6-Gate Design Process — Overview
The 6-Gate Design Process is Purple8's AI orchestration engine for generating complete architectural concepts from a brief. When you ask ArchitectPurple to design something, it runs automatically — taking your input through six structured gates, each with a human-in-the-loop checkpoint.
Triggering the process
The design process starts automatically when your prompt contains design intent:
Design a residential apartment development for a 0.4ha brownfield
site in Bristol. 60 units, mixed tenure, BREEAM Excellent.Generate a concept for a 3,000m² primary school in Manchester.Create a layout for a mixed-use scheme with 40 apartments above
1,200m² of retail on a corner plot.You can also trigger it explicitly:
Start a new design process for the Riverside Apartments project.The Six Gates
Brief → Site → Programme → Options → QCRT → Coherence
0 1 2 3 4 5| Gate | Name | What happens | Your action |
|---|---|---|---|
| 0 | Brief Interrogation | AI analyses the brief, fills gaps, flags ambiguities | Review + confirm |
| 1 | Site Grounding | Site and GIS data fetched and analysed | Review context card |
| 2 | Programme Synthesis | Room schedule generated from brief + site | Approve or edit |
| 3 | Design Options | 3 concept options generated with rationale | Select preferred |
| 4 | QCRT Optimisation | Quality, Cost, Regulatory, Technical checks | Review red flags |
| 5 | Coherence & Commit | Final synthesis, graph commit | Confirm to save |
Human-in-the-loop
Every gate ends with a checkpoint — the process pauses and waits for your input before proceeding. You can:
- Approve — accept the gate output and move to the next gate
- Edit — modify specific values (e.g. adjust room areas, change an option preference)
- Provide feedback — type a correction in natural language and the gate re-runs
- Restart the gate — discard the output and re-run from scratch
The process never proceeds autonomously past a checkpoint. You are always in control.
Viewing gate status
While the process is running:
- The AI Chat panel shows a progress indicator with the current gate highlighted
- Each completed gate shows a summary card with its key outputs
- A timeline strip at the top of the chat shows all six gates — click any completed gate to re-read its output
Resuming an interrupted process
If you close the browser or switch projects mid-process, the design process is saved. Return to the project and open AI Chat — you will see a Resume Design Process banner at the top.
After Gate 5 — continuing the design
Once the process completes and the design is committed to the graph, you can:
- Refine the layout in the LAD Engine
- Run Phase 8 Algorithms on the committed design
- Advance to the next RIBA stage in Journey
- Upload the IFC output to DocIntel for further processing
- Start a new design process for a specific part of the scheme (e.g. "design the ground floor retail in more detail")