Posts Tagged ‘Basement’

How To Prevent Basement Waterproofing Failures

June 2025 Newsletter

Basement waterproofing failures cost the UK construction industry millions of pounds every year—not just in repairs, but in project delays, reputational damage, and client dissatisfaction. The most frustrating part? These failures are entirely preventable.

At MacLennan, we’ve spent decades refining our approach to waterproofing design, installation, and maintenance. In this post, we’ll explain how we prevent failures before they happen—and why our systems are trusted across the UK and beyond.

KC4 Lots Road Case Study road lift before after

KC4 KC4 Lots Road Case Study Road Case Study 17

May Newlsetter - 9 Partridge Walk - 10.05.2024 JH

✅ It All Starts with Smart Design

Most waterproofing failures can be traced back to one root cause: poor design. At MacLennan, we believe that good design is the foundation of waterproofing success. But we’re not just talking about detailing—we mean integrating the installation process, maintenance strategy, and repairability into the design from day one.

The British Standard and all major codes of practice are clear: waterproofing systems must be designed with repair and maintenance in mind. Yet, many systems are installed without any consideration for how they’ll be accessed or serviced once finishes are in place.

🧱 Why Type C Systems Are the Gold Standard

If your basement includes finishes, internal walls, or linings, then only a Type C cavity drain system can provide the level of repairability required for long-term performance.

Unlike other systems, Type C solutions are designed to manage water ingress by directing it to a controlled drainage system. But even these systems can fail—if they’re not properly maintained.

🔍 Inspection & Servicing: The MacLennan Difference

Most service providers focus on pump maintenance, but the real Achilles heel of a cavity drain system is the drainage channel. If this becomes blocked or compromised, the entire system is at risk. At MacLennan, we’ve solved this with:

We design and manufacture our own inspection ports, allowing directional camera access for full visibility.
We commission and inspect the system after finishes are installed—when many issues first appear.
We provide ongoing servicing through our dedicated in-house team, ensuring long-term performance.

📡 Remote Monitoring & Superyacht-Grade Reliability

We’ve taken it a step further with remote monitoring technology built into our systems. This allows us to track performance in real time and alert clients to potential issues before they become problems.

And when it comes to power reliability, we use state-of-the-art battery backups and inverters—the same systems trusted on ocean-going superyachts. These can even be upgraded to power essential services during outages.

🛠️ Servicing Is Not Optional—It’s Essential

You wouldn’t buy a car and never service it. A waterproofing system is no different. Regular maintenance is the key to preventing failures, and it should be built into the design from the start.

At MacLennan, we don’t just install systems—we design them for life.

💬 Want to Learn More?

We’re passionate about helping clients avoid costly waterproofing failures. If you’re planning a basement project or want to ensure your current system is protected for the long haul, get in touch with our team.

Inspector allows two-storey Kensington basement despite policy limiting basements to one storey

A planning inspector has granted planning permission on appeal for the construction of a building with a two-storey basement in west London, despite an adopted planning policy restricting basement developments to one storey.

Planning
UK
Europe

The inspector decided that allowing the proposed development would not be contrary to the underlying aims of the relevant policy, which sought to keep the construction impacts on neighbouring homes to acceptable levels.

Sugar Bay Hill Limited (SBH) had proposed to construct a four storey building with two basement levels at the vacant site of the former Kensington Tavern in west London. Commercial uses were proposed for the ground and below-ground levels, with 13 homes to be contained on the upper floors. The Royal Borough of Kensington and Chelsea decided to refuse permission for the scheme in January. The Borough had adopted a core strategy policy seeking to limit basement developments to 50% of the open part of any development site and for basements not to comprise more than one storey. In an appeal decision dated 18 September (9-page / 163 KB PDF), planning inspector Peter Rose said he attached significant weight to existing planning permissions for the site which allowed for the same amount of excavation at basement level as the appeal proposal. Rose noted that the only additional excavation that would take place under the appeal scheme would be a small lower basement area and that SBH had provided evidence that this additional excavation would add a maximum of 17 further days of work across a two-year construction period.

The inspector was satisfied that the proposed development “would not significantly harm the living conditions of neighbouring occupiers during the construction period” and was not, therefore, contrary to the underlying aims of the Borough’s basement development policy. Rose considered that the impacts of the development would be “outweighed by the overall net benefits of the scheme”. He noted that, compared to the proposals for the site that had already received permission, the appeal scheme would have greater benefits “with regard to housing and townscape” and offered more beneficial use on its upper floors thanks to the additional lower basement space for commercial uses. Planning expert Victoria Lindsay of Pinsent Masons, the law firm behind Out-Law.com said: “The construction impact on neighbouring residents and homes from basement development is a key concern for London boroughs at the moment, particularly in the Royal Borough of Kensington and Chelsea which is consulting at the moment on a draft Code of Construction Practice. The consultation draft Code of Construction Practice seeks to impose greater controls on hours of construction work and audible noise levels. The Borough is also looking at introducing an Article 4 direction in April 2016 to withdraw permitted development rights for basement development works.”

“Although this appeal decision grants planning permission for a two-storey basement contrary to adopted planning policy, it cannot be taken as a precedent for two-storey basements in the future across the Borough,” said Lindsay. “The inspector clearly placed a great deal of weight on the extant planning permissions for the site permitting the same amount of basement excavation as the appeal proposal and decided that there would be no significant additional construction impact over a two year construction period. Therefore, the purpose of the policy, seeking to keep construction impacts on neighbouring homes to acceptable levels has not been hindered.”

“This appeal decision helps to focus minds on how basement policies should be applied and properly interpreted,” said Marcus Bate, another planning expert at Pinsent Masons. “The size of a proposed basement can be given too much weight in isolation. What really matters is whether the impact on neighbouring living conditions is acceptable. The Inspector rightly recognised that this was the only way to reach a proper balanced judgment in the case.”

Ian MacLennan
CSSW CSRT

MacLennan & John Newton training

MacLennan recently spent a day with our waterproofing products supplier, John Newton. Consistent training like this helps both of us progress and stay up to date within our industry.