Monday, May 14, 2018

Party Wall etc. Act 1996 – Much more than just Party Walls!



It is easy to see how the Party Wall etc. Act can be mis-interpreted, particularly by members of the public, just by the nature of its title.  For those who work in the property professions and interact with the Act on a regular basis there will be generally less confusion, however in my experience this is not always the case!

Source: tayrosshomes.com
Although there is a lot of information available about the Party Wall etc. Act 1996 (the Act), and its implications, it appears that there is equally as much mis-understanding or even ignorance about the Act, particularly from members of the public in relation to if and when the Act may apply.  Awareness of statutory approvals such as Planning Permission and Building Regulations approval seems to be improving, however, the existence let alone the requirements of the Act, often comes as a complete surprise to many.

If you are proposing certain types of work on your land or to your property then you may be required to ‘notify’ your neighbour under the Act. It is worth pointing out at this point that the requirements and procedures within the Act are completely separate to other statutory permissions such as Building Regulations and Planning Permission.  On a number of occasions I have been informed by householders that they were either not made aware of the requirements of the Act by their advisors or that they thought that they had obtained all of the relevant permissions because they had Planning and Building Regulations Approvals, which is completely incorrect.

If you are proposing any work to your land or property it is worth undertaking a little research to establish if the work falls under the scope of the Act and therefore will require notification to your neighbour/s (referred to as Adjoining Owners under the Act).  As you would expect, I would always advise you to seek professional advice to confirm whether notification under the Act is required and if so to also guide you through the process, however, nowadays, with the raft of information available on-line, there is no reason why you shouldn’t undertake your own research in the first instance to give you a better understanding of the Act. The Ministry of Housing, Communities & Local Government (formally the Department for Communities and Local Government) have produced an excellent explanatory booklet, which explains the Act in a clear understandable manner and is a really good starting point, particularly for those with little or no knowledge of the Act. You will find a copy of the booklet by clicking on this (link).

You may be surprised by the range of different types of work that are notifiable under the Act, which you will see are not just restricted to a party wall itself. The Ministry of Housing, Communities & Local Government’s booklet defines a party wall as, ‘a wall is a "party wall" if it stands astride the boundary of land belonging to two (or more) different owner’. The booklet then provides some illustrations to demonstrate this point. It is interesting to note that the definition of a party wall is not just restricted to a wall inside a building, but can also relate to external walls also, such as boundary walls. The Act uses the term ‘Party Fence Walls’ to describe walls that are not part of an actual building itself, however may still require notification under the Act for works to, or in close proximity to them.

Source:My property guide
The term ‘etc’ in the title of the Act is also significant. Three innocent little letters (etc.), however the implications of the term denote that the scope of the Act is much wider than just Party Walls. In fact some works that require excavations near neighbouring buildings may also require notification under the Act. Section 6 of the Act requires notification of excavations within 3 metres or within 6 metres of a neighbours building or structure based upon the following criteria:

‘excavate, or excavate and construct foundations for a new building or structure, within 3 metres of a neighbouring owner’s building or structure, where that work will go deeper than the neighbour’s foundations;

or excavate, or excavate for and construct foundations for a new building or structure, within 6 metres of a neighbouring owner’s building or structure, where that work will cut a line drawn downwards at 45° from the bottom of the neighbour’s foundations’

The six metre ‘rule’ is a little more complicated to understand (see the diagram below) than the three metre ‘rule’ and usually relates to deeper excavations such as piled foundations and the like. It is also worth noting that the six metre rule can affect more than one adjoining owner, depending upon the depth of excavation and the proximity of adjacent buildings and structures. In order to establish how many adjoining owners may be affected in any instance by the six metre ‘rule’ it will be necessary to take measurements and produce a section drawing which will detail the depth of the proposed excavation and the location and proximity of adjacent structures and buildings. Professional expertise is highly likely to be needed to take measurements and to produce a section drawings to establish if and how many adjoining owners will be affected.

Source: My property guide
Another term used within the Act is ‘Party Structure’. This again suggests that the Act does not relate exclusively to party walls. In fact there are a number of notices that may be issued under the Act, one of which is a Party Structure Notice. The reason the notice is not entitled a Party Wall Notice, is that this would be misleading and not account for any works other those to Party Walls. Party structures are generally defined as dividing structures such as floors and other partitions, however it is very rare that these structures are subject to party wall notification.

In summary it is easy to see how the Party Wall etc. Act can be mis-interpreted, particularly by members of the public, just by the nature of its title. For those who work in the property professions and interact with the Act on a regular basis there will be generally less confusion, however in my experience this is not always the case!  As notification under the Act may be required for a whole range of different types of work, as defined in section 1, 2 & 6 of the Act. All construction professionals, regardless of discipline should have a good understanding of the Act including its procedures.

In my next article I discuss retrospective party wall notification and in future articles I will consider different types of notifiable works in more detail, as well as tackle the thorny issue of fees under the Act.


Author: Gary O’Neill

Please feel free to share this article and other articles on this site with colleagues, friends and family who you think would be interested

Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read thecopyright notice at the end of the blog.

Tuesday, May 8, 2018

The Romans - The Original Master Builders - Part 2



I doubt that the modern buildings that we are constructing today will leave a similar legacy to that of the Romans. If we could make the same positive impact that the Romans made to the built environment then we will leave behind a similar positive lasting legacy for our future generations

A Roman Hypocaust - Source: www.pages.drexel.edu
In my last article I demonstrated how the Roman occupation of the UK left a lasting impression on our built environment and how the introduction of new building techniques allowed larger, bolder buildings to appear, the like of which had never been seen before in the UK. I also explained that the location of towns and cities was carefully planned to make optimum use of the natural resources available in a particular location, and how gravity was used to provide fresh flowing water into towns and cities often using lead pipes, sometimes over great distances incorporating aqueducts which make use of masonry constructed arches. For the rich and important in Roman society their homes and other buildings became status symbols. The size of the building, the inclusion of mosaics and painted plastered walls, under floor heating and fresh running water would demonstrate how rich and powerful the occupant was.  

Larger Roman houses were designed around a central atrium. You can see from the image that a Roman atrium would have no roof and would therefore be open to the elements. A recess or trough would be built into floor which would collect rainwater, which would be used for many different things including drinking and washing. You could say that this is an early form of rainwater harvesting! something that is becoming increasingly popular today. Various rooms would then be designed directly off the atrium for which the amount and use of the rooms would depend on the size and status of the building. Larger Villas/houses would incorporate a second atrium, something referred to as a Peristylium, which would include a garden area and would also be designed to have rooms access directly off it. The orientation of the building would be designed so that Peristylium would be able to catch as much sun as possible, however for comfort, in warm weather the courtyard would also incorporate trees to provide much needed shade. 

A Peristylium - Source:The Desert Sun
If you ever watch programmes such as Time Team (for those who do not know, this is a TV programme where Archaeologists, Geo-Technical Engineers and Historians have three days to unearth and re-construct a particular building/structure), you will see that there is always a great deal of excitement when they suspect they have unearthed a mosaic. The reason for the excitement is because this will often tell the Archaeologists that they have found a significant or high-status building. Mosaics were usually constructed within floors however wall mosaics were also used.  Making an elaborate mosaic was a task that would require the skills of a master mosaic craftsman would set out the picture/design while others would complete the actual work of making the mosaic. Small pieces of stone or clay would be used to create the image of the mosaic which would often depict a historical event, have a cultural or spiritual meaning, possibly depict an animal or even be an elaborate geometric design. Some of the best examples of Roman mosaics in the UK can be seen at Fishbourne Palace in West Sussex where Archaeologists discovered a number of elaborate mosaics which they have dated back to AD75 – 80, making them the oldest discovered mosaics in the UK. The mosaics at Fishbourne Palace provide a good insight into the skill that would have been necessary (to design and construct), remember over nearly 2000 years ago, to produce such elaborate designs. 

Arguably, one of the most innovative ‘inventions’ that was introduced by the Romans was under floor heating. It is staggering to believe that this would have been possible at the time however palaces, bath houses and high status buildings would often incorporate under floor heating, which was provided by a system know as a hypocaust. A hypocaust comprised a raised floor which would typically incorporate a two foot (600mm), void underneath. The void would be created by the stone floor surface being supported off pedestals (small columns). Heat would then be introduced into the void by a furnace, where a person (usually a slave) would ensure that a fire was continually burning.  As the heat would built in the floor void the stones forming the floor surface would start to absorb this heat, which through conduction would eventually increase the temperature at the floor surface, this would heat the rest of the room as well as the floor. Furnaces were reasonably large and therefore took up a lot of space so the Romans usually designed these to be out of sight and therefore located them in an adjoining room.  

The Romans were so ingenious they even thought about ventilation!  As you would image the furnaces used for the under floor heating system would also create a lot of smoke/fumes, which needed to be directed away from the internal spaces. The Romans dealt with this by building spaces into walls, known as flues, to provide a safe path for escaping smoke and fumes. Excavations at Ashtead Villa in Surrey revealed that the Romans used box flues to vent hypocaust systems. ‘Box-flues are hollow box-like tiles set into walls to allow hot air from an under floor hypocaust to heat the room walls’  Source: www.thenovium.org

Roman hollow box tiles - Source: http://www.thenovium.org
There is no doubt that Roman Architecture and Roman Engineering was well ahead of its time, evidenced by the vast array of buildings and structures that still exist today in many parts of the World. Within this and my previous article I have briefly discussed a small number of Roman techniques such as rainwater harvesting, the use of mortar, the use of arches, under floor heating, ventilation etc. for which although technology has developed, these are still used extensively today. I doubt that the modern buildings that we are building today will leave a similar legacy. If the earth still exists in 2000 years (a completely separate discussion!), what conclusions will the people of that time draw about us and the built environment we are creating now? If we can make the same positive impact that the Romans made to the built environment then we will leave behind a similar positive lasting legacy for our future generations. I suspect however that very little of the World we are creating today will remain compared proportionally to the amount of Roman remains that exist today. This really tells its own story. If I am around in 2000 years I will be more than happy to be proved wrong!


Author: Gary O’Neill

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Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.

Monday, April 30, 2018

The Romans - The Original Master Builders - Part 1



There was nothing random about the location of Roman villages and towns. Even before construction would commence the Romans would carefully select where towns and villages would be sited. These were carefully planned to make optimum use of natural resources such as food, water, timber, stone etc. in a particular location

The Colosseum - Source: Gizmodo
One of the wonderful things about living in the UK is our diverse history and what this history has left behind as a reminder of different historical period. This is no better demonstrated than in our built environment where there exists many wonderful buildings/structures that provide us with an insight into bygone cultures, politics, classes, lifestyles, technologies and the like. It is only by looking at our historic built environment that we can fully appreciate the skills and ingenuity of the people of their time. Our predecessors would not have had access to modern building equipment and modern techniques that are available today. Nowadays with the use of things like digital laser measuring equipment and off site manufacturing we are able to work to high levels of accuracy allowing us to design to extremely tight tolerances, something I am sure our predecessors would never have ever dreamed of. Therefore, next time you look at an older buildings, possibly a heritage building, just take a few moments to appreciate the skill, ingenuity and blood and sweat that would have been necessary at the time of construction in order for the building to be robust enough to be standing, often hundreds or even thousands of years, after completion. 

From a built environment point of view in the UK, a significant period in history was from circa 43AD to 410AD, which is when the Romans occupied large parts of the UK as well as most of mainland Europe. At the time the Romans were extremely powerful and were able to take occupation of pretty much anywhere they wanted due to their superior military skills and power. The Romans brought with them technical skills and building techniques never seen before in the UK. This allowed them to stamp a lasting mark on the UK, for which the large amounts of remaining Roman buildings, structures, roads and remains bare testimony too even today, nearly 2500 years after they were first built!

Roman Road - Source: realmofhistory.com
Firstly, let me dispel a myth - most would associate Roman buildings as large masonry constructed villas, with painted plastered walls, mosaic floors and running water etc. This is largely down to the media as when a film or documentary about the Romans is broadcast, this is what is usually portrayed, however these larger masonry structures were inhabited primarily by the rich and powerful, and the reality was that most people during the Roman occupation lived in timber constructed buildings similar to the Celts who preceded them. It is from the larger masonry villas and structures that more advanced building techniques were introduced into the UK.

There was nothing random about the location of Roman villages and towns. Even before construction would commence the Romans would carefully select where towns and villages would be sited. These were carefully planned to make optimum use of natural resources such as food, water, timber, stone etc. in a particular location. Security was also a key consideration where the Romans would ensure that the location and orientation of their towns and villages provided a secure environment as possible for those who would occupy these settlements. Early Roman towns were fortified around their perimeter with an earth ramp (embankment) and a wooden fence, however these were replaced in and around the 3rd century with much more robust stone walls, towers and gates.

Prior to the invasion of the UK, the Romans had spent hundreds of years building large, bold palaces, temples, bath houses and elaborate towns and cities throughout their ever expanding empire. The jewel in the crown was Rome itself which boasted buildings such as the Colosseum (completed circa 80 AD), the original St. Peter’s Basillica (completed circa 349 AD) and the Pantheon (completed circa 125 AD).  These types of buildings demonstrated that the Romans had exceptional architectural and engineering skills, the like of which had never been seen before.

Source: http://www.bible-history.com/maps/06-roman-empire.html
Larger buildings started to emerge in the UK where the Romans introduced limestone mortar which comprised of a mixture of lime, sand, gravel and water, to bind stones together to form walls, arches and vaults. Other mixtures were used to form mortar depending upon available raw materials in a particular location, however when set the completed wall/structure would be extremely strong and durable, which is evident from the many remaining Roman buildings and remains that still exist today.

Sanitation was also a priority as the Romans realised the importance of hygiene in reducing illness and death in the general population. Running water, drains and sewers were therefore considered as very important during the planning of Roman towns and cities. Gravity was a great ‘asset’ which the Romans would use to channel water from springs and other natural water courses, sometimes over considerable distances. This emphasises the earlier point that the Romans were meticulous in planning of the location of towns and cities to ensure that they would have a watercourse close by which was at a height (level) which would allow them to use gravity as a natural transporter of fresh water.

In my next article I will discuss Roman buildings in more depth and demonstrate how the Romans incorporated under floor heating into their palaces and bath houses, how the Romans included plastered and painted walls and how mosaics were used as status symbols by the rich and famous.  

Author: Gary O’Neill

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Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.

Monday, April 23, 2018

Buying a Property – Part 2 - The Real Value of a Building Survey



Never be tempted to cut corners when considering the purchase of a property because even if you think a building survey is expensive …… it often proves to be much more expensive not to have one

Source: Daily Mirror
In my last article I discussed the limitations of a survey that would be instructed by a mortgage lender (a mortgage valuation survey) and how a purchaser should not rely on this as means of assessing the condition of a building. This is because the primary purpose of this type of survey is to establish the value of a property and to be confident that in the event of any default on behalf of the borrower, that the lender can re-coup what they are owed. The objectives of a purchaser however are very different in that they want to be satisfied that the building they plan to buy, and often live in, is not concealing anything that they are not aware of. I say ‘not aware of’ as it is perfectly feasible and acceptable to proceed with the purchase of a building as long as you are fully aware of any potential issues/problems. Let’s face it, buildings, particularly older buildings are highly unlikely to be free from defects and in fact many of us will accept buildings with issues/problems at a lower price, as a way of trying to get a bargain, this is particularly true of property developers.

Not all of us are property developers and the vast amount of residential property transactions that take place each year are by members of the public who in many cases have little to no knowledge of buildings and therefore rely on professional guidance. It would therefore seem sensible, particularly due to the large investment involved that prospective purchasers commission a survey so that they can establish if there are any issues/problems with the building they are considering buying. However, you may be surprised to learn that the vast majority of purchasers choose to ignore this very important part of the purchase process. 

Source: RMA Surveyors
The Royal Institution of Chartered Surveyors (RICS) recently reported: ‘Results from an RICS’ survey of home buying consumers, released today, show that many homeowners who did not take out a home survey are left with a property they regret buying and an average of £5,750 in repair bills. The survey of 1,017 buyers across the UK found that consumers are clearly aware of the need for independent advice, with 94% of respondents agreeing it is important to commission a survey. However, nearly a third failed to do so. This means buyers are left ignorant of issues with the property, such as structural defects, dry and wet rot, subsidence and many other faults, only for these to become serious matters at a later date. The new homeowner may then be unable to afford, or may lose the desire, to fix the faults and may be left with a property they may no longer want to live in but are unable to sell to recoup their losses'. (Source: http://www.rics.org/)

Over a third of those surveyed failed to have an independent survey commissioned. We could speculate on why, however as 94% of respondents agreed that it was important to commission a survey, I think it is reasonable to discount ignorance as the primary reason for this. I suspect that cost may be a significant contributing factor, where many prospective purchasers see this as a cost they can do without and hope that they ‘get lucky’ and purchase a property with no issues/defects, that they were not aware of.  However, trying to save money at this point is a false economy. True, a comprehensive residential building survey may cost on average between £700 and £1000 (costs will vary depending upon the size and complexity of a dwelling and the survey selected), however, this is always money well spent. In fact, purchasers should be asking themselves if they can afford not to have a building survey undertaken rather than thinking about how much they will save by not having one done.

A level 3 Building Survey (see below), will provide a prospective purchaser with a comprehensive assessment of a dwelling and highlight not just significant issues, but anything that the Surveyor thinks is relevant. Armed with this information, the prospective purchaser may decide you try to negotiate the sale price with the seller (to reflect the findings of the survey) or maybe even decide to discontinue their interest and look for alternative properties. Either way, the information provides the purchaser with choices, where decisions can be made before contracts are signed rather than having to deal with the consequences when the property comes into their legal ownership. I am sure that in hindsight many of those who took part in the RICS research above would have regretted not spending £700 to £1000 on a Building Survey, as they ended up with an average repair bill of nearly £6000. Never be tempted to cut corners when considering the purchase of a property because even if you think a building survey is expensive you can see from above that it often proves to be much more expensive not to have one. On the flip side, the Building Survey may not identify any significant issues. Even in this scenario this represents good value for money as you now have piece of mind that the property you are considering is in reasonable condition and you are likely to avoid any nasty surprises. The lesson here is very simple: Always commission a Building Survey before exchanging contracts!

The information provided by RICS below summaries three different levels of survey that you may consider when purchasing a dwelling: RICS surveys are available to suit the particular circumstances of the client and the property:

Level 1 - Condition Report

Provides an objective overview of the condition of the property, highlighting areas of major concern without extensive detail. This option is ideal for buyers purchasing a modern house in good condition and for sellers and owners.

Level 2 - Home-buyer Report

Is most suitable for standard older and modern properties that are in an apparent reasonable condition. It provides a concise report with advice detailing any significant problems that could make a difference to the value of a property.

Level 3 - Building Survey

The ‘flagship’ service providing a detailed report on a property. It is particularly useful for older, larger or non-traditional properties, or one which is dilapidated and has been extensively altered or if the buyer is planning a major conversion or renovation. (Source: http://www.rics.org/)


Author: Gary O’Neill

Please feel free to share this article and other articles on this site with colleagues, friends and family who you think would be interested

Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog. 

Monday, April 9, 2018

Buying a Property – Part 1 – The Limitations of a Mortgage Lender’s 'Survey'



A Mortgage Lender’s 'survey' is for the lender only and should not be relied upon by a purchaser as a means of accurately assessing the condition of a property

Source: The Telegraph
Buying and selling of property can be one of the most daunting experiences of our lives. The complex process of dealing with Solicitors, Surveyors, Estate Agents, Mortgage Providers, Vendors (the person/s selling the property) and the like is something that the vast majority of us do not undertake on a regular basis, and is therefore something that often proves to be very stressful. First time buyers in particular will often feel overwhelmed by the whole process and will rely heavily on their advisors to guide them through the process. Once a decision has been made to purchase a property, buyers will work out their finances and decide how much they can afford to borrow and then try to secure a mortgage or at least a mortgage guarantee before beginning the process of house hunting. 

For most of us purchasing a property will be the largest financial investment we will make in our lives. It is therefore essential that we know exactly what we are buying before we exchange contracts because it is at this point that a property comes into your legal ownership. At exchange of contracts the law assumes that you have made all of your enquiries and that you are fully aware of what you were buying. If subsequently you find problems with the property, then these problems become your responsibility to deal with (unless you feel that you have been advised inappropriately and that you can prove this). It is therefore advisable to be as thorough as you can be to establish the full extent of any issues with a property before you exchange contracts. A range of different surveys can be carried out during the conveyance process for which the inexperienced, particularly first time buyers often do not understand the purpose or scope of the range of different surveys available. For clarity, this article will consider conveyance in respect of a residential dwelling.

Source: Stringinfo
Firstly, if you apply for a mortgage, a survey will be carried out by the lender on the property you are considering purchasing. Do not be misled by this survey. This survey is for the lender and not the purchaser. The purpose of the survey is for the lender to be satisfied that in the event that you default in some way on your repayments then in a ‘worst case scenario’ they will be able to sell the property and re-coup the money they have borrowed to you. This is all about the lender assessing their risk. These types of surveys are not intrusive and in fact they are extremely brief and in most cases are completed in approximately 20 to 30 minutes. The ‘Surveyor’ will make a brief internal inspection looking in the roof space if possible (usually from the top of a ladder). The inspection will also look for visible signs of timber decay or woodworm, and also consider the electrical installation amongst other things. This will be followed by an equally brief external inspection where the roof, chimneys, external walls etc will be inspected. As the Surveyor undertakes the inspection, a two or three page proforma (paper or electronic), mainly consisting of tick boxes will be completed.  The ‘report’ will then be returned to the lender and will indicate whether the property is worth the agreed sale price and also detail any urgent remedial works. It is from this report that the lender will decide whether they will borrow the agreed amount to the buyer or withhold a certain amount for any works the surveyor has identified as affecting the value of the property. I have a personal dislike for these types of surveys because in my opinion ‘surveyors’ are far too cautious in what they report. They often recommend timber and damp surveys and electrical inspections as standard without any real grounds for doing so, and often inaccurately report other issues. This is hardly surprising given the very brief inspection undertaken, however this cautious approach is more likely to be a result of the litigious world we now live in, where ‘surveyors’ provide ‘their own safety net’, and therefore try to reduce the risk of being sued. To a certain extent this is understandable, but this should never be at the expense of accurate reporting.

I few years ago I bought and sold a property. The surveyor for the lender of the prospective purchaser of my former house reported damp problems and an issue with the chimney. A timber and damp survey was recommended (by the surveyor) with a £1000 retention sum for repairs to the chimney. The prospective purchaser tried to use this to negotiate a reduction of the purchase price, however as a Chartered Building Surveyor I knew that this was completely inaccurate and unnecessary. I tried to challenge this, however as it was not my lender (it was the purchasers of my house), I continually hit a brick wall. My purchaser became unnecessarily nervous about buying a house which they now thought was riddled with damp and with a chimney that was about to collapse! In the end, and to ensure that we did not lose the sale, through gritted teeth, I agreed to a £500 reduction, even though this was completely unnecessary. I am sure that many reading this will have similar experiences, which I am also sure is one of the reasons why some property transactions fall through at the last minute, which is extremely frustrating.

This demonstrates that lenders rely on the advice of ‘surveyors’ who carry out such a brief inspection that it is almost laughable, who then recommend further inspections and remedial works that are often not necessary. Remember, a mortgage lender’s survey is for the lender only and should not be relied upon by a purchaser (mainly for the reasons stated above), as a means of accurately assessing the condition of a property. A much more comprehensive inspection is therefore required and I would recommend that a Building Surveyor is instructed to undertake a full, comprehensive survey of a property prior to contracts being exchanged. Although this will have a cost attached to it, you will often find that a building survey will prove to be extremely cost effective as it will highlight possible defects/issues which can either be used to negotiate the sale price, or possibly allow the buyer the choice of pulling out of the sale, before contracts are exchanged. This is something I will discuss in my next article.

Author: Gary O’Neill 

Please feel free to share this article and other articles on this site with colleagues, friends and family who you think would be interested 

Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.

Tuesday, April 3, 2018

Subsidence – Part 2 – Factors that contribute to subsidence



As with tree roots, a drainage system is buried therefore not obviously visible at the time of an inspection. It always amazes me how people tend to ignore the condition of the below ground drainage system when purchasing property and do not seem to see this as important

Source: Confused.com
In my last article I gave an example of the consequences of building subsidence, which can be extremely disruptive and expensive to deal with, however I also emphasised that the vast majority of subsidence damage is less serious and can be rectified reasonably easily. I also explained that to the average householder the mere mention of the word subsidence strikes fear and panic into them as there is a perception that subsidence damage is always serious. As you would expect and as I have mentioned many times before, if you are thinking of purchasing a property it is always advisable to have a professional, such as a Building Surveyor, inspect the building before you commit to buy. The Surveyor’s report will identify any issues that are present and inform you if any are serious. A Building Surveyor will also highlight factors that may contribute to subsidence in the future and not just focus on the here and now. There are a number of factors that could lead to subsidence and some examples are discussed below:

Clay SoilsTo support a building it is essential that the load bearing capacity of the ground is capable of supporting the dead load of the building (the building’s self weight) as well as any imposed load (furniture, fitting, people, snow etc.), once completed and occupied. The type of ground is essential to a building’s stability as this will determine the most appropriate as well as the depth of the foundation that should be used. When siting a building, clay soils are particularly problematic compared to most other types of soil because clay has the ability for significant volumetric change depending on how much water/moisture it contains at any particular time. When clay is wet it will swell and therefore expand, however when the ground starts to dry out all of this moisture is slowly removed and the clay will shrink. Think about this process happening with a building on it!  If the ground is constantly expanding and then shrinking, then it is inevitable that the weight of a building will eventually be affected by these changes and cause the building to move. Having said the above there is no reason why a building cannot be constructed on clay as long as this is established through ground investigations and appropriately catered for in the design. This may involve deeper foundations, as well as the inclusion of root barriers where trees and vegetation may be in close proximity to the building.

TreesWhilst inspecting a property, as well as focussing on the building itself I would always look very closely at the surrounding environment and in particular the size and location of trees. If not managed trees, and in particularly their roots have the ability to undermine foundations, damage drains and cause significant damage to a building. The problem with tree roots is that you often cannot see the extent of the root growth or proximity to the building because they are buried. This however does not mean that they should be ignored and where trees are deemed the pose a threat to a building then the services of a tree expert (Arboriculturist), should be called upon. This is necessary because different species of tree will exhibit different characteristic in terms of size, growth rate, root spread etc in addition to the advice that can be provided in respect of the condition of trees and any recommended remedial action.
Source: Absolute Plumbing and Drain Cleaning Services

Tree roots do a number of things when in the ground. Firstly, they take up large amounts of water. Given what has been discussed above in respect of clay soils you can easily see that in continued spells of warm weather and high temperatures that clay soil and tree roots are not a good combination and together this will significantly increase the potential for subsidence. Secondly, as the roots grow they have the ability to physically impact on soils, particularly the soft/granular types which can undermine their stability especially when they have a foundation and a building siting upon them.  Also, tree roots have the ability to damage below ground drainage.

DrainageAlthough it is possible to make a broad assessment of a drainage system during an inspection by lifting manhole/inspection chamber covers this is limited to a small number of access points only and does not identify the condition of the vast majority of the drainage system around a building. As with tree roots, a drainage system is buried therefore not obviously visible at the time of an inspection. It always amazes me how people tend to ignore the condition of the below ground drainage system when purchasing property and do not seem to see this as important. Even if there is no visible indication of any issues with a drainage system it is still worth considering a CCTV inspection of the system is carried out.

Below ground drainage is quite vulnerable and can become damaged in a number of ways. Ground movement, even subtle movement can result in drains becoming displaced and fractured, particularly around the joints. Tree roots can also damage below ground drains and find their way into the system. If this type of damage does occur then the surface and foul water which is usually heading toward a sewer, will actually start to discharge at the point/s where the drainage is affected. If left undetected for a period of time then vast amounts of foul and surface water can be discharged into the ground around a building, which over time can start to influence the stability of the soil, which could eventually lead to ground movement. The lesson here is always establish the condition of the below ground drainage system and deal with any problems quickly, before they become much more serious.

Adjacent Excavations A building could sit quite happily for many years on stable ground without any problems and will only be affected if for some reason the ground conditions change. One way this could happen is works being carried out in close proximity to a building that requires excavations. If excavations are carried out to a depth and distance that could undermine or influence the stability of another building then this can cause movement, sometimes, sudden movement. This should be considered in design where it may be necessary to provide temporary support. I have encountered this on numerous occasions where ground movement has been caused by a neighbour excavating (usually foundations) and usually through ignorance has not considered the stability of their neighbours building.

Leaking Rainwater Goods (gutters and downpipes) - Even simple repair and maintenance tasks, if left unattended over a period of time can introduce large amounts of water into the ground, which can affect the soil and undermine foundations which can cause ground movement. Rainwater gutter and downpipe repairs are usually inexpensive however this is one of the most common defects that a Surveyor will encounter when carrying out inspections. Repairs to rainwater goods are usually inexpensive however if they are ignored and left for longer periods of time the consequential damage can be extensive and therefore much more expensive. The lesson here is to deal with routine maintenance and repairs sooner or pay the costs later! 

This article provides a quick overview of some of the factors that could contribute to subsidence. The points raised are not exhaustive (there are others) and you will note that no attempt has been made to discuss mining subsidence, which is a subject in its own right, perhaps for a future post.  

Author: Gary O’Neill

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Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog. 

Friday, March 23, 2018

Subsidence – Part 1 – Not all it’s cracked up to be!



When you see cracking in a building it will not always be, in-fact is unlikely to be subsidence. This can only be established through a comprehensive building survey and detailed investigations

Source: Simply Business
As a Building Surveyor, when inspecting buildings I have learned over the years to be very cautious in the terminology I use in the presence of Clients because there are some words that just provoke panic. Take asbestos for example, or cracking or even subsidence. These words strike fear into many people mainly as a result of what they have seen in the news or read in the media. It is fair to say that sometimes these fears can be realised if any of the above examples are found to be present/occurring in a building, however in the vast majority of cases, these issues can be dealt with relatively easily. This is generally a result of a lack of real understanding, which is why it is always advisable to seek professional advice from a Building Surveyor or other relevant professionals.

When I first graduated from University I joined a Property Consultancy who’s main area of business was dealing with subsidence insurance claims as Loss Adjusters. My role was to visit site with a more experienced Structural Engineer, who would make an initial assessment, and then I would be required to manage the claim to a conclusion. This often involved crack monitoring to establish whether any movement was historic (had now stopped) or progressive (was still continuing). This was a crucial part of the process as it is pointless dealing with the effect of subsidence until movement has been stopped. On the occasions where movement was found to be progressive, it was sometimes first necessary to undertake substantial remedial work such as underpinning to stabilise the building. In these instances, the whole process could be lengthy and disruptive for the residents and in some cases required temporarily decanting of the occupants to alternative accommodation for the duration of the works. Most home insurance policies will cover subsidence risk and incorporate an excess payment in the region of £1000 (always check the wording of your policy because there can be variations). This demonstrates that the effects of subsidence can be disruptive and even though it may be covered by home insurance it can still be expensive.

Source: own
The above scenario provides an example of what can happen at one end of the scale, however as already stated the vast majority of subsidence claims I managed were dealt with quickly and with minimal disruption, many proving not to be subsidence at all. When undertaking building surveys, a Surveyor will not just identify where and why subsidence has occurred, but also look for indicators that may contribute to subsidence in the future. Before providing you with details of what I would look for during a survey (this will be provided in part 2 of the article), I think it is important to first understand exactly what subsidence actually is.

Building design should involve careful consideration of the type/load of the building, the type of foundation used and ground bearing capacity and nature of the ground, the height of the water table and so on. These types of investigations should help to ensure that once the building is complete and occupied that it does not move!  Subsidence however is not the same as settlement. Settlement usually occurs in new or relatively new buildings. As buildings are very heavy they cause the ground to compact, although this will usually stop after a short period of time.  Also, most buildings are constructed in a variety of materials, all of which need to settle and in addition will have different rates of shrinkage.  Subsidence occurs when for some reason the load bearing capacity of the ground that a building is placed upon is no longer capable of accommodating that load. The reasons for the change is the load bearing capacity is impacted and this can occur for many different reasons and in some cases, many years after the building was first completed. It is quite feasible for a building to sit quite happily on a piece of ground for many years and due to some of the influences discussed it part 2 of this article, it can start to move.

Cracking in buildings occurs for many different reasons so it is fundamentally important that anyone who undertakes inspections or gives advice in respect of cracking should not make rash judgements and should gather all of the evidence before arriving at a possible cause. In order to aid the inspector, which as stated previously, can be a Building Surveyor, it might be necessary to recommend other investigations such as geo-technical surveys to establish ground type, composition, contaminants etc., trial holes to establish foundation depths, CCTV inspection of the drainage system and possibly an arboricultural survey to give advice on any trees that may be an influencing factor. The choice of which investigations are needed will be decided once the inspector has made an initial assessment of the cracking.  Therefore, when you see cracking in a building it will not always be, in-fact is unlikely to be subsidence however, this can only be established through a comprehensive building survey and detailed investigations.

In Part 2 of this article I will discuss subsidence in more detail and provide information of the things a Building Surveyor will look at to identify when and how subsidence is occurring as well as indicators that may suggest that subsidence can occur in the future.


Author: Gary O’Neill

Please feel free to share this article and other articles on this site with colleagues, friends and family who you think would be interested

Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.