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En Masse Design Limited

Chartered Building Services Consulting Engineers for Mechanical, Environmental, Electrical, Plumbing & Infrastructure Services

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About Us

Founded in October 2001 and based in Surrey, En Masse Design are Chartered Building Services Consulting Engineers who provide a specialised multi-discipline Mechanical, Electrical and Plumbing design service for all types of new and existing building projects.

We have worked successfully with Blue Chip Companies, High-net-worth individuals and small to international size Architectural Practices.

From inception, we have built up a solid portfolio of impressive projects and continue to evolve as a modern thinking practice, improving on the old and adopting tried and tested new technologies to bring comfort, safety and energy efficiency to the building projects that employ our services.

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Director - Leon Gadsdon BEng(Hons) CEng MCIBSE

My decision to launch En Masse Design in 2001 was founded on and supported by a wealth of knowledge and experience as a building services engineer working on major developments in the UK and overseas.  I started my career as a trainee plumbing apprentice and completed my training with an honours degree in building services and environmental engineering.  During employment I have worked for some of the most highly regarded consultancy practices in the UK and gained invaluable knowledge.  Running my business has presented many challenges and a fuller understanding of the changes and needs of the construction industry.  Although I maintain and develop the company's core specialisms,  I am also able to offer my experience as an accredited expert witness to assist in civil disputes.
Aside from work I enjoy military fitness classes, I'm a member of Toastmasters International and play drums in a prog rock band.

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Mechanical Electrical & Public Health Consultancy Services

We design and specify the MEP services from commencement of a project to completion. Our expertise includes but is not limited to:

  • Statutory utilities applications and negotiations 

  • Air conditioning and comfort cooling systems

  • Heating plant, radiators, underfloor heating

  • Mechanical  ventilation systems

  • Natural ventilation and passive design 

  • Building automation, BEMS control systems

  • Renewable energy technologies, solar, wind, ground source and air source heat pumps

  • Public health hot and cold water, above and below ground drainage, rainwater collection and recycling systems

  • Electrical services power, standby generation, UPS and Transformers

  • Internal and external lighting and controls, emergency lighting

  • Fire systems incl. fire alarms, sprinklers, misting systems.

  • Security, access control, CCTV

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Technical Services Reporting & Surveying

We routinely carry out MEP surveying and reporting duties for clients on their existing services comprising: 

  • Asset condition and pre-acquisition reports

  • MEP dilapidation claims

  • Technical feasibility studies

  • MEP commissioning and validation reports.

  • MEP budget cost advice

We ensure our reports are concise, results focused and written in terms that are easily understood.

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Civil Expert Witness Services

As principal of En Masse Design, I have expert witness accreditation from Cardiff University Law School. 

I produce comprehensive advisory and court compliant expert witness reports.  I can act as party expert or single joint expert. 

As a Chartered Mechanical Engineer I possess extensive practical and academic knowledge obtained over a long established career.  I'm able to use these skills analytically to determine root cause and find workable solutions to technical problems.  I am able to interpret and present facts in a concise way.

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Dorset Works, London SW8

Dorset Works is an impressive commercial new build providing 700m.sq of open plan modern office space designed to British Council for Offices standards.  It is built on an extremely tight site previously an old Victorian warehouse.  
En Masse Design provided 2D and 3D MEP services design coordination for comfort cooling, heat recovery ventilation, HVAC controls, plumbing, power and detection services.

•    Client:     Private
•    Architects:     Carmody Groarke Ltd
•    MEP Consultants:     En Masse Design Ltd
•    Mechanical Contractor:     Tollhurst Ltd
•    Status:     Completed
•    Photographic image by:     En Masse Design


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Thorncroft Manor
Thorncroft Drive
KT22 8JB

Reception: 01372 224 745 Mobile: 07766 078 318

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