Departments & Adjacencies

Before you can relate departments, you need to know the cast. A general hospital's departments fall into a few broad groups, and learning the groups is more useful than memorising a list.

Acute diagnostic and treatment - the departments that deal with the sickest, most time-critical patients: the emergency department (casualty), operating theatres, intensive care, and diagnostic imaging (X-ray, CT, MRI). These are equipment-heavy, service-dense and urgent.

Patient care - where patients stay or are seen: inpatient wards, outpatient clinics, maternity, paediatrics, day care.

Clinical support - the engine room that the clinical departments depend on: pathology laboratories, pharmacy, the central sterile services department (CSSD) that sterilises instruments, blood bank, medical records.

Back of house (non-clinical support) - the services that keep the building running: kitchens and dietary, laundry, central stores, engineering and plant, the mortuary, and administration.

> A department is not just a set of rooms - it is a set of relationships to every other department. Planning is managing those relationships.

These groups already hint at the plan. The acute group wants to cluster tightly and sit where ambulances and the public can reach it fast. Clinical support wants to be central and well-connected, because everyone draws on it. Back of house wants its own service circulation, out of sight of patients. Patient care wants daylight, quiet and distance from the noise and traffic of the acute core. A hospital plan is, at heart, the act of giving each of these groups the location its role demands while honouring the specific must-touch links between individual departments, which the rest of this lesson and Module 2 develop.

Among all the adjacencies, one cluster matters more than any other, because lives turn on it. The emergency department, diagnostic imaging, the operating theatres and the intensive care unit form what planners call the hot floor - the acute core of the hospital - and the ideal is to place them so the journeys between them are as short, direct and protected as possible.

Follow a serious trauma case to see why. The ambulance arrives at the emergency department. The patient is assessed and often needs urgent imaging - so a CT scanner sitting within or immediately beside the emergency department, not a lift-ride away, saves critical minutes. If surgery is needed, the patient must reach an operating theatre fast, ideally by a direct, staff-controlled route rather than through public corridors. After surgery, the sickest patients go straight to intensive care. This is the clinical chain - sometimes spoken of in terms of the 'golden hour' - and the planning goal is to collapse the distance and the number of public crossings along it.

There are strong secondary links too. Theatres depend utterly on the central sterile services department for instruments, so CSSD should connect to theatres by a clean supply route and a separate dirty return. The blood bank and pathology should be quickly reachable from both emergency and theatres. Delivery rooms in maternity may need their own theatre for caesarean sections, and a neonatal intensive-care unit nearby.

This is exactly why the planning model of Lesson 1.1 matters: a podium-and-tower concentrates the hot floor on a broad lower level where heavy equipment, structure and services can be provided together, while the calmer wards stack above. Scatter the hot floor across levels or wings and you have lengthened the most dangerous journeys in the building - a flaw that no signage or staffing can fully repair. Note that exact provisions - how many theatres per bed, how close is close enough - are planning judgements to verify against the brief, the casemix and the current standards, not fixed universal numbers.

How do planners capture dozens of these relationships without losing track? With a deceptively simple tool: the adjacency matrix (also called a proximity or relationship matrix). List every department down the rows and across the columns, and in each cell record how strongly those two departments need to be near each other - typically on a scale such as essential (must be directly connected), important (should be close), desirable (helpful), neutral, and undesirable (should be kept apart, like kitchen and mortuary, or clean supply and waste).

The matrix is powerful for three reasons. First, it forces the clinical team and the architect to state and agree every relationship explicitly, rather than discovering conflicts late in a plan. Second, it exposes the heavily-connected 'hub' departments - imaging, CSSD, pathology - that should sit centrally because so much depends on them. Third, it turns directly into geometry: the essential links become a bubble diagram, where each department is a circle sized to its area and joined to its must-touch neighbours by lines, which you then push and pull until the strongly-linked ones cluster and the incompatible ones separate. The bubble diagram, stacked across floors, becomes the block plan - the first real plan of the hospital.

RELATIONSHIP SCALE (typical - agree yours with the clinical team)
  E  essential   - must be directly connected
  I  important   - should be close / same level
  D  desirable   - helpful if convenient
  .  neutral     - no strong need
  X  undesirable - must be kept apart (clean/dirty, noise, dignity)

The matrix also records the negative adjacencies, which matter as much as the positive ones: the kitchen must not open onto the mortuary; the public entrance must not pour into clinical zones; clean supply and clinical waste must never share a route. In this sense the adjacency matrix is where the separation of clean and dirty - the governing principle of the whole course - first enters the plan as explicit, checkable rules. It is low-tech, it fits on a page, and it is one of the most important documents a hospital planner produces.

No real building satisfies every adjacency perfectly, because many of them compete. Imaging wants to be beside both the emergency department and the outpatient clinics, which may sit far apart. Theatres want to be near emergency, intensive care, maternity and CSSD at once. On a constrained site or within a fixed massing you simply cannot grant every essential link, so planning becomes the disciplined art of ranking and trading: which adjacencies are genuinely life-critical and must be honoured, and which can be softened - by a dedicated lift, a duplicated facility, or a slightly longer but protected route.

This is where the planner earns their keep. A well-placed dedicated bed-lift can make a vertical adjacency behave almost like a horizontal one. A satellite facility - a small imaging room inside the emergency department in addition to the main imaging suite - can resolve a link that geometry cannot. A decision to co-locate maternity's theatre rather than share the main theatre suite trades floor area for safety and flow. Every one of these is a reasoned trade-off recorded against the matrix, not an accident, and the matrix is precisely what lets you defend each choice later - to the clinicians, the accreditation body and the client - because the logic behind every placement is written down. When a link cannot be granted at all, the honest planner names it as a residual risk to be managed operationally rather than quietly burying it in the plan.

The adjacency work also sets up the next two lessons. Once departments are placed, the flows between them - patients, staff, supplies, clean and dirty - must be routed so the right things meet and the wrong things never cross (Lesson 1.3). And the whole arrangement must sit on a grid disciplined enough to let departments expand into one another as the hospital changes (Lesson 1.4). Adjacency is the bridge from the abstract model to the living, flowing building.

Treat published adjacency diagrams and schedules of accommodation as starting templates, not gospel: your casemix, your site and your clinical team will reshape them. The method is universal; the specific arrangement must be verified against the brief, the health authority's requirements and the current code in every project.