Richards Medical Research (1961)
Laboratory towers (served) framed by brick stair and exhaust towers (servant). The canonical built tartan — services given architectural form.
Architecture · wide + narrow bands · Kahn to Müller-Brockmann
Tartan grid — served and servant bands
The tartan grid is a structural grid with a conscience: instead of one repeating bay it alternates a wide band with a narrow one, so the things every plan struggles to place — columns, corridors, ducts, partitions — get a dedicated zone of their own. Borrowed from the Scottish sett and sharpened by Louis Kahn's distinction between served and servant spaces, it is equally at home in a laboratory plan and a magazine layout. Here is what it shows, where it comes from, and when the double rhythm earns its place.
- Pattern origin
- Scottish tartan sett
- Architectural use
- 1961 (Kahn, Richards)
- Origin culture
- Textile → design & architecture
- Difficulty
- Intermediate
- Structure
- Wide + narrow bands
- Also known as
- Plaid grid, double grid
See the tartan rhythm on five reference subjects
‹›
On an architectural elevation the wide bands fall on the glazed served bays and the narrow bands on the structural and service piers — the plaid you read in the facade is the tartan grid itself.
What the overlay shows
A tartan grid in architecture is a compound grid of alternating wide and narrow bands — not the fabric pattern, though it borrows the name. The overlay draws two interleaved rhythms in each direction: a wide band followed by a narrow band, repeating across and down. Where the bands cross, the field reads as a plaid — broad squares of "served" area framed by thin "servant" strips. The wide bands are where the content lives: rooms, galleries, text columns. The narrow bands are the dedicated home for everything that supports the content: structure, circulation, ducts, partitions, gutters, and margins.
In Grid Maker Pro the wide-to-narrow ratio and the spacing are both adjustable, so the same overlay produces a tight 6:1 laboratory plan or a loose 3:1 editorial layout. Drop it on a blank canvas to plan, or lay it over a photograph of a banded facade or a printed spread to read the rhythm already present.
The math, briefly
A tartan grid is the simplest compound grid: a single bay replaced by two interleaved modules that tile as a repeating unit.
repeat unit = W (served) + N (servant) · ratio W : N ≈ 3:1 to 6:1
Three things follow from that structure:
- The servant band is sized by its job, not by aesthetics. N has to be exactly wide enough for the corridor, the structural line, or the duct riser it carries — no more, because that area is stolen from the served space; no less, because the service has to fit.
- The rhythm can differ in the two directions. A plan can have a coarse served-servant rhythm across (rooms and corridors) and a different one down (floors and mechanical zones), which is exactly why Kahn's laboratory sections look different from his plans.
- It nests with a planning module. Both the wide and narrow bands are normally whole multiples of a base module so the tartan still coordinates with cladding panels and partitions — the same discipline as a single structural grid.
For overlay work the key is that two modules, not one, give you somewhere to put the supporting elements. Try it in the live tool and adjust the ratio until the servant band is exactly large enough.
History — what is real and what is myth
Verified history (with primary sources)
The Scottish sett. Tartan cloth is woven from a sett — a fixed sequence of coloured bands of differing widths, repeated and crossed at right angles. The unequal-band-plus-crossing structure is exactly what designers later borrowed the word "tartan" to name.
Mid-20th century — the typographic grid. Josef Müller-Brockmann's Grid Systems in Graphic Design (1981) codified the Swiss grid, including compound grids in which wide content columns are separated by narrow marginal and gutter columns — a tartan in two directions once baseline bands are added.1 Timothy Samara's Making and Breaking the Grid later catalogued these "compound" grids explicitly.8
1961 — Louis Kahn, Richards Medical Research Building. Kahn separated the laboratories (served spaces) from brick service towers carrying stairs and exhaust (servant spaces), making the served/servant distinction the explicit generator of the building.2 Reyner Banham read Richards as services-driven architecture — the servant zones given architectural form rather than buried.7
1965 — Salk Institute. Kahn refined the idea into full interstitial mechanical floors — entire servant bands stacked between the served laboratory floors. Robert McCarter's monograph documents how the section becomes a vertical tartan of served and servant layers.3
Structuralism. Herman Hertzberger's Lessons for Students in Architecture generalised the served/servant band into a teaching principle about giving supporting space its own legible order.4 Francis Ching catalogues the tartan among the standard grid transformations.5
Claims that need qualifying
"Kahn invented the tartan grid." Not quite. Kahn gave the served/servant idea its sharpest architectural expression, but banded grids long predate him in textiles and in proportional systems — Le Corbusier's Modulor already generated a tartan of large and small dimensional intervals.6 Kahn's contribution was conceptual clarity, not the geometry itself.
"A tartan grid is just a structural grid with extra lines." Misleading. The narrow bands are not decoration — they are a functional zone with a job. Remove them and the tartan collapses back into a single-module grid that once again has nowhere to put its services.
"The bands have to be symmetric." No. The wide and narrow bands are deliberately unequal; that inequality is the entire point. A grid of equal bands is just a regular grid.
When to use it (and when not)
| If you want to... | Use the tartan grid | Don't use it for... | Difficulty |
|---|---|---|---|
| Plan a building with heavy services | Servant bands give ducts, risers, and structure a dedicated zone away from the rooms | Simple single-cell spaces with negligible services (use a structural grid) | Intermediate |
| Keep circulation out of the served spaces | Corridors run in the narrow bands so the rooms stay whole | Open free-plan offices where circulation is deliberately fluid | Beginner |
| Lay out an editorial page with strong sidebars | Wide text columns and narrow marginal/gutter columns in a compound grid | Single-column long-form reading (use a manuscript grid) | Beginner |
| Express structure and service as architecture | The servant band becomes a legible, designed element — Kahn's move | Buildings where services should disappear entirely (use a plain grid + ceiling void) | Advanced |
| Coordinate a repeating lab or hospital module | The served-plus-servant unit tiles cleanly down a long plan | One-off bespoke rooms with no repetition | Intermediate |
Famous examples with the overlay applied
Six designs where the wide-and-narrow band rhythm is the explicit organising idea.
Salk Institute (1965)
A vertical tartan: full interstitial mechanical floors (servant) stacked between the laboratory floors (served). The section is the diagram.
Scottish tartan sett
The pattern that gave the grid its name: unequal coloured bands repeated and crossed at right angles to make a plaid.
Swiss editorial grid
Wide text columns separated by narrow gutter and marginal columns — the tartan grid as a page, content bands framed by service bands.
Hospital floor plan
Patient rooms in the wide bands, services and circulation cores in the narrow bands — a tartan because the clinical services demand a dedicated zone.
Modulor dimensional series
The red and blue series interleave large and small intervals — a one-dimensional tartan of φ-derived dimensions long before Kahn named the spaces.
Common mistakes
1
Making the servant band too narrow
A servant band that can't actually hold the corridor, the riser, or the structure it was drawn for defeats the whole point — the services spill back into the served spaces.
Fix: size the narrow band from its real contents (a 1.5 m corridor, a 600 mm duct zone) before fixing the ratio, not the other way around.
2
Using a tartan where a plain grid would do
If the supporting elements are light and can sit anywhere, the second module is dead complexity — narrow bands of nothing breaking up space for no reason.
Fix: only reach for the tartan when the servant elements genuinely deserve their own zone. Otherwise use a single structural grid.
3
Letting the two directions fight
A tartan with an aggressive rhythm both across and down can chop a plan into a confetti of small cells, with served spaces too fragmented to use.
Fix: usually let one direction carry the strong served/servant rhythm and keep the other simpler, so the served spaces stay generous.
4
Treating the narrow band as leftover space
In layout, designers sometimes dump captions, page numbers, and stray notes into the servant columns as an afterthought, and the page reads as cluttered margins.
Fix: give the servant band a deliberate, consistent job — running heads, sidebars, or images — so it reads as designed, not as overflow.
How different disciplines use it
For architects
The tartan grid is the tool for buildings where the services are the problem. Laboratories, hospitals, broadcast and data buildings all generate dense structure, ducts, and circulation that a single-module grid has nowhere to put. The tartan gives them a designated servant band, keeps the served spaces whole, and — done with Kahn's clarity — turns the supporting zone into a legible part of the architecture rather than something buried in a ceiling void.
For graphic designers
In layout the tartan is the compound grid: wide content columns separated by narrow gutter and marginal columns, often with horizontal baseline bands to match. It lets a complex magazine or report hold body text, sidebars, captions, and images in one consistent system. Müller-Brockmann's grids and Samara's compound grids are this idea on the page — content in the wide bands, supporting matter in the narrow ones.
For interior designers
Fitting out a tartan-planned building means reading which bands are served and which are servant, then keeping partitions, joinery, and routes inside the servant zones so the served rooms stay generous. The narrow bands are also where a fit-out can run its own services — power, data, acoustic separation — without disturbing the main spaces.
For students
The tartan grid teaches one of the most useful ideas in planning: that supporting space deserves its own order. Overlay it on Kahn's Richards and Salk to see served and servant made explicit, then try it on a studio project — give your circulation and services a narrow band and watch how much calmer the served spaces become. It is the bridge between a naïve single grid and a genuinely organised plan.
"I do not like ducts; I do not like pipes. I hate them really thoroughly, but because I hate them so thoroughly, I feel that they have to be given their place."
Louis Kahn, lecture (1961)7
Frequently asked questions
What is a tartan grid?
A grid of alternating wide and narrow bands in both directions, so the field reads like a tartan or plaid fabric. The wide bands hold the main content — rooms in a building, text columns in a layout — and the narrow bands hold the supporting elements: structure, circulation, and services in architecture, or gutters and margins in graphic design.
What is a tartan grid in architecture?
In architecture a tartan grid is a compound grid of wide served bands and narrow servant bands — the diagram Louis Kahn used to separate the spaces a building provides from the structure, circulation, and services that support them. It is the architectural sense of the term, distinct from the tartan fabric pattern that gave it its name. Kahn's Richards Medical Research Building is the canonical built example.
What are served and servant spaces?
Louis Kahn's distinction between the spaces a building exists to provide (laboratories, galleries, rooms — served) and the spaces that support them (stairs, ducts, pipes, structure — servant). The tartan grid is the natural diagram for this: wide served bands separated by narrow servant bands.
Tartan grid vs structural grid — how is it different?
A regular structural grid has one repeating bay; a tartan grid has two interleaved modules — wide and narrow — that alternate. The narrow band is a designated zone for the things a single-module grid has nowhere to put: columns, partitions, risers, and circulation. It is sometimes called a double or compound grid.
Where does the name tartan come from?
From Scottish tartan cloth, whose sett is a pattern of crossing coloured bands of differing widths. Graphic designers borrowed the word for grids built from content columns separated by narrower bands, and architects use it for plans built from wide served bays and narrow servant bands.
When should I use a tartan grid?
When the supporting elements deserve their own dedicated zone — laboratory buildings with heavy services, layouts with strong sidebars and margins, or any plan where you want circulation and structure to fall in a consistent band rather than scattered through the served spaces.
Is the tartan grid used in graphic design too?
Yes. In typography a tartan or plaid grid uses wide text columns separated by narrow gutter or marginal columns, often with matching baseline bands. Müller-Brockmann's grid systems and Samara's compound grids both use this band-within-band structure.
Which famous buildings use a tartan grid?
Louis Kahn's Richards Medical Research Building (1961) and Salk Institute (1965) are the canonical examples, with service towers and interstitial mechanical floors as explicit servant bands. The diagram also organises many laboratory and hospital plans.
Can the wide and narrow bands be any ratio?
Within reason, yes. The narrow band only has to be wide enough for its job — a structural line, a corridor, a duct riser, or a layout gutter. Common ratios run from about 3:1 to 6:1 wide-to-narrow, but the right figure is whatever makes the servant band exactly large enough without stealing area from the served space.
References
- Müller-Brockmann, J. Grid Systems in Graphic Design. Niggli (1981). ISBN 3-7212-0145-0.
- Goldhagen, S.W. Louis Kahn's Situated Modernism. Yale University Press (2001). ISBN 0-300-07786-7.
- McCarter, R. Louis I. Kahn. Phaidon (2005). ISBN 0-7148-4045-9.
- Hertzberger, H. Lessons for Students in Architecture. 010 Publishers, Rotterdam (1991). ISBN 90-6450-104-1.
- Ching, F.D.K. Architecture: Form, Space, and Order. 4th ed., Wiley (2014). ISBN 978-1-118-74508-3.
- Le Corbusier. The Modulor. Faber & Faber / Harvard University Press (1954). Translation: de Francia & Bostock.
- Banham, R. The Architecture of the Well-Tempered Environment. Architectural Press / University of Chicago Press (1969). ISBN 0-226-03698-7.
- Samara, T. Making and Breaking the Grid: A Graphic Design Layout Workshop. Rockport (2002). ISBN 1-56496-893-6.
Other Architecture Grids
Notes from the studio · Practitioners on the tartan grid
Illustrative composites of how the tool gets used in practice — not quotes from named individuals.
On lab buildings the servant band is the design. Give the ducts and stairs their own zone early and the laboratories almost plan themselves.
A compound grid is how a complex report holds together. Wide column for the argument, narrow column for the notes — content and support never collide.
Reading which bands are served and which are servant is the first thing I do on a fit-out. Keep the partitions in the narrow bands and the rooms stay generous.
Open the tartan grid overlay
Drop a plan, an elevation, or a layout. The tartan grid applies in one click. Free, in your browser.
Launch Grid Maker Pro →