Yes, subsidence in London is a common problem and can be caused by several different reasons. The main one being London’s clay soil which shrinks and swells depending on its moisture content and nearby trees or drains causing damage to structural foundations.
Soil softening or erosion of soil are also to blame for subsidence in London in certain soils. Leaky drains can cause the ground to soften considerably resulting in subsidence. Construction work and vibrations from heavy traffic and machinery can also cause movement in the soil leading to subsidence.
Most of our structural inspections involve cracks and movement, so our main interest is in the exterior and interior walls of the property.
Our Chartered Structural Engineers only carry out visual inspections. They don’t undertake any intrusive exploratory works as part of the initial site visit and written report. In rare cases, more detailed, follow up exploratory work might be recommended but this is rarely practical or necessary during the process of selling or buying a property.
When the property is an apartment, it is rarely practical to gain access to neighbouring properties or gardens beyond the subject property.
As highly experienced Chartered Structural Engineers we can report decisively following a site inspection, without the need for invasive work or protracted monitoring.
There are parts of a property that we do not inspect. We are Structural Engineers and not Surveyors, so our report work does not cover items such as damp, water ingress, windows and roof coverings or services.
Cracks could be a sign of subsidence, which will usually entail costly structural work, difficulties in acquiring buildings insurance or when putting the property onto the market. So which type of cracks are serious?
Cracks wider than 5mm are likely to be serious and in need of professional repair. Smaller cracks of 2mm to 5mm but which occur both inside and outside on an external wall may be a concern depending on whether they are progressive or not. In very general terms cracks from hairline to 2mm or normally deemed normal plaster or seasonal cracks and are rarely an issue unless they are the beginnings of something more serious. It is for SERL to use their experience to establish the implications.
If the crack extends through the entire wall thickness and is tapered and wider at the top than the bottom, it might be an indication of structural movement.
Cracks which correspond internally and externally are usually structural defects and not simply cosmetic plaster cracks.
Do be aware that small cracks could evolve into something more problematic. When cracks increase in width over time, they should be investigated. These types of ongoing cracks are of particular concern to surveyors, mortgage lenders and insurers, because they might lead to expensive repair work in the future and make the property more difficult to re-sell.
A qualified Structural Engineer will be able to advise you on the seriousness of any cracks.
Yes, SERL can provide estimated repair costs based on our general experience. These will be a guide only. A detailed specification of works will be needed for any repair work to be costed accurately by a builder. However, our estimated costs will normally be sufficient to inform a buying or selling decision. SERL does not prepare specifications or oversee building work, but our colleagues can assist.
Yes, SERL can recommend builders for structural repairs, and we will only recommend qualified experts who have the relevant specialist knowledge and skills to repair the property.
No. In most cases our Structural Engineers Reports are sufficient to inform an experienced builder or repair specialist about what needs to be done. In complex or larger cases, our affiliate company can be involved in the subsequent specification and repair process.
We don’t offer these types of reports. However, we can recommend firms of Chartered Surveyors that do carry out homebuyers reports and building surveys.
No, the term structural survey can be misleading, as it implies a level of structural specialism where there is none. The term Structural Survey is sometimes incorrectly used to mean a full BUILDING Survey by an RICS qualified Surveyor, now called a level 3 RICS Survey.
As there is often confusion around these terms, it is important to confirm with your chosen firm that they will be providing the specialist Structural Engineer’s expertise you need.
A Structural Engineers Report is most requested when a RICS Surveyor highlights concerns about cracks or movement in a property.
Please note that your Structural Report should be undertaken by a fully qualified MEMBER or FELLOW of the Institution of Structural Engineers as this is the only qualification approved by all lenders and insurers.
In most case it will be the buyer who will wish to rely on the report and therefore they will instruct the Structural Engineers Report on their own terms and pay the fee. They might sometimes negotiate reimbursement from a vendor but there are no limitations to this.
In a situation such as a lack of building regulations approval for alterations, the vendor might agree to pay for the Structural Engineers Report or contribute to the cost. Sometimes a proactive vendor might commission a report prior to advertising a property for sale to ensure they are aware of any issues and to be entirely transparent with buyers. This can improve buyer confidence and is highly recommended when there are known cracks which will likely need a Structural Engineers Report in any event.
A General Structural Inspection (GSI) report will detail the general condition and structural integrity of the property. The Structural Engineer will inspect all the accessible load-bearing walls of the property to detect any structural defects and provide guidance for any necessary remedial works or further investigations that might be required. The written report may also provide estimated costs for any repairs if requested.
A GSI report may be required because of an overall tilt in the building or because there are significant structural concerns in various parts of the building. The inspection may include the surrounding environment to assess any risks to the foundations of the property, such as large trees or drainage problems.
A Specific Structural Inspection (SSI) report will focus on a specific localised part of the property or a single structural problem. This SSI report is often instructed following a Surveyor’s report which has been carried out for a property valuation.
A Structural Engineer’s Specific Structural Inspection will focus on the particular structural problem, such as a crack above a door or a bulge to a wall. Other parts of the property unrelated to the specific problem will not be inspected. The SSI report will include details of what was inspected and found during the structural inspection, along with recommendations for remedial work or further investigation. When repairs, or further investigations are required, the report will supply estimated costs if requested. It is important to understand the limitations of this type of report and that SERL also offers a more comprehensive General Structural Inspection (GSI) to assess the structural integrity of the building.
Settlement occurs as a result of the weight of a building squashing the soil, whereas subsidence of the soil occurs entirely independently of the weight of a building. For instance, a conservatory might experience subsidence, yet the Shard office building in London which has exceptionally deep strong foundations does not.
Settlement sometimes occurs in a new building and is caused by the ground compacting beneath the weight of the building.
Older London houses might be prone to settlement soon after they were built due to their simple shallow foundations. Small plaster cracks are not normally causes for concern. However, if any movement or distortion threatens the safety of the building, it is wise to act and call in a professional qualified Structural Engineer as soon as possible. They will help to determine whether the property has structural and foundation issues or just normal plaster cracks or minor seasonal movement.
Subsidence in London is more common than anywhere else in the UK. Subsidence is the vertical downward movement of a building foundation caused by the loss of support of the site beneath the foundations. Clay soils, large trees growing close to the property or leaking drains are all possible causes.
Subsidence happens when the clay soil of London shrinks and moves downwards, withdrawing support of the building above. This commonly occurs when tree roots remove water from the subsoil so the clay shrinks causing the foundations to sink.
Subsidence can be is serious and the cause needs to be dealt with in order to limit and prevent ongoing damage and matters becoming worse.
If you are concerned about subsidence, it is essential to consult a Chartered Structural Engineer for expert advice to put your mind at rest or to resolve any
It can prove to be false economy not to invest in a Structural Engineers Report, as in the long run any structural issue could result in even costlier repairs in the future. You could also find yourself owning a property in London that you regret buying and would not have bought if you had been completely knowledgeable about its condition.
The impartial, accurate and detailed information provided by a Structural Engineers Report can be crucial in deciding whether to purchase a property or not. In addition, information about any repair work needed to fix the defects and the associated cost could be used to renegotiate the final price.
An early report by the vendor can improve buyer confidence and speed up sale transactions by being proactive, transparent, and honest. This is particularly useful when there are known cracks or other flaws which are bound to concern a Surveyor later in the process. Conversely, having a Structural Engineers Report that gives the property a clean bill of health will provide a prospective purchaser with confidence.
A property in London with structural defects will inevitably lead to a requirement for a Structural Engineers Report before a mortgage lender agrees to release funds. The Report will also be a requirement for most building insurances.
A Structural Engineers Report will inform a potential buyer about issues such as subsidence, which can seriously affect the value of your home and ability to sell.
SERL is often appointed to carry out detailed, non-intrusive, visual Structural Engineers Reports for all types of properties.
A structural Inspection and report may be required for many reasons, whether it’s a requirement for a mortgage application, for insurance purposes or simply for peace of mind.
If the property in London is showing signs of subsidence such as cracking or movement of the walls, it will be advisable to engage a professional Structural Engineer to carry out a General Structural Inspection (GSI) of all the loadbearing walls.
If the property in London has a single structural fault which is confined to one part of the property, and you do not require the Structural Engineer to inspect the whole building, a Specific Structural Inspection (SSI) and report will be sufficient.
SERL can provide a GSI or SSI report to suit your specific needs.
The Certificate of Structural Adequacy was a term first introduced by the buildings insurance and Subsidence repair industry around 1994, following the publication of the Institution of Structural Engineers report entitled ‘Subsidence of Low-Rise Buildings’. Its intention was to simply summarise the advice provided following lengthy subsidence investigations such as soil testing crack monitoring, and drain tests, and the eventual design, specification of an underpinning scheme or specialist structural repairs.
The recent 2023 guide titled ‘Subsidence, also published by the Institution of Structural Engineers states “The expert chosen to carry out the INVESTIGATION should decide what remedial works if any are required. If no major works are necessary, a Certificate of Structural Adequacy can be issued by the expert at this stage”. Subsequent text then explains the design, specification, and supervision in instances where the investigation has resulted in remedial works of some sort.
The IStructE guide states “Such a Certificate would not be a Warranty or Guarantee but it would be a considered professional opinion by an Expert”.
The Certificate does not provide an indemnity or Insurance for an old building, nor does it certify the work of a builder who might have recently carried out repairs, which were not specified or supervised by us.
In short, the Certificate of Structural Adequacy is merely a more concise summary of the SERL report, which is always prepared for each property inspected and which you may rely upon, as you would the advice of your Solicitor or other professional person. Our reports are backed by SERL’s professional Indemnity Insurance of course.
Do note that most of our reports only inspect and report on part of a property, often just one wall or a single crack and so there will be obvious limitations to our advice. Any mention of a Certificate of Structural Adequacy could infer much greater responsibility than is intended.
Certificates of Structural Adequacy were intended to follow Insurance claims by owners, where more time was given to Investigate a potential subsidence case. In contrast, a pre-purchase survey is merely a snapshot in time and offers a brief inspection of a vendor’s property. It does not offer the opportunity to monitor or excavate or and investigate a defect over time.