Recognising an arbitrary composition
In our editorial composition assessment, an arbitrary scheme can look like this: three or four cladding types in roughly similar quantities, each stopping wherever the elevation drawing happened to divide. Nothing is dominant, nothing is subordinate, and no material change corresponds to anything about the building.
It looks arbitrary because it is arbitrary. The materials were chosen to add interest to a flat elevation rather than to express something already there.
Rule 1: one dominant, one subordinate
As an editorial composition starting point, try one material over roughly 70–80% of the visible elevation, with a second marking an entrance or volume. This is a sketching suggestion, not an industry rule or performance threshold.
Takeaway: Label the dominant field and the purpose of each accent on the elevation.
Rule 2: change where the building changes
A material change reads as deliberate when it coincides with something real:
- A change of form — where a volume steps back, projects, or changes height
- A change of function — a plinth at ground level, a service zone, a garage
- A clear horizontal datum — a floor line, a window head line, a level change
- A change of exposure — a sheltered elevation treated differently from an exposed one
It reads as arbitrary when it stops mid-surface with nothing to justify the position.
Takeaway: Trace each material boundary to a labelled volume edge, function, datum or exposure change.
Rule 3: fewer transitions
This is a performance rule as much as an aesthetic one.
At every junction between two cladding systems, check:
- Movement allowance for the actual materials and their supports
- A fixing problem, because they are usually carried on different systems at different depths
- A water path, because a change of plane and material is where water finds its way in
- A buildability problem, because two trades meet there and the sequencing matters
Each of those has a solution, and each solution costs money and can be got wrong. Under otherwise equal conditions, two transitions leave fewer nodes to resolve than six; that does not establish a reliability ranking.
Takeaway: Give every transition a detail reference and a named coordinator.
The conventional arrangements that work
Heavy below, light above. Masonry plinth, lighter cladding above. Matches how loads and splashing work, and puts the impact-resistant material where impact happens.
Frame and infill. One material forms a continuous frame or surround; the second fills the panels within it.
Volume by volume. In a building of distinct volumes, one material per volume, changing at the junction between them.
Elevation by elevation. A different treatment on the street face and the garden face, changing at the corner. Works because the corner is a real edge.
What changes over ten years
Materials weather at different rates and in different directions. Timber greys, some renders chalk, metals dull, masonry darkens and streaks below sills and copings.
A combination chosen for how it looks new can diverge substantially. Two things help:
- Check how each material weathers in your climate, not in a brochure photograph.
- Design the water run-off. Run-off can carry dirt from one surface onto another. Check the drainage detail rather than relying on a material boundary alone.
Takeaway: Review both future appearance and run-off before fixing the palette.
Before committing
Use this transition record after confirming fire requirements and the cladding system.
| Node check | Record before approval |
|---|---|
| Location and purpose | Elevation / boundary: ___ |
| Drawing reference | Detail number / revision: ___ |
| Trade responsibility | Upper cladding / lower cladding / flashing installer / coordinator: ___ |
| Water and movement | Drainage outlet / movement allowance / evidence: ___ |
| Maintenance access | Reach route / removable parts / responsible person: ___ |
Takeaway: Resolve the handover between trades before approving the material boundary. Compare maintenance demands, exterior cladding options and the facade guide.
Frequently asked questions
How many materials is too many?
Our editorial composition advice is to start with a dominant material and a limited accent. Four materials are not inherently unworkable; check whether each change has a clear purpose and boundary.
Should the change be horizontal or vertical?
Horizontal changes at a datum — a floor line, a window head, a level change — read as calm and relate to how the building is built. Vertical changes work when they follow a change in plan or form. Diagonal or arbitrary changes rarely work.
Can I mix a heavy and a light material?
Yes, and the conventional arrangement is the heavier material below and lighter above, because it matches how loads and weathering work. Reversing it can be done deliberately but reads as a statement rather than a default.
What happens at the junction between two claddings?
Differential movement, different fixing depths and a potential water path, all in the same place. The junction needs a flashing or a designed reveal, and it needs to be drawn as a detail rather than assumed.
Sources
- Building Envelope Design Guide — Whole Building Design Guide, National Institute of Building Sciences Accessed August 27, 2026.