Loft Conversion
Structural Calculations & Drawings
Building Control-ready structural calculations and drawings for loft conversion companies across London and the UK. Fixed fee. Fast turnaround. Done properly.
Practical structural plans and calculations designed to make the construction details clear for builders, loft conversion companies and Building Control.
Long turnarounds from busy general engineers disrupt your programme and delay Building Control submissions.
Incomplete or generic structural calculations attract queries — and the delays that follow stall the whole job.
Vague layouts that miss beam positions, padstone sizes and joist centres make life harder for everyone on site.
The engineer behind
every package
I'm Tristan Wilkinson — Director of Design Axis with over 25 years of structural and architectural design experience. Every package that leaves Design Axis is personally signed off by me.
I've delivered over 700 domestic and commercial schemes — including over 250 structural calculation packages for loft conversions. I know exactly what Building Control needs to see, and every package is built around it.
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.
Simple to Instruct
Fast to Receive
We work from your architect's drawings. No site visit required.
Send Your Drawings
Email floor plans, roof plans and elevations as PDF or DWG. Include any existing structural information you have.
We Confirm the Fee
We review the scope and confirm a fixed fee in writing, usually within 24 hours. No obligation to proceed.
We Produce the Package
Load path assessment, member sizing and a complete Tekla Tedds calculation and structural drawing package.
Submit to Building Control
You receive the complete PDF pack by email. We respond to any Building Control queries on our package directly.
Fixed fee. Confirmed before we start
No hourly rates. No additions once the scope is agreed. Fee confirmed after drawing review — typically within 24 hours.
Send your architect's drawings and we'll confirm a fixed fee and scope. No commitment required.
Request a Fixed Fee QuoteReady to get started?
Email your architect's drawings — we'll confirm a fixed fee and scope within 24 hours. No commitment required.
info@designaxis.uk