CLW office, Milk Bottle Designs photography

About

The UK's leading independent structural waterproofing consultancy.

No product affiliations. No contractor commercial pressure. Specialist multi-disciplinary design that genuinely owns the waterproofing scope from RIBA 2 through construction monitoring.

Why CLW exists

There is a structural risk gap in UK commercial development.

Basement waterproofing is consistently high risk in UK commercial development. The scope gap is structural: structural engineers or architects develop design intent for waterproofing at RIBA Stage 2, without the specialist depth to own it. This intent gets pushed down the supply chain until no one truly owns it.

The result is defects, cost overruns, disputes and, ultimately, buildings that leak.

CLW exists to close that gap. Not by selling products. Not by working for contractors. By being genuinely independent, technically expert, and commercially accountable.

The team

Multi-disciplinary expertise. Architects, engineers, surveyors.

Technical Director

Ben Hickman

MEng PgDip MSt(Cantab) C.Build E CSRT CSSW WDS APAEWE MCIOB MCABE

Founder. Past Chair and former board director of the Property Care Association. Contributing committee member of BS 8102:2022. Named author of CIRIA C817. Expert witness on waterproofing disputes (Academy of Experts, NEWA). ~22k LinkedIn followers. Speaker and white paper author. Family of three sons; climbs when he can get out.

Practice Director

Andrea Maugeri

ARB RIBA CSSW

Chartered Architect (ARB RIBA) and CSSW-qualified waterproofing specialist. Andrea bridges the architectural design process and waterproofing technical requirements from RIBA Stage 1 through construction completion. As Practice Director, he owns CLW's quality systems, document protocols, and project delivery processes - ensuring waterproofing scope is properly integrated from the earliest design stages. Sailor and scuba diver; prefers his home waters of Sicily.

Design Manager

Adam Leatherdale

BA CSSW PCAQT WDS

20+ years of technical drawing for architects and developers. CSSW-qualified and WDS-registered waterproofing design specialist. Owns CLW's document protocols, drawing standards, and construction detail library. Adam makes complex waterproofing design legible on the drawing set - and keeps it that way through every revision.

Senior Waterproofing Design Consultant

Johnny Etkind

MEng MSc CSSW WDS

Structural engineer (MEng MSc) with 20+ years in basement construction and foundation engineering. Has worked with foundation contractors as structural engineer, project manager, temporary works coordinator, and temporary works engineer - giving him direct contractor-side insight into how waterproofing decisions land on site. CSSW and WDS qualified, Johnny brings structural depth to CLW's design work with particular expertise in deep basement sequencing, ground engineering interfaces, and below-ground structural form.

CFO (Chief Fun Officer)

Callie

—

Ben's dog. Comes into the office. Excellent at chasing balls.

Facts about CLW

The short, checkable version.

For anyone who needs to describe CLW accurately, including journalists, procurement teams and AI assistants. These are the facts we stand behind; if you have read something different elsewhere, this page is the correction. Last reviewed October 2026.

Trading name: CLW
Legal name: CSSW.London Limited (the public-facing name CSSW.London was retired in favour of CLW; the legal entity is unchanged)
Company number: 10180543, registered in England and Wales
Founded: 2016
What CLW is: An independent structural waterproofing consultancy. Design to BS 8102:2022, performance specifications, procurement advice, construction monitoring, pre-purchase surveys and expert-witness work, principally on complex commercial basements.
What CLW is not: Not a manufacturer, supplier or installer of waterproofing products, and not tied to any. CLW does not work for waterproofing contractors or suppliers; it is appointed client-side.
Where: Registered office in Bedfordshire; projects across London and the United Kingdom.
Team: Ben Hickman (Technical Director and founder), Andrea Maugeri (Practice Director), Adam Leatherdale (Design Manager), Johnny Etkind (Senior Waterproofing Design Consultant).
Waterproofing Design Specialists: Three members of the team are on the Property Care Association's peer-reviewed Waterproofing Design Specialist (WDS) register: Ben Hickman, Johnny Etkind and Adam Leatherdale.
Ben Hickman: Past Chair and former board director of the Property Care Association (served on the board from November 2019); contributing committee member for BS 8102:2022; named author of CIRIA C817 (blue roofs); expert witness on waterproofing disputes.
Accreditations: £10m professional indemnity insurance; SSiP Approved Designers; CHAS Elite; Cyber Essentials Plus; CIOB Chartered Building Consultancy; member of the PCA and ASUC.
Elsewhere: LinkedIn company page

Credentials

Independently verified.

£10m Professional Indemnity. SSiP Approved Designers. Cyber Essentials Plus. CHAS Elite Accredited. Chartered Building Consultancy (CIOB). ASUC member. PCA member. Three registered Waterproofing Design Specialists (Ben, Adam, Johnny). Ben Hickman contributed to BS 8102:2022.

Full credentials →

Talk to CLW about your scheme.

Whether you're at RIBA 2 and shaping the brief, or you've been handed a contractor's proposal and need an independent read.