The short answer
RIBA Stage 3 and Stage 4 are the two middle stages of the RIBA Plan of Work that take an agreed concept and make it real. Stage 3 (Spatial Coordination), formerly called developed design, is where the concept is coordinated into a resolved scheme — layout, structure and services working together — and for most home projects this is where the planning application is prepared and submitted. Stage 4 (Technical Design) is where the design is detailed enough to build: construction build-ups, insulation, structure, drainage and specifications are produced, forming the building regulations package and the drawings the builder works from. In short, Stage 3 settles what the building is and gets it through planning; Stage 4 works out exactly how it is built. Both are essential — a Stage 3 set alone is not enough to construct from.
If your architect quotes "to Stage 3" or "Stages 3 and 4", it pays to know the difference — because where the fee stops decides whether you have enough information to build.
The two stages compared
- Stage 3 nameSpatial Coordination (developed design)
- Stage 3 outputCoordinated scheme + planning
- Stage 4 nameTechnical Design
- Stage 4 outputBuilding regs + construction set
- Build-ready?Only after Stage 4
RIBA Stage 3 — Spatial Coordination
Stage 3, renamed Spatial Coordination in the 2020 Plan of Work but still widely called developed design, takes the agreed concept and resolves it properly:
- Coordination: the layout, structure, services and circulation are worked through so they fit together and the scheme is genuinely workable, not just a nice-looking sketch.
- Resolved drawings: the existing and proposed plans, elevations and sections are firmed up to a consistent, coordinated standard.
- Planning application: for most home projects this is the stage at which the planning application is prepared and submitted to the local authority, because the design is now settled enough to seek approval for its form and appearance.
- Early consultant input: a structural engineer or other specialist may start contributing so the scheme is feasible before it is detailed.
By the end of Stage 3 you should have a design you are committed to and, typically, a planning application in. What you do not yet have is the detailed information needed to build it.
RIBA Stage 4 — Technical Design
Stage 4, Technical Design, is where the resolved scheme becomes genuinely buildable. This is the most detailed design work and produces the information that contractors and Building Control rely on:
- Construction build-ups: exactly how walls, floors and roofs are made up, including insulation and weatherproofing.
- Building regulations package: the annotated drawings and specifications that demonstrate compliance with the Building Regulations for structure, fire, insulation, ventilation, drainage and more.
- Coordinated consultant information: the structural engineer's calculations and drawings, and any other specialist input, are integrated.
- Specifications and details: the materials, products and junction details the builder needs to price accurately and construct correctly.
| Aspect | Stage 3 (Spatial Coordination) | Stage 4 (Technical Design) |
|---|---|---|
| Main purpose | Resolve + coordinate the scheme | Make it buildable |
| Key approval | Planning application | Building regulations |
| Drawing detail | Coordinated design level | Full construction detail |
| Who contributes | Architect (+ early consultants) | Architect + structural engineer etc. |
| Enough to build? | No | Yes |
Comparison based on the RIBA Plan of Work 2020. Source: RIBA.
Why the difference matters to you
The practical reason to understand these two stages is fees and information. Architects frequently quote in stages, and a very common arrangement is a fee up to Stage 3 (design and planning), with Stage 4 (technical design) quoted separately. If you stop at Stage 3, you have planning permission but not the drawings to build from — which means:
- Builders pricing from a Stage 3 set are estimating the construction, so quotes diverge and costs are uncertain.
- You cannot submit for building regulations approval without the technical information.
- The risk of expensive changes on site rises sharply because details were never resolved on paper.
This does not mean you must commission Stage 4 from the same architect — some homeowners take a planning approval and have the technical drawings prepared elsewhere, or by a contractor's designer. But you do need Stage 4 information from someone before a builder can price and build properly. When comparing fee proposals, always check which stages are included, and budget for technical design even if it is a separate step.
Frequently asked questions
Is planning submitted at Stage 3 or Stage 4?
Planning is usually submitted at Stage 3 (Spatial Coordination), once the concept is coordinated into a resolved scheme. Stage 4 (Technical Design) comes afterwards and produces the detailed building regulations and construction drawings.
Can I build from Stage 3 drawings?
No. Stage 3 drawings resolve the design and get it through planning, but they lack the construction detail, build-ups and specifications a builder needs. You need Stage 4 technical design information before you can price and build the project safely.
What was Stage 3 called before?
In the 2020 RIBA Plan of Work, the old developed design stage was renamed Spatial Coordination, which is now Stage 3. Many architects still use "developed design" informally, but the role — coordinating the scheme and submitting planning — is the same.
Sources & further reading
- RIBA — the RIBA Plan of Work 2020 stages
- GOV.UK — building regulations approval
- Planning Portal — planning permission and building regulations
Figures on this page are typical UK ranges drawn from published sources and depend on your specific project. They are guidance, not a quotation.