Introduction

BS 8102:2022 – Protection of Below Ground Structures Against Water Ingress offers guidance on basement waterproofing in the UK.  A key requirement of the standard is the need for the waterproofing system to be repairable in the event of failure. Defects in the waterproofing system are anticipated, and remedial measures should be feasible to ensure that the system remains cost-effective to remediate should water ingress occur. Most modern basements feature blockwork inner skins or framing systems that prevent access to the retaining wall, making repairs to the substrate more complicated if water ingress occurs while the building is occupied.  Similarly, the basement floor is often finished with insulation and screed, preventing access to the substrate.  Although these issues make repair more difficult, it is not impossible. When finishes are employed inside the basement, it is often claimed that the only fully compliant system is a Type C cavity drainage system. Parts of this system (ie the drainage channels and chambers) can be inspected and flushed at intervals throughout the structure’s lifespan. However, the cavity drain sheet has the same issue of access as other types of waterproofing. If this blocks, it will be difficult to repair. In any event, should we design for failure by specifying Type C waterproofing or aim to get it right with other types of waterproofing the first time?

The Problem with a ‘Catch-All’ Approach

The problem with assuming defects and relying on a catch-all solution, such as a cavity drainage system, is that it creates a self-perpetuating cycle. Contractors and designers may believe that primary waterproofing measures (external membranes and watertight concrete), can be constructed with defects, knowing that the secondary system will address any issues. Instead of properly implementing the primary systems, this overreliance on backup solutions ultimately leads to defects in the primary systems.  The approach may lead to poor workmanship and inherent risks associated with the durability of the structure, resistance to ground gas ingress, resistance to contaminated groundwater and air tightness.

Addressing repairability is often seen by the designer as a tick-box exercise, particularly when external land drains are used to satisfy the requirement. The rationale is that, in the event of a future leak, rodding an external land drain will relieve hydrostatic pressure from behind the wall and prevent further water ingress. This approach is flawed due to practical challenges associated with rodding deep land drains, which are often more than 4 metres below ground in a single-storey basement. In sloped developments, the land drain behind the retaining wall is situated beneath the ground floor slab, making access unfeasible. Land drains are unsuitable for boundary line projects, such as inner-city developments, because of the type of construction using piled or sheet pile retaining walls and the lack of access behind the retaining wall. Locally draining the water table can also affect the stability of the surrounding strata and structures. Often, basements leak due to issues with the “termination detail” at the top of the retaining wall, which the land drain at the foot of the wall does not impact. The standard placement of a land drain will prevent hydrostatic pressure against defects located in the walls, but not within the slab without a drainage layer. Land drainage often gives the client a false sense of security rather than a truly maintainable system. It is also not acceptable to discharge land drains into sewers.

A Better Solution: A Risk-Focused Design and Clear Responsibilities

When building a new basement, a sensible approach would focus on preventing water ingress into the reinforced concrete structure, achieved through a combination of Type A (external membrane) and Type B (watertight concrete) waterproofing. Utilising these options protects the concrete and steel from water ingress, resulting in increased durability. Any leaking construction joints, cracks, or other defects should be injected or repaired prior to the installation of the building finishes. Where the water table is low, a flood test could be performed to reveal defects that may result in future water ingress from burst water mains, heavy rainfall events, or any other changes in the external environment.

Proper classification of the water table is essential for effective structural waterproofing design. Current industry practice includes design to a worst-case scenario (assuming the water table is at ground level), often leading to over- classification of certain aspects of, or the entire basement project, as high risk, which dilutes the focus on the actual high-risk areas of the construction. A more realistic water table assessment would allow contractors to prioritise critical areas that require the most attention. This assessment is best carried out by geologists or geotechnical engineers with a good understanding of the factors that can affect water levels in monitoring wells and whether it represents a free groundwater body.

The risk assessment shouldn’t only rely on the highest water level recorded in a monitoring well or assume a worst-case scenario of the water table at ground level. It requires an understanding of factors such as groundwater flow and the effects of artesian water in confined aquifers, as well as the risks posed to basements, for instance, if the confining layer above artesian water is reduced in thickness. If a basement is built into cohesive soil, such as London Clay, it should not automatically be categorised as “high risk”; in certain circumstances, the clay can protect the basement from water ingress.

There is a tendency in our industry to overdesign waterproofing systems on lower-risk projects, primarily driven by manufacturers and suppliers. This not only increases costs but also has a considerable environmental impact. Each additional layer of waterproofing requires manufacturing, transportation, and installation, all of which contribute to the project’s overall carbon footprint. A more representative risk assessment can result in a more appropriate design, ensuring that only the essential materials are specified.

The risk associated with the basement should be assigned using a well-thought-out conceptual site model that considers the high-risk aspects of the structure, including:

• Geology and groundwater conditions.
• What is the actual risk of water main failure, etc (eg is there a large high-pressure water main near the building, or is it just a local supply pipe).
• Joints between liner walls and capping beams.
• Tie bolt holes.
• Terminations into DPC details.
• Pipe penetrations.
• Continuity of waterbars.
• Below-ground isolation/expansion joints.

Repairability should apply to all parts of any waterproofing system and should not mean designing for failure; rather, there ought to be an emphasis on a higher standard of workmanship and proactive risk management. Often, the most stringent QA procedures are implemented at the project’s outset but tend to wane during the higher-risk elements later in the process (such as pipe penetrations and terminations into DPC detailing). A quality assurance plan is recommended for inclusion in the waterproofing design report and should be completed by the contractor throughout the construction process, documenting:

• the delivery, recording, and storage of materials on-site,
• the suitability of surface preparation,
• installation record sheets,
• photographic records,
• inspection and comments by system manufacturers.

A common misconception among contractors is that supplier site visits are formal sign-offs for waterproofing installations rather than advisory inspections. This misunderstanding often leads to a careless approach, with installers assuming that once the supplier has visited, they take on the responsibility for the installation. In reality, supplier warranties typically cover material defects only, not poor workmanship. While suppliers offer guidance, they do not usually assume responsibility for the installation. Responsibilities for each aspect of the waterproofing installation should be clearly outlined in the quality assurance plan to avoid miscommunication.

The application of guidance in BS 8102:2022 on repairability does not provide the client with the most effective solution; instead, it offers contractors a false sense of security that the system will not fail within the warranty period. A sensible design, paired with increased focus on the high-risk aspects of the project and a realistic risk classification, would enhance the structure’s durability and reduce the costly maintenance and discharge permit expenses associated with Type C waterproofing systems.

The long-term cost difference between a well-designed, properly installed waterproofing system and one that depends on the maintenance and replacement of pumps is substantial for the client but is often overlooked at the design stage. A Type C system requires annual inspection, and the pumps need replacing approximately every ten years. These costs accumulate to a significant fee over the design lifespan of the structure. Frequently, the maintenance of the Type C system is neglected, and water ingress will occur if the pumps fail or the system becomes blocked with free lime or other deposits. If discharging to a sewer, there are annual discharge permit costs.

Conclusion

Compliance with BS 8102 should not compromise good design practices and high standards of workmanship. Accurate risk assessments, designs that prioritise the protection of the structure for the design life with minimal maintenance, and waterproofing installations that prioritise quality should be the focus of our industry, rather than blanket worst-case approaches based on assumptions of failure.

Introduction

BS 8102:2022 – Protection of Below Ground Structures Against Water Ingress offers guidance on basement waterproofing in the UK.  A key requirement of the standard is the need for the waterproofing system to be repairable in the event of failure. Defects in the waterproofing system are anticipated, and remedial measures should be feasible to ensure that the system remains cost-effective to remediate should water ingress occur. Most modern basements feature blockwork inner skins or framing systems that prevent access to the retaining wall, making repairs to the substrate more complicated if water ingress occurs while the building is occupied.  Similarly, the basement floor is often finished with insulation and screed, preventing access to the substrate.  Although these issues make repair more difficult, it is not impossible. When finishes are employed inside the basement, it is often claimed that the only fully compliant system is a Type C cavity drainage system. Parts of this system (ie the drainage channels and chambers) can be inspected and flushed at intervals throughout the structure’s lifespan. However, the cavity drain sheet has the same issue of access as other types of waterproofing. If this blocks, it will be difficult to repair. In any event, should we design for failure by specifying Type C waterproofing or aim to get it right with other types of waterproofing the first time?

Introduction

BS 8102:2022 – Protection of Below Ground Structures Against Water Ingress offers guidance on basement waterproofing in the UK.  A key requirement of the standard is the need for the waterproofing system to be repairable in the event of failure. Defects in the waterproofing system are anticipated, and remedial measures should be feasible to ensure that the system remains cost-effective to remediate should water ingress occur. Most modern basements feature blockwork inner skins or framing systems that prevent access to the retaining wall, making repairs to the substrate more complicated if water ingress occurs while the building is occupied.  Similarly, the basement floor is often finished with insulation and screed, preventing access to the substrate.  Although these issues make repair more difficult, it is not impossible. When finishes are employed inside the basement, it is often claimed that the only fully compliant system is a Type C cavity drainage system. Parts of this system (ie the drainage channels and chambers) can be inspected and flushed at intervals throughout the structure’s lifespan. However, the cavity drain sheet has the same issue of access as other types of waterproofing. If this blocks, it will be difficult to repair. In any event, should we design for failure by specifying Type C waterproofing or aim to get it right with other types of waterproofing the first time?

Introduction

BS 8102:2022 – Protection of Below Ground Structures Against Water Ingress offers guidance on basement waterproofing in the UK.  A key requirement of the standard is the need for the waterproofing system to be repairable in the event of failure. Defects in the waterproofing system are anticipated, and remedial measures should be feasible to ensure that the system remains cost-effective to remediate should water ingress occur. Most modern basements feature blockwork inner skins or framing systems that prevent access to the retaining wall, making repairs to the substrate more complicated if water ingress occurs while the building is occupied.  Similarly, the basement floor is often finished with insulation and screed, preventing access to the substrate.  Although these issues make repair more difficult, it is not impossible. When finishes are employed inside the basement, it is often claimed that the only fully compliant system is a Type C cavity drainage system. Parts of this system (ie the drainage channels and chambers) can be inspected and flushed at intervals throughout the structure’s lifespan. However, the cavity drain sheet has the same issue of access as other types of waterproofing. If this blocks, it will be difficult to repair. In any event, should we design for failure by specifying Type C waterproofing or aim to get it right with other types of waterproofing the first time?

Are there other ways to assess infiltration that have fewer health and safety risks and a lower environmental impact? Afterall, determining infiltration rates is more than pouring water into a hole.

Health and safety is paramount, where risks can be removed, it is our duty to do so. Heavy plant digging holes is a high-risk activity.BRE365 tests are intensive, using heavy machinery and virgin aggregate. They can take significant time to complete, especially in lower permeability geology, potentially slowing progress on projects.

Addressing concerns from the BRE365 test method, we are looking at how infiltration is assessed.

Driving the industry forward in a pragmatic way, we think it’s vital to question and review set guidance and push for updated testing to be considered.

In the latest document with Susdrain, Steve Wilson and Jacqueline Diaz-Nieto discuss the alternatives to BRE 365 infiltration in collaboration with Susdrain.

Read the full article here: infiltration rates for SuDS: is it time to ditch BRE 365 tests?

If you would like to find out more about alternatives to BRE 365 infiltration and the options EPG can provide, please speak to Leo Phillips, Head of Commercial and he’ll be able to help – leo.phillips@epg-ltd.co.uk

Offering unrivalled expertise across a range of environmental engineering disciplines, the Environmental Protection Group (EPG) is excited to announce its move to a new office location at The Innovation Centre Sci-Tech in Daresbury, Warrington.

The move comes as part of the company’s continued growth and commitment to enhancing productivity, collaboration, and the overall work environment for its team. Other EPG colleagues remain based at a combination of Bingley and Basildon offices, as well as remotely.

“Our new office offers a spacious and modern environment, equipped with facilities and grounds to support our team’s overall wellbeing and puts us alongside some fabulous, like-minded businesses” said Phil Williams, Director of EPG.

“This relocation marks a significant milestone in our journey as we expand our business and continue to provide exceptional service to our clients.”

As part of their ambitious growth plans, EPG has appointed Damian Watkin as an Associate in the geoenvironmental team. Damian comes with a wealth of industry knowledge and will be managing the delivery of geoenvironmental investigation and assessment projects. He will be maintaining key client relationships and mentoring the team, to continue to bring an unparalleled service offering in the industry.

EPG looks forward to continued growth and building stronger relationships with clients and partners in this new, dynamic environment.

SuDS in schools – is conventional drainage alone a thing of the past?

Extreme flooding across the UK is something that people are experiencing with increasing regularity, and schools and education authorities are looking for cost effective, long-term solutions which can keep children safe, and avoid closures from these weather events.

Sustainable drainage systems, commonly known as SuDS, are designed to slow the flow of water and mimic nature’s defences.  Unlike conventional drainage which directs water underground, SuDS keep the water on the surface and manage water where it falls.  Future generations will need to look practically at how water is managed in urban and rural environments, as conventional drainage is creaking under the pressure of increased rainfall associated with climate change and increased urbanisation. SuDS address these issues through blue green design and provide a positive solution in combating climate change.

From recent storm events, schools have been forced to close due to extreme conditions and with having aging infrastructure in place to combat the quantity of water on site.

Funding is available to schools through the DfE website to encourage retrofit SuDS on sites which is recognised as a highly effective way of reducing surface water flooding following the PIT review and Flood and Water Management Act 2010. Natural disasters, flooding and the climate is part of the school curriculum and schools are taking responsibility for their own water management.

What are the benefits of SuDS in schools?

• Landscape legibility and enhance education opportunities

This is where pupils learn to read the landscape they’re observing and understand the flow of water.  SuDS bring the curriculum to life by bringing water and biodiversity into the centre of the school and educate pupils so that they have a clear understanding of where the water is meant to go, banishing any misconceptions and raising awareness within the whole community.

• Holistic sustainability

Following the management train approach as demonstrated in the SuDS manual promotes the incorporation of source control techniques to collect, treat, store and control runoff prior to discharge, and improve the biodiversity in the area.  By having a space for plants, this creates a nicer environment and helps bring down the temperature in the area.  Planters and rain gardens bring the water cycle to life, as a reservoir is available for the plants to drink, and with the correct soil allows the plants to access water without the need for hosepipes, saving costs as well as creating a sustainable environment.

Blue green approaches encourage evapotranspiration and mitigates against the urban heat island effect.

• Maintenance

When water is kept on the surface, we know when it is at its capacity. The visible nature of SuDS means that it is apparent when it needs an outlet, avoiding unexpected problems.  Maintaining SuDS is routine work and involves clearing leaves, pruning plants and is a great way to involving pupils. It is hugely beneficial and educational, and less costly to manage.

Phil Williams, Director at the Environmental Protection Group stated, “We have been working alongside schools for over 15 years implementing sustainable drainage designs across the UK, both new and retrofit.  The joy it brings to the community is something we’re always thrilled to see, and if we can continue to mitigate the impact of flooding with natural flood management, we should start to see positive changes for our environment.”

The technicalities – how using the right suppliers gets you the right results

Simpler stakeholder engagement

Stakeholder engagement and good consultation is the key to avoiding misconceptions and banishing myths surrounding SuDS.  The opportunity to incorporate SuDS in a project should be met with excitement. For planners, architects and engineers, it is their job to communicate and showcase how this vision will become a reality. Dealing with one stakeholder allows for a smooth, simple scheme delivery.

Collaboration

Co-design between landscape architects, SuDS designers, engineers and the schools is important to ensure engagement in the project and understanding.  For the very best results, landscape architects need to work in harmony with engineers and then the contractors.  With landscape architects working on the aesthetics and visuals alongside the school, the engineers are left to determine the flow rates and quantification of the impact the SuDS features will have for funders and authorities.

Safety

Safety considerations for any project is vital, however it’s important to recognise that for most of the time, SuDS feature will have no water in them, and when raining, only hold a small amount of water, usually between 100ml-300ml. This means no danger for pupils and simply becomes a learning aid.  SuDS also work at removing pollutants and sediment from a water flow, all powered by nature.

Take a look at the video below to see how a school in Estcourt School in Hull put this into practice.

The Environmental Protection Group (EPG) co-authored the SuDS manual and is passionate about designing projects which can enrich people’s lives and their surrounding environments for the future.  The introduction of SuDS in an area brings enhanced biodiversity, amenity, improves water quality and reduces water quantity. Conventional drainage can’t provide amenity or biodiversity to any area so sustainable measures should be implemented where possible.

Let’s design with nature in mind.

SuDS in schools – is conventional drainage alone a thing of the past?

Extreme flooding across the UK is something that people are experiencing with increasing regularity, and schools and education authorities are looking for cost effective, long-term solutions which can keep children safe, and avoid closures from these weather events.

Sustainable drainage systems, commonly known as SuDS, are designed to slow the flow of water and mimic nature’s defences.  Unlike conventional drainage which directs water underground, SuDS keep the water on the surface and manage water where it falls.  Future generations will need to look practically at how water is managed in urban and rural environments, as conventional drainage is creaking under the pressure of increased rainfall associated with climate change and increased urbanisation. SuDS address these issues through blue green design and provide a positive solution in combating climate change.

From recent storm events, schools have been forced to close due to extreme conditions and with having aging infrastructure in place to combat the quantity of water on site.

Funding is available to schools through the DfE website to encourage retrofit SuDS on sites which is recognised as a highly effective way of reducing surface water flooding following the PIT review and Flood and Water Management Act 2010. Natural disasters, flooding and the climate is part of the school curriculum and schools are taking responsibility for their own water management.

What are the benefits of SuDS in schools?

• Landscape legibility and enhance education opportunities

This is where pupils learn to read the landscape they’re observing and understand the flow of water.  SuDS bring the curriculum to life by bringing water and biodiversity into the centre of the school and educate pupils so that they have a clear understanding of where the water is meant to go, banishing any misconceptions and raising awareness within the whole community.

• Holistic sustainability

Following the management train approach as demonstrated in the SuDS manual promotes the incorporation of source control techniques to collect, treat, store and control runoff prior to discharge, and improve the biodiversity in the area.  By having a space for plants, this creates a nicer environment and helps bring down the temperature in the area.  Planters and rain gardens bring the water cycle to life, as a reservoir is available for the plants to drink, and with the correct soil allows the plants to access water without the need for hosepipes, saving costs as well as creating a sustainable environment.

Blue green approaches encourage evapotranspiration and mitigates against the urban heat island effect.

• Maintenance

When water is kept on the surface, we know when it is at its capacity. The visible nature of SuDS means that it is apparent when it needs an outlet, avoiding unexpected problems.  Maintaining SuDS is routine work and involves clearing leaves, pruning plants and is a great way to involving pupils. It is hugely beneficial and educational, and less costly to manage.

Phil Williams, Director at the Environmental Protection Group stated, “We have been working alongside schools for over 15 years implementing sustainable drainage designs across the UK, both new and retrofit.  The joy it brings to the community is something we’re always thrilled to see, and if we can continue to mitigate the impact of flooding with natural flood management, we should start to see positive changes for our environment.”

The technicalities – how using the right suppliers gets you the right results

Simpler stakeholder engagement

Stakeholder engagement and good consultation is the key to avoiding misconceptions and banishing myths surrounding SuDS.  The opportunity to incorporate SuDS in a project should be met with excitement. For planners, architects and engineers, it is their job to communicate and showcase how this vision will become a reality. Dealing with one stakeholder allows for a smooth, simple scheme delivery.

Collaboration

Co-design between landscape architects, SuDS designers, engineers and the schools is important to ensure engagement in the project and understanding.  For the very best results, landscape architects need to work in harmony with engineers and then the contractors.  With landscape architects working on the aesthetics and visuals alongside the school, the engineers are left to determine the flow rates and quantification of the impact the SuDS features will have for funders and authorities.

Safety

Safety considerations for any project is vital, however it’s important to recognise that for most of the time, SuDS feature will have no water in them, and when raining, only hold a small amount of water, usually between 100ml-300ml. This means no danger for pupils and simply becomes a learning aid.  SuDS also work at removing pollutants and sediment from a water flow, all powered by nature.

Take a look at the video below to see how a school in Estcourt School in Hull put this into practice.

The Environmental Protection Group (EPG) co-authored the SuDS manual and is passionate about designing projects which can enrich people’s lives and their surrounding environments for the future.  The introduction of SuDS in an area brings enhanced biodiversity, amenity, improves water quality and reduces water quantity. Conventional drainage can’t provide amenity or biodiversity to any area so sustainable measures should be implemented where possible.

Let’s design with nature in mind.

Greening Brownfields: Unlocking the potential for SuDS on brownfield land

This International Women’s Day we are celebrating the inspirational women that contribute to our success. Leading the way are the heads of our Water and Geoenvironmental teams, Jacqueline Diaz-Nieto and Amy Juden, who share their collaborative thoughts on the potential for SuDS to be used on brownfield sites.

With a housing crisis that shows no sign of slowing, coupled with a desire to conserve our dwindling green spaces, there is a renewed push to find development space on brownfield land. The regulative landscape will soon see the introduction of Schedule 3 which means the industry will need to consider using sustainable drainage systems (SuDS) on every development site.

Using sustainable drainage systems on brownfield land brings advantages. Sustainable drainage systems can be designed to complement the ground conditions and constraints and bring multiple additional benefits to a project; greening brownfield sites. The wide-ranging positives of this approach shouldn’t be underestimated.

Schedule 3 requires designers to consider SuDS within a hierarchy that prioritises discharging surface water to ground, and with SuDS also serving a dual purpose of satisfying the Biodiversity Net Gain (BNG) requirements, making SuDS work on brownfield sites makes financial and environmental sense and will ensure compliance with new requirements.

Resistance may exist against infiltration drainage on potentially contaminated sites. It is true that infiltrating water has the potential to mobilise soil contaminants and subsequently pollute rivers and groundwater, however, depending on the contaminants and their leachability (mobility in water), infiltration could be acceptable if properly assessed and designed. This is especially true for diffuse infiltration limited to pre-development rates, which is likely to be suitable on all but the most severely contaminated development sites. Concentrated soak-away drainage might not be suitable through made ground or contaminated materials, but it may still be possible to locate these to discharge at slightly greater depth into natural ground, or on a less contaminated part of the site. Even on development sites where leachable contamination has been identified it may be possible to plan the remediation strategy such that these soils are relocated to less sensitive areas or capped by hard surfacing.

Even on highly contaminated sites, SuDS designed not to infiltrate can bring significant advantages, and shouldn’t be ruled out. Waste disposal costs for contaminated soil, particularly if classed as hazardous can be a significant cost to development. Keeping drainage systems shallow and designing out deep drainage and large attenuation tanks can reduce the associated excavation and removal costs, particularly relevant for contaminated ground. Shallow water storage used in SuDS could include gravel layers or geocellular crates under permeable paving or lined landscaping features. These solutions can come into their own for redevelopment of former landfill sites, where not only is excavation and soil disposal costly, it may also come with specific environmental permitting requirements. With wait times for some bespoke environmental permit decisions extending over 24 months, this is not an appealing option for developers or contractors, and SuDS may provide the solution!

SuDS champions often talk about the four pillars of good SuDS being the design for quantity, quality, amenity and biodiversity. Whilst often overlooked by traditional drainage designers, the potential amenity and biodiversity benefits of SuDS on brownfield land is huge and can strengthen the case for making SuDS work on brownfield land. Well-designed SuDS not only provide the hydraulic attenuation requirements to achieve greenfield runoff rates, reducing the risk of flooding downstream, but vegetated SuDS (with the shallow attenuation below ground) provide much-desired urban greening, they also bring a myriad of other social and environmental benefits.

SuDS sells! SuDS provide multiple landscape and biodiversity benefits, making new developments an attractive place to be as well as providing amenity and social value along with the economic advantages of rejuvenating an area. Together these factors make developments much more desirable. This is particularly pertinent when a site was previously derelict, unused, or unloved. Getting SuDS onto your brownfield sites is literally turning brown to green!

Success in these designs depends on understanding the ground model, specific constraints in the ground from previous uses, levels of contamination and the pathways for contaminant migration. Drainage designs for brownfield sites therefore benefit massively from the input of geoenvironmental professionals from the start. Experts who understand all aspects and can advise SuDS designers on safe working depths for the SuDS attenuation layer and specify from the start whether leaky SuDS can be designed, busting the popular myth that SuDS on brownfield sites must be tanked.

At EPG, our combined skills and experience in drainage design, ground conditions and land contamination allows us to unlock the potential benefits of SuDS on brownfield sites and provide clients with a one-stop shop.

Our dynamic team is changing the narrative around holistic environmental designs for challenging sites. Don’t believe anyone who tells you that you can’t infiltrate on brownfield land. Challenge any design that includes a deep-dig through contaminated ground for a large attenuation tank. Get in touch with EPG to see if we can do better and provide you with a more cost-effective, greener design using our innovative approach.

Imagine a simple remortgaging conversation revealing that your house has no financial value. This was the harsh reality for one of thirteen residents in Bradford, who discovered that the developer not adhering to planning conditions had resulted in his home receiving a zero valuation on remortgaging. 

The plight of the residents was shared in October 2020, on the BBC programme ‘Rip off Britain’. Details emerged that  gas membranes had not been installed and verified as required by the planning conditions, and the developers had since ceased trading, leaving residents stranded and distraught.  

With a wealth of experience in risk assessments and land remediation, EPG stepped in to examine the cases in detail. With an offer to investigate, free of charge, our Technical Director Steve Wilson sat down with some of the residents to discuss potential ways to resolve the problem. It became apparent that other planning conditions, relating to soakaways in the back gardens and an access road, had also not been complied with.   

The homes are located adjacent to a former landfill site which is also an area of former coal mine workings. However, this does not automatically mean that there is a risk of gas ingress into the buildings. Using existing information, EPG built up a detailed conceptual site model (CSM). The CSM is a vital part of any gas risk assessment and crucially, the part where extra time and effort pays dividends.  

It took over a week to drill down into the information and compile the model, which demonstrated that the risk of gas emissions was very low and gas membranes were not required. Furthermore, there was no need for further site investigation or gas monitoring to support this conclusion.  

EPG can provide this service for developers, and the cost of the desk study is usually far less than the cost savings achieved by removing the need for gas protection or gas monitoring at the preliminary risk assessment stage. Even where gas monitoring is required, we can often reduce or completely remove the need for gas protection systems.   

EPG also provided a revised specification and design for soakaways in the back gardens, with clients Alderburgh and JUTA (UK) kindly supplying the soakaway boxes and geotextile surround at no cost to the residents.  

The final piece in the jigsaw was to meet with the Highway Authority and agree that the access road could remain unadopted (private), avoiding the need for remedial works to bring it up to highway standards. There was a small cross over strip at the entrance already owned by the Highway Authority and EPG designed and specified some simple works to resolve the issue.  

EPG is part of a wider consultancy – STRI Group, and working alongside one of their senior planners, James Podesta, were able to submit a planning application to remove/vary the planning conditions to formalise amendments, and this was approved last year.  

The work put into place will allow the homeowners to proceed as normal and we wish them all the best for the future.