology has become exponentially more advanced, the ‘data’ race and smokes and mirrors around who has more data has been disrupted and data interrogation and analysis is now so powerful that Terrafirma can monitor the ground moving in ‘real time’. This level of data interrogation allows for positive disruption of where, why and how you undertake ground and environmental due diligence. 

For contaminated land and flood, it is likely that significant investments will be made over the coming years into refining data so that a search isn’t necessary on every case. But, for one group of environmental issues, this science-fiction future already exists. Ground risks have already been modelled and assessed by Terrafirma to a level that we can now  confidently state that; for over 30% of the country, there is no need to carry out any additional due diligence by ordering a The Assure Certificate - you need only obtain a certificate that can be stapled to your Report on Title for a small cost of £15 + VAT. 

This certificate will include robust terms and conditions, including £10 million Professional Indemnity (per certificate) and a professional opinion that will state that there no risks have been identified that will impact upon the ongoing use of this property or site. It will have still looked at all the data, but importantly not just data, it will have interrogated the advanced risk models that Terrafirma have worked tirelessly on for all ground hazards. Complete peace of mind, complete protection against liability, for a fraction of the price. 

The risks the ground poses are still an emerging risk in the conveyancing process, a group of environmental issues that haven’t had the limelight that flood, and contaminated land has over the past two decades, but that isn’t to say it isn’t an issue that doesn’t deserve our professional respect. Recent changes to legal guidance and best practice around mining and ground perils is testament to the potential liabilities, similar in almost every way to the physical, legal and financial liabilities posed by flooding. 

Importantly though, like all the other well-known environmental issues, these varied and complex risks posed by the ground like subsidence, mine shafts, landslides and radon are not an issue everywhere. There are huge numbers of properties, particularly in urban centres, that are free from any risk at all – even in places like Cornwall and the depths of the mining towns in Nottingham and Yorkshire. 

So, it is here we begin our mission to educate property professionals and the public alike that you do not need to always undertake an expensive environmental search or mining report, instead getting a humble certificate – appropriately named: Assure. 

Assure represents the future of environmental risk assessment, where advanced modelling has been able to instantly analyse the potential hazards present and remove the requirement for any additional expense, delays or reports in over 30% of cases. There is a long way to go before the same can be offered for all environmental issues, but Assure is a positive step in the right direction. 


Assure is available from preferred partners of Terrafirma. To access Assure, to learn more or to ask any questions, please email:



An Innovation in Cornish Property Risk Assessment

Terrafirma collaborates with Cornish Mining Experts to bring new Ground Report to the South West

Cornish mining expert, Cornwall Consultants and national mining and ground report specialist, Terrafirma, have announced a collaboration that sees the launch of a new Ground Report combining leading digital mapping and data analysis with ‘on-the-ground’ experience and expertise to bring clarity to the current confusion among property buyers across Devon and Cornwall caused by the disparate mix of products available to them.

The Ground Report from Cornwall Consultants will see customers benefit from the widest range of the latest ground stability information relating to coal and non-coal mining, natural ground issues and even fracking combined with a vast mining archive and wealth of experience working in the region. The Ground Report includes an expert professional opinion, risk assessment and risk transfer and satisfies new Mining and Ground Perils guidance in the Law Society Conveyancing Handbook.

The Impact of Coal Mining

Explore the legacy the UK's once great coal mining industry has left on property and land in Terrafirma's new Infographic. With almost a third of all buildings in the UK underlain by coal mines, over 9000 recorded hazards and a new mining subsidence claim made every week of the year, it is essential to understand the risks present to form intelligent reporting and management solutions for professionals and public alike.

Click the link and read on to explore in more detail about the impact of coal mining on property and land across the UK:

Introducing: The Ground Report.

Terrafirma launches pioneering new report to improve understanding and management of the risks the ground poses. 

Terrafirma, an expert provider of environmental information and data intelligence, today launched the Ground Report, a risk and liabilities report designed to enable property professionals to better identify, manage and resolve ground and environmental hazards. The Ground Report satisfies recent new best practice guidance on mining and natural ground perils, published by The Law Society in the 25th Edition Conveyancing Law Handbook.  

For further information on the Ground Report visit or call 0330 900 7500.