The Complete Process: From Planning Permission to Building Regulations to Construction (2025 UK Guide)
By Kieran Atherton — Architectural Designer & Director of Melrose Designs
planning permission to building regulations process
Why This Guide Matters
Most homeowners (and many designers) underestimate how long and detailed the journey is from a first idea to a finished extension. They often ask:
- “Do I need planning permission, or can I skip straight to drawings?”
- “When do I need structural calculations?”
- “What happens after Building Regulations approval?”
- “Who informs Building Control and the builder?”
As someone who submits hundreds of planning and Building Regulations drawings every year across Wigan, St Helens & Greater Manchester, I built this guide to simplify the entire process.
Sub-Topic Pages:
“The Melrose Method™ – A Clear Path from Planning to Construction”
planning permission to building regulations process
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Overview of the Full Journey: Planning → Building Regs → Construction
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Here is the full process in a simple flow:
- Concept Design & Feasibility
- Planning Permission (if required)
- Technical Drawings for Building Regulations
- Structural Calculations
- Builder Pricing & Tendering
- Building Control Approval
- Construction Phase
- Sign-Off & Completion Certificate
Many clients don’t realise these are distinct stages, each requiring different types of drawings and paperwork.
The Melrose Method™ makes the journey predictable by breaking each stage into clear milestones.
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Planning Permission Stage (Optional, but often required)
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When Planning Permission IS required
- Side extensions creating wrap-arounds
- Extensions near highways
- Flats & HMOs
- Major alterations to roof shape (in restricted areas)
- New dwellings or conversions
Typical Planning Timeline
Stage Duration
Initial drawings 1–2 weeks
Submission Same day
Validation 1 week
Consultation period 21 days
Decision 8 weeks
What Melrose Designs supplies at this stage
- Existing + proposed plans
- Elevations + roof plans
- Site plan with red/blue line boundary
- Planning statements (when needed)
- Location plans
- Neighbour consultation advice
Designer Tips for Faster Approvals
- Keep rooflines simple
- Pre-check neighbour windows (avoid overshadowing issues)
- Speak to neighbours before submission
- Provide a clear design and access statement
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Building Regulations Stage (Always Required)
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Planning permission only gives you permission to build, not approval how to build.
Building Regulations drawings contain:
- Insulation specifications
- Fire safety details
- Structure and foundations
- Drainage layout
- Roof build-ups
- Steel beams, joists & connection details
- Ventilation strategy
- Thermal calculations (SAP, U-values)
What Melrose Designs Provides
- Full Building Control drawing pack
- Structural calculations (working with engineers when required)
- Detailed construction notes
- Specifications for materials
Common Mistakes Homeowners Make
- Thinking planning drawings = building regs drawings (they don’t)
- Choosing a builder before getting regulated drawings
- Starting work before Building Control approval
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Structural Calculations & Engineering
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Once the architectural drawings are ready, a structural engineer calculates:
- Steel beams (RSJs)
- Padstones
- Roof loads
- Floor strengthening
- Removal of internal walls
- Foundations and ground-bearing checks
Designer Tip:
Always design the steel layout early.
A redesign at construction stage is expensive and delays the build.
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Builder Pricing, Tendering & Contracts
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Once Building Regulations drawings + structural calculations are complete:
You can now:
- Get quotes from multiple builders
- Compare prices based on the same information
- Avoid “guess quotes” that lead to variations later
Tip for Homeowners
- Ask for a fixed-price schedule with:
- Start and finish date
- Payment stages
- List of included & excluded items
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Building Control Approval
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Two options:
- Private inspector (Approved Inspector)
- Local authority Building Control
Both will:
- Check the drawings
- Inspect key stages of the build
- Issue a Completion Certificate
Stages Building Control Usually Inspects
- Foundations
- DPM / concrete pour
- Structural steel installation
- Insulation before plasterboard
- Final completion
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Construction Phase Timeline
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Every build differs, but here is a typical extension timeline:
Stage Duration (Approx.)
Groundworks & foundations 1–3 weeks
Drainage 1 week
Block/brick walls 2–4 weeks
Roofing 1–2 weeks
Windows & doors 1 week
First fix (electrics/plumbing) 1–2 weeks
Insulation & plasterboard 1–2 weeks
Plastering 1 week
Second fix 1–2 weeks
Snags & completion 1 week
Total typical duration: 8–16 weeks depending on size.
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The Melrose Designs Difference (E-E-A-T)
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Why homeowners choose Melrose Designs
- 10+ years specialising in home extensions
- 1,000+ successful planning & Building Regs submissions
- Background in structural & BIM coordination
- Fast lead times (planning drawings in 7–14 days)
- Clear communication with councils, engineers & builders
A refined process known as:
“The Melrose Method™ – A Clear Path from Planning to Construction”
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FAQs
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How long does planning permission take in the UK?
Typically 8 weeks after validation.
Do I need Building Regulations approval?
Yes — almost every extension requires Building Regulations even if planning isn’t needed.
When do I need structural calculations?
Anytime a beam, opening, or load-bearing wall is involved.
Can builders start work without Building Control approval?
No — this risks enforcement action and invalidates certification when selling the property.
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Quick-reference Table
Understanding the Planning Permission to Building Regulations Process
Stage | Purpose | Required? | Who Does it? |
|---|---|---|---|
Planning Permission | Permission to build | Sometimes | Melrose Designs |
Building Regulations | Ensures safe construction | Always | Melrose Designs |
Structural Engineering | Beam & load design | Usually | Engineer |
Builder Tendering | Accurate pricing | Always | Homeowner |