Scaffolding is at the core of safe construction, yet one of the most common questions contractors, developers, and site managers face is:
“Do I need a bespoke scaffold design, or will TG20:21 cover me?”
The answer depends on your project’s complexity, compliance requirements, and the risks involved. In this article, we’ll break down TG20:21, explore where it applies, and explain when a bespoke scaffold design is essential.
What is TG20:21?
TG20:21 is the National Access and Scaffolding Confederation (NASC) guidance that provides a framework for standard tube-and-fitting scaffolds. It simplifies compliance by setting out pre-calculated, commonly accepted designs that meet BS EN 12811-1 requirements.
TG20:21 offers:
Standard configurations (e.g. independent scaffolds, tied scaffolds, birdcages, loading bays).
Compliance sheets that demonstrate your scaffold meets legal requirements.
Guidance notes for contractors, scaffolders, and safety inspectors.
👉 For straightforward projects, TG20:21 often saves time and cost by avoiding the need for bespoke engineering calculations.
When is TG20:21 Enough?
TG20:21 is well-suited for:
Low-rise commercial scaffolds with standard tie patterns.
Simple residential builds such as extensions or roofline access.
Internal birdcage scaffolds that meet the height and bay limits.
Scaffolds with standard loading bays that do not exceed set capacities.
If your project falls neatly into TG20:21’s “standard” rules, you can often proceed without bespoke design work—though it’s still best practice to have an engineer confirm compliance.
When Do You Need a Bespoke Scaffold Design?
Many projects go beyond TG20:21’s standard range and require custom engineering drawings and calculations. These include:
1. Cantilever Scaffolds
Where ground conditions or site constraints prevent scaffolding from being supported directly, cantilevers are necessary. These cannot be covered by TG20:21.
2. Temporary Roofs
Protecting works from weather often requires temporary roof scaffold design, which demands bespoke analysis for wind loadings and bracing.
3. High Loads & Heavy Duty Platforms
If scaffolds must carry storage, materials, or machinery, TG20:21’s standard load classes may not be sufficient. Bespoke calculations ensure stability.
4. Complex Geometry & Heritage Structures
Unusual shapes (curved facades, towers) or listed buildings often require tailor-made scaffolds to avoid damaging the structure.
5. Infrastructure Projects
Large-scale works such as railways, highways, or utilities nearly always require custom scaffold drawings and CAT 2/3 checks for compliance.
👉 At Fox Scaffold Design, we specialise in 2D & 3D AutoCAD scaffold drawings and bespoke calculations to meet these challenges.
The Cost & Risk of Skipping Bespoke Scaffold Design
Choosing not to invest in bespoke scaffold design when required can result in:
Failed safety inspections → costly delays to your programme.
Non-compliance with BS EN 12811-1 / BS 5975 → risk of legal or regulatory action.
On-site accidents → liability for injuries or damage.
Rebuild costs → if scaffolds have to be dismantled and re-erected.
In contrast, a properly engineered scaffold drawing provides peace of mind, speeds up approvals, and saves money by avoiding rework.
At Fox Scaffold Design, we provide:
Scaffold Drawings → clear 2D/3D AutoCAD drawings with tie patterns, bracing, and loading notes.
Our Services → structural calculations, site surveys, CAT 3 checks, and temporary works.
Gallery → real-world examples of bespoke scaffold solutions.
Contact Us → discuss your project with our engineers today.
Unsure if TG20:21 is enough for your project?
Our engineers can review your scaffold requirements and advise whether a bespoke design is necessary.
👉 Request a Free Consultation today and ensure your project is safe, compliant, and efficient.
Frequently Asked Questions (FAQs)
1. What does TG20:21 cover?
TG20:21 covers many standard tube-and-fitting scaffolds such as tied independent scaffolds, birdcages, and loading bays—within specific height and load limits.
2. Do I always need bespoke scaffold design?
No. Bespoke design is only required where scaffolds fall outside TG20:21 limits (cantilevers, temporary roofs, high loads, unusual geometry).
3. Are TG20:21 compliance sheets enough for inspectors?
Often yes, but for complex sites or principal contractors, bespoke calculations and drawings are expected.
4. What standards must bespoke designs follow?
All bespoke scaffold designs must comply with BS EN 12811-1 and be managed under BS 5975 temporary works procedures.
5. How quickly can I get scaffold drawings?
At Fox Scaffold Design, we offer fast turnaround and 24/7 call-outs for urgent projects.
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