Structural Calculations,
Surveys & Reports
Building Control-ready structural calculations and drawings, together with structural surveys and reports for homeowners, surveyors, architects and property professionals.
From loft conversions and wall removals to cracking, movement and defects identified during property surveys — clear structural engineering advice, practical recommendations and fixed fees.
Structural Calculations & Drawings
Building Control-ready structural design for residential alterations, extensions and loft conversions. Clear calculations and practical drawings prepared using Tekla Tedds.
- Loft conversions
- Extensions
- Steel beam calculations
- Load-bearing wall removals
- Columns and goalpost frames
- Foundations and padstones
- Roof alterations
- Chimney breast removals
Structural Surveys & Reports
Independent structural assessments for defects, movement and concerns identified during property surveys or home purchases. Desktop reviews and site inspections as required.
- Cracking and movement
- Suspected subsidence
- Settlement and differential movement
- Bulging or leaning walls
- Roof spread and defects
- Previous structural alterations
- Defective lintels
- Foundation concerns
We work across two main service areas
We can review the survey findings, advise on the appropriate level of investigation and provide a fixed fee for a structural report.
We investigate the likely cause and advise whether repair, monitoring or further investigation is appropriate — after site inspection if required.
We prepare clear calculations and drawings for domestic structural alterations — loft conversions, extensions, wall removals, steel beams and more.
Our reports explain the structural issue, its significance and the recommended next steps — without unnecessary complication or engineering jargon.
Building Control-ready structural design for residential alterations
From a straightforward steel beam to a full loft conversion structural package — calculations prepared using Tekla Tedds and drawings produced to Building Control standard.
Loft Conversions
Full structural packages for Velux, rear dormer, hip-to-gable, mansard and L-shaped conversions. Steel beams, floor joists, rafters, padstones, stair trimming and all member schedules.
Extensions
Structural design for single and double-storey extensions, including foundations, ground beams, padstones, structural lintels and roof steelwork.
Load-Bearing Wall Removals
Steel beam sizing, padstone design, temporary propping sequences and all supporting calculations required for Building Control approval of internal wall removals.
Steel Beam Calculations
EC3 bending, shear, deflection and web bearing checks for UB, UC and RSJ sections. Connection design, splice plates and bearing details where required.
Foundations & Padstones
Foundation design for extensions and alterations. Padstone sizing and bearing calculations for new steelwork, together with ground bearing capacity assessments.
Structural Alterations
Columns, goalpost frames, chimney breast removals, roof alterations and general domestic structural alterations — all prepared to Building Control standard.
A complete structural package for your loft conversion
Calculations, structural layout plans, section details and member schedules — so builders can price, Building Control can check, and the project can move forward.
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Structural Layout & Section Plan Dimensioned plans showing beam positions, joist layout, padstone locations, key section details and all structural member references.
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Structural Member Schedule Every steel and timber member listed with section size, grade, span and drawing reference — ready for the builder, estimator and Building Control.
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Beam Loading Summary A clear breakdown of the floor, roof, partition and dormer loads applied to each beam, with the final design loads set out so Building Control can check the calculation route easily.
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Steel Beam Calculations EC3 bending, shear, deflection and web bearing checks for every UB, UC and RSJ included in the package.
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Timber Flitch Beam Calculations Combined steel plate and timber flitch beam design where composite sections are used instead of solid steel.
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Floor Joist Calculations EC5 design for new loft floor joists at the specified centres, including bending, shear, deflection, trimming and support checks.
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Rafter Calculations EC5 rafter design for altered roof structures, including ridge beams, purlins, collar ties and new roof members where required.
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Stair Opening & Trimmer Calculations Trimmer joist and trimming joist checks around the stair opening, with hanger, bearing or steel support details as required.
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Steel Connections & Splices Fin plate, end plate, splice plate and beam-to-beam connection design where required, including practical installation notes.
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Padstone, Bearing & Restraint Details Padstone sizes, bearing requirements, restraint straps, hangers and key support notes clearly specified so the steelwork and joists can be installed correctly on site.
Every standard loft conversion type. Covered
The structural scope varies by conversion type — we confirm exactly what's required as part of your fixed fee quote.
Velux / Rooflight
Trimmer joists, rafter checks, stair opening.
Rear Dormer
Steel beam, flat roof framing, floor joists, bearing checks.
Hip-to-Gable
Hip removal, new gable framing, ridge extension.
Mansard
Steelwork, mansard wall structure, full load redistribution.
L-Shaped Dormer
Valley beam, compound joists, dual dormer framing.
Front Dormer
Steel beam, front elevation framing, bearing checks.
Side Dormer
Flank wall steelwork, side framing, floor joists.
Bungalow
Full load path redesign, new floor structure, steelwork.
Has a surveyor identified a structural concern?
We provide structural assessments for homeowners, surveyors and property professionals where cracking, movement or another structural concern has been identified — whether during a Home Survey, a property purchase or an existing owner's concern.
Specific Structural Defect Report
For a clearly defined concern — cracking, movement, roof spread, a removed wall, localised settlement or another structural defect identified during a property survey or inspection.
Structural Inspection Report
Following a site visit to the property. We inspect the relevant areas, assess the structural concern and prepare a clear written report setting out our findings and recommendations.
Structural Condition Assessment
For more complex properties or where several structural concerns require assessment. Suitable where a surveyor has identified multiple issues requiring specialist structural input.
Desktop Structural Review
Where adequate photographs, drawings and survey information are available, a preliminary structural review can be carried out without an initial site inspection. We advise whether this is appropriate for your situation.
Structural engineer support for building surveyors
When a Level 2 or Level 3 Home Survey identifies cracking, movement or a potential structural defect, Design Axis can provide the specialist structural assessment required to take the matter further.
We work with surveyors, purchasers and property professionals to investigate specific structural concerns and provide clear written advice on the likely cause, significance and recommended next steps — whether that requires a desktop review or a site inspection.
Cracking & Movement
Assessment of cracking patterns, distortion and evidence of historic or ongoing structural movement. We advise on likely cause, significance and whether further investigation or monitoring is required.
Subsidence & Settlement Concerns
Assessment of possible foundation movement, differential settlement and potentially drainage-related movement. We advise on the appropriate level of investigation.
Roof & Structural Timber Issues
Assessment of roof spread, altered roof structures, overloaded members, ridge and purlin defects, and other structural issues within the roof space.
Alterations & Removed Walls
Assessment of previous structural alterations, removed load-bearing walls, removed chimney breasts and questionable support arrangements requiring specialist structural review.
External Walls & Structures
Assessment of leaning or bulging walls, boundary walls, retaining walls, masonry defects and external structural concerns identified during the survey process.
Specific Defect Reports
Focused structural reports responding directly to an issue identified within a Home Survey. Suitable for forwarding to the purchaser, solicitor or other property professional involved in the transaction.
Buying a property with a structural concern?
If your surveyor has recommended further investigation by a structural engineer, we can assess the issue and provide clear advice before you proceed with the purchase.
Send the Survey
Send the relevant pages from your Level 2 or Level 3 Home Survey together with photographs and the property address. No need to send the whole report.
We Review the Concern
We review the information, advise whether a desktop assessment or site inspection is appropriate and confirm a fixed fee before any work proceeds.
Receive the Structural Report
You receive a clear structural assessment setting out the likely cause, significance, recommended action and whether any further investigation is required.
What clients say
I was recommended Tristan Wilkinson and Design Axis by Carpenter Surveyors to provide a structural survey on a property we are buying.
Tristan initially reviewed the survey from Carpenter and recommended a site visit. This was arranged quickly. His report was issued a few days after the site visit and was very thorough, and included some very helpful photographs of the concerns expressed in the original survey. His report was very clear and concise and advised on recommendations to be carried out to mitigate the issue identified. I was very pleased with the service from Tristan and Design Axis — they were very easy to deal with and spoke in terms that were easy to understand.
I would have no hesitation in recommending Tristan and Design Axis to anyone looking for a structural surveyor.
As a first time buyer the process of organising surveys was something completely new to me and quite overwhelming. From the beginning Tristan was extremely helpful. He explained everything so that I could understand, was supportive and informative and made the whole process extremely easy. He responded quickly to all communication and never made me feel like I was a bother! An absolute delight to deal with and I would highly recommend his services.
I would highly recommend Tristan Wilkinson for their excellent service and professionalism.
I needed foundation calculations for my building project at relatively short notice, and they were extremely helpful in accommodating my requirements. They provided the calculations promptly and professionally, giving me confidence that the foundation design had been properly considered and was suitable for the project.
Communication was clear throughout, and they were responsive, knowledgeable, and easy to deal with. I really appreciated their willingness to assist within a tight timeframe without compromising on the quality of their work.
I would have no hesitation in recommending Tristan Wilkinson to anyone looking for a reliable and professional structural engineering service.
We recently had the pleasure of working with Tristan as both our architect and structural engineer for our extension, and we honestly couldn't recommend him highly enough.
From our very first conversation, Tristan was friendly, approachable and really took the time to understand what we wanted to achieve. He didn't just look at the plans and get on with it — he listened to our ideas, talked everything through with us and gave us advice and suggestions where needed, which was really appreciated.
His attention to detail was excellent, and it was clear throughout the whole process that he has a huge amount of knowledge and experience. He was thorough with everything, explained things clearly and was always happy to answer any questions we had, no matter how small.
What really stood out to us was how easy Tristan was to deal with. He was professional but also very personable, and we always felt that he genuinely cared about getting the best possible result for us. He made what could have been quite a complicated process feel straightforward and manageable.
We are extremely happy with the work he carried out for us and the level of service we received. It's not often you come across someone who is so knowledgeable, reliable and easy to work with.
10/10 from us — brilliant service, excellent knowledge and a genuinely great person to deal with from start to finish.
We have hired Design Axis on 2 occasions and have found them to be extremely professional with very detailed reports.
On the first instruction, structural slab details were required by our client. We supplied slab core samples along with bore hole results to Design Axis, and they provided a fully detailed and comprehensive report — our client was very impressed.
On the second instruction, our client had an issue with a collapsing wall to a main line railway embankment. We employed Design Axis to make a site visit to investigate and provide a full report. Design Axis supplied an impressive multi-page report, and the client was so impressed they have asked for a programme to commence all works as itemised.
We have used different structural engineers over the past 40 years, but Design Axis are without doubt the best for us. We will certainly use them again.
The engineer behind
every package
I'm Tristan Wilkinson — Director of Design Axis, with over 25 years of structural and architectural design experience across residential and commercial construction.
I have worked on hundreds of residential projects ranging from loft conversions and extensions to structural defects, movement investigations and remedial works. Every structural calculation package and structural report issued by Design Axis is reviewed and signed off by me.
I know what Building Control needs to see in a structural calculation package, and I understand what surveyors, purchasers and property professionals need from a structural report — clear findings, a considered assessment and practical next steps.
Simple to Instruct
The process is the same whether you need structural calculations or a structural report.
Send the Information
For calculations: send architectural drawings, plans or sketches. For a report: send the survey extract, photographs, the property address and details of the structural concern.
We Review the Scope
We review the information and confirm whether any further details, investigation or site inspection are required before a fee can be confirmed.
Fixed Fee Confirmed
The scope, fee and expected turnaround are confirmed in writing before work starts. No commitment required to receive a quote.
Calculations or Report Issued
The completed structural calculation package, drawings or structural report is issued electronically. We respond to any follow-up queries on our work directly.
Fixed fee confirmed before we start
No hourly rates. No additions once the scope is agreed. The fee is confirmed after reviewing your information — typically within 24 hours for structural calculations.
Send your drawings or survey details and we'll confirm a fixed fee and scope. No commitment required.
Request a Fixed Fee QuoteReady to get started?
Send your drawings, survey extract or details of your structural concern. We'll confirm the scope and a fixed fee — no commitment required.
info@designaxis.uk