Structural Design Services in London

Structural design is the engineering process of planning, analysing and detailing the parts of a building that carry load, so it is safe, stable and compliant with the Building Regulations (Part A). Lenio Consultants provides complete structural design and calculations for homes and commercial projects across Croydon, Sutton, London and the wider UK, from first concept to build-ready drawings.

Overview

What Is Structural Design?

Structural design ensures the elements that hold a building up, its foundations, beams, columns, slabs and connections, can safely carry every load placed on them and stay stable for the life of the building. It is what turns an architect’s vision into something that can actually be built and approved by building control.

At Lenio Consultants, we do far more than produce calculations. Our structural engineers in Croydon and Sutton analyse the loads, materials and site conditions of your project to create efficient, practical, buildable designs, developed to the UK Building Regulations, British Standards (BS EN) and Eurocodes. That reduces the risk of on-site problems, delays and extra cost, and keeps your project moving from design to construction.

We design directly from your architect’s drawings and project information, keeping the process efficient, convenient and cost-effective, wherever you are in Croydon, Sutton or the wider capital.

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Structural engineer preparing structural design calculations and drawings in Croydon

What We Offer

Our Structural Design Services in Croydon, Sutton & London

A complete structural design package covering every stage and material, for homeowners, architects, contractors and developers across Croydon, Sutton and London.

Residential Structural Design

Design and calculations for extensions, loft conversions, internal wall removals, basements and new homes, so your project is safe and passes building control.

Commercial Structural Design

Efficient structural systems for offices, retail, warehouses and mixed-use developments, balancing safety, durability and cost-effective construction.

Steel Structure Design

Steel beams (RSJs), columns, frames and connection details designed for strength and stability, and for straightforward fabrication and installation on site.

Reinforced Concrete Design

Foundations, slabs, retaining walls and concrete frames engineered for all relevant load conditions and long-term durability.

Timber & Masonry Design

Traditional and engineered timber and load-bearing masonry design for extensions, conversions and period-property alterations across Croydon, Sutton and London.

Structural Calculations

Clear, building-control-ready calculations that demonstrate every element meets UK safety standards and performs under the loads it carries.

Feasibility & Value Engineering

Early-stage advice on what is buildable, plus value engineering to reduce material use, simplify construction and control cost, without compromising safety.

Temporary Works & Retrofit

Needling, propping and shoring design, underpinning, and retrospective (as-built) calculations to verify and strengthen existing structures.

CAD & BIM Drawings

Coordinated structural drawings and 3D models, aligned with the architectural plans, for accurate construction and fewer surprises on site.

Do You Need It?

When You Need
Structural Design

You need structural design whenever you change how a building carries load. Planning permission controls what a building looks like; it does not confirm the structure is safe. That is a separate requirement, and it is where structural calculations come in.

Engaging a structural engineer early avoids redesigns, delays and building-control problems later.

Typical projects that need structural design:

Rear, side-return or wrap-around extensions
Loft conversions with steel (RSJ) beams
Removing a load-bearing wall or chimney breast
Forming large openings or knocking through
Basements, underpinning and new foundations
New builds, garden rooms and outbuildings
Strengthening or repairing an existing structure

See If Your Project Needs Calculations

Compliance Built In

The Standards We Design To

Every Lenio structural design is prepared to current UK codes, so it is safe, compliant and ready for building control.

Building Regulations Part A

Structure. The core UK requirement that a building must safely carry and transmit its loads to the ground.

Eurocodes & BS EN

The British and European structural design standards governing steel, concrete, timber, masonry and loading.

CDM 2015

Construction (Design and Management) Regulations, embedding health, safety and buildability into the design.

Terraced houses in Croydon and Sutton requiring careful structural design

Local Context

Structural Design for Properties in Croydon, Sutton & London

London’s buildings make structural design uniquely demanding. Victorian and Edwardian terraces, converted flats and constrained urban sites all behave differently when you extend, convert or excavate, and neighbouring buildings are rarely far away.

In Croydon and Sutton, many properties sit on London clay, making foundation design and subsidence assessment particularly important. The mix of period homes, post-war estates and newer developments across these boroughs means a local structural engineer who understands the ground conditions and building types can deliver more practical, buildable solutions.

A loft conversion usually means threading steel beams into existing walls; a rear or side-return extension needs new foundations and large openings; and basements involve underpinning and careful control of loads on adjoining structures. Listed buildings and conservation areas add further constraints that a good engineer designs around.

Where a project affects a shared wall or boundary, structural design and the Party Wall process often run together. Our sister practice, Lenio Party Wall Surveyors, can handle that side, so everything is coordinated.

Talk to a Structural Engineer in Croydon

From a Victorian terrace in Croydon to a semi in Sutton or a new build elsewhere in London, safe, efficient structural design is what keeps your project on track.

How It Works

Our Structural Design Process

A clear, staged process aligned with the RIBA Plan of Work, so you always know where your project stands.

Structural design drawings being prepared for a project in Croydon

Enquiry & consultation

We review your requirements and drawings, gather site information and confirm feasibility, then give you a fixed, no-obligation quote.

We work from your drawings

We design from your architect’s drawings or measurements and confirm the load-bearing elements and design criteria for the project.

Analysis & calculations

We complete the structural analysis and calculations to Eurocodes and UK standards, using industry-standard engineering software.

Structural drawings

We produce clear layout, steel, concrete and connection details, coordinated with the architectural plans for accurate construction.

Building control support

Every design complies with current Building Regulations and Eurocodes.

Your Deliverables

What You Receive

Everything your builder and building control need, in one clear, coordinated package.

Structural Calculations Pack

A full set of calculations demonstrating compliance, ready for building-control submission.

Structural Drawings

General arrangement, beam and foundation layouts, and connection details coordinated with your architect’s plans.

Engineer Support

Clear specifications, plus ongoing answers to builder and building-control queries throughout the build.

Accuracy You Can Trust

Quality Assurance Built In

Every drawing passes through a structured quality-assurance process before it reaches your site.

Our designs progress through preliminary and detailed stages before being issued as Good for Construction. Each is prepared, checked, independently reviewed and approved by a dedicated project team, which means high accuracy, full compliance with UK standards, and clear accountability at every stage.

Prepared

A technician and engineer produce the calculations and drawings.

Checked

A second engineer independently checks the design for accuracy.

Reviewed & approved

An independent reviewer and approver sign the design off before issue.

Good for Construction

The approved package is issued for building control and site.

Who We Help

Sectors We Work In

We provide structural design for homeowners, architects, contractors, developers, commercial businesses and builders across Croydon, Sutton, London and the South East.

Residential

Extensions, loft conversions, wall removals, basements, refurbishments and new homes.

Commercial & Mixed-Use

Offices, retail, hospitality and mixed-use schemes designed for flexibility and value.

Refurbishment & Heritage

Sensitive structural solutions for period, listed and conservation-area properties.

Explore our structural survey services, view our recent projects, or learn more about Lenio Consultants.

Accreditation

Chartered, ICE & CABE Members

The Institution of Civil Engineers (ICE)

The Chartered Association of Building Engineers (CABE)

Client Reviews

What Our Clients Say

Trusted by homeowners, architects and developers across Croydon, Sutton and London.

    
 
 
       Posted on Google  
   
   Sivasubramaniam Jeyaganesh 
 
 
 
 Trustindex verifies that the original source of the review is Google. I highly recommend Lenio Consultants Ltd! I recently worked with them on a structural drawing project and received a flawless Structural Design Calculation Report & Drawings.

A special thanks to Easan, Sarini and Malsha for their exceptional communication—they were incredibly supportive, responsive, and a true pleasure to work with throughout the process. The professionalism of the entire team is top-tier.

I will definitely be recommending them to my network and absolutely plan on using them again for our upcoming second side extension work. Thank you for the fantastic service!
  
 
      Posted on Google  
   
   Kannan Sri 
 
 
 
 Trustindex verifies that the original source of the review is Google. I am extremely satisfied with the structural engineer’s report. It was highly professional, clear, and a true reflection of the property’s condition. The inspection was carried out promptly, and the report was delivered as a matter of urgency without compromising on quality or detail. I would highly recommend their services to anyone needing a reliable and efficient structural assessment.
  
 
      Posted on Google  
   
   Ari Jatheeswaran 
 
 
 
 Trustindex verifies that the original source of the review is Google. Excellent structural design company with a very professional team. A special mention to Easan, who is truly a master of structures. His technical knowledge, clear communication, and attention to detail are outstanding. The work was delivered on time, and he was extremely flexible and supportive with all types of contractors. Highly recommended for quality, reliability, and professionalism.
  
 
      Posted on Google  
   
   Gerry Diver 
 
 
 
 Trustindex verifies that the original source of the review is Google. Eason carried out some structural surveying work for us and I honestly couldn’t recommend him more highly. He was punctual, courteous and extremely professional throughout. He spent real time on the job... was very thorough  and clearly takes pride in doing things properly rather than rushing.

He explained structural issues clearly and pragmatically, and inspired a lot of confidence in his judgement. Communication was excellent from start to finish and he was a pleasure to deal with

If you’re looking for someone reliable, highly skilled and genuinely diligent Eason is absolutely the person to call
  
 
      Posted on Google  
   
   Mary Sepamalai 
 
 
 
 Trustindex verifies that the original source of the review is Google. LENIO Consultants Ltd have been incredibly helpful. I loved how they provided expert suggestions while always respecting our own wishes—they never overlooked what we actually wanted. Their communication was swift, and I never had to chase them for drawings or submissions. I’d highly recommend them to friends and family!
  
 
      Posted on Google  
   
   sash siva 
 
 
 
 Trustindex verifies that the original source of the review is Google. I am extremely grateful to LENIO Consultants Ltd for their professionalism and outstanding support throughout my party wall matter. The adjoining owner was exceptionally difficult, which made the process both stressful and prolonged, However, the surveyor handled the situation with remarkable patience, calmness, and expertise.

He was clear, fair, and reassuring at every stage, and his in depth knowledge of the Party Wall Act was evident throughout. Thanks to his persistence and professional approach, the Party Wall Award was successfully completed.

I would highly recommend LENIO Consultants Ltd to anyone, particularly those facing a challenging neighbour situation.
  
 
      Posted on Google  
   
   Abbas Mohammed 
 
 
 
 Trustindex verifies that the original source of the review is Google. Ethan and his team were superb! They delivered the drawings within the very tight deadline (and did so quickly). The entire process, from start to finish, was well-communicated, robust, smooth, and affordable. I would definitely recommend anyone looking for planning drawings, structural-design advice, and more.

I'll certainly be recommending them to family and friends and will return for any future major projects.
  
 
      Posted on Google  
   
   Sam Suri 
 
 
 
 Trustindex verifies that the original source of the review is Google. Fantastic company to work alongside - they have gone over and beyond to help us complete a new project and are still there to support us with anything we need. Would highly recommend to anyone - trustworthy, polite, prompt and professional.
  
 
      Posted on Google  
   
   Kathiramu Arumukasamy 
 
 
 
 Trustindex verifies that the original source of the review is Google. Lenio consultants from start to finish had amazing service. They were able to get permission from Hillingdon council to extend our property 6m which is usually difficult to get. Great and professional service

Good to Know

Structural Design FAQs

What is structural design?

Structural design is the engineering process of planning and designing the framework that keeps a building safe and stable, its beams, columns, walls and foundations, so they carry the loads placed on them without failing. It also demonstrates compliance with the UK Building Regulations (Part A) and Eurocodes. At Lenio, we translate that analysis into clear calculations and drawings your builder can construct with confidence.

When do I need structural design services in Croydon, Sutton or London?

Whenever you make a structural change to a building: removing a load-bearing wall, building an extension, converting a loft, forming a large opening, digging a basement, or constructing something new. In each case a structural engineer confirms the new arrangement can safely support the loads. Engaging one early avoids redesigns, delays and building-control problems.

How much does structural design cost in Croydon and Sutton?

It depends on the scope. A single element, such as a beam calculation for a wall removal, sits at the lower end, while a full extension, basement or new build costs more. We provide a fixed, transparent quote before any work begins, so there are no surprises. Send us your drawings or a short description and we will quote quickly, with no obligation.

Are structural calculations required for building control approval?

In most cases, yes. Building control (your local authority or an approved inspector) usually requires structural calculations to confirm the project meets UK safety and construction standards. We prepare clear, submission-ready calculations and drawings to support your application, and answer any queries that come back.

Can I remove a load-bearing wall?

Yes, but only with a proper structural design by a qualified structural engineer. Removing a load-bearing wall needs a suitable support, usually a steel beam, to safely transfer the load the wall was carrying. Building control approval is normally required before work starts. We assess the wall, design the support and provide the calculations you need.

What standards do you design to?

All our designs are prepared to the UK Building Regulations (Part A, Structure), the Eurocodes and relevant British Standards (BS EN), with health, safety and buildability addressed under CDM 2015. This ensures your structure is safe, compliant and ready for building-control sign-off.

What do you need from me to provide a quote?

Ideally your architect’s drawings (existing and proposed) or a clear description and photos of the works, plus the property address. Even at an early stage we can advise on what is required and give you a fixed quote. If drawings are not ready yet, we can still point you in the right direction.

How long does a structural design project take?

Most residential structural designs are completed within a few working days to two weeks, depending on scope and complexity. Larger or more complex projects need longer for analysis and coordination. If you have a deadline, tell us and we will advise on timescales and work to meet it wherever possible.

Which areas do you cover from Croydon?

Lenio Consultants is based in Croydon and provides structural design across Croydon, Sutton, the whole of London including North, South, East, West and Central London and every borough, as well as the wider South East and UK. Wherever your project is, you receive the same chartered-standard engineering and clear communication.

Start Your Structural Design Project

Send us your project details and our chartered structural engineers in Croydon and Sutton will prepare a fixed, no-obligation quote and take you from concept to build-ready drawings.

Call +44 20 4558 8272 Get a Free Quote