Unpacking Ulrich 1984: Plants in Healthcare

Roger S. Ulrich, PhD, is likely the most cited and influential evidence-based healthcare design researcher in the world. His studies have been praised for their scientific rigour (you'll see why when we dive into the study), and his findings are implemented by healthcare managers, clinicians, design practitioners, and policymakers around the world.

Ulrich's work has greatly influenced the design of many billions of pounds in hospital construction, particularly in leading hospitals to provide a greater connection to nature. It has also improved patient safety and health outcomes worldwide.

His seminal work was a piece of research titled View through a Window May Influence Recovery from Surgery.

The research is a study in environmental psychology that demonstrated the impact of natural views on patient recovery. Ulrich investigated whether views of nature could positively influence recovery outcomes for hospital patients.

The Basic Premise

Ulrich wanted to see whether patients who had a view of trees from their hospital window recovered better than those who had a view of a brick wall.

The views likely looked like this:

A view of green, leafy trees from inside a room

A view of a brown brick wall from inside a room

Ulrich didn’t provide pictures, so these are not the actual views but are representative of how the view was described in the study.

I’m sure all of us would prefer the view of trees; however, what Ulrich wanted to find out is whether the view made a statistical difference. It was the first experiment of its kind.

How Ulrich Carried Out His Study

For Ulrich, ensuring control was the most important aspect of the study.

The first part was selecting the hospital. He carried out extensive searches and chose a 200-bed suburban facility in Pennsylvania – the hospital isn’t named as far as we know.

This hospital was picked because it had just the right layout for his study: one wing had rooms that were almost identical in size and arrangement, with the only difference in patient experience being the window view.

The study included 46 patients over a nine-year period, and the two views were either a small stand of trees or a view of a brown brick wall.

The Controls

Ulrich was extremely careful to ensure his experiment was well controlled. He put in place several controls:

First, he matched the patients to make sure there were no other factors at play. He matched them for sex, age (patients were within a 5-year age range), smoking status, weight, and general health history, especially considering previous hospitalisations.

He also matched the year of surgery; this was important as Ulrich’s study was carried out over a nine-year period, so it was essential to ensure that medical practices or technology hadn’t changed significantly.

Next, he made sure that everyone he included in his study had exactly the same surgery, which was a cholecystectomy (gallbladder removal). This was to minimise variation in recovery processes and outcomes.

It was then critical that the other variables in the environment were controlled, so the rooms were identical in size, furniture arrangement, and location (within the same wing), ensuring the only significant variable was the window view (trees vs brick wall). Ulrich also controlled the room colour on the second floor, matching blue and green rooms.

The study only included surgeries performed between May and October, the months when the trees outside the hospital had full foliage.

It was essential for Ulrich to exclude patients who were under 20 or over 69 years old, had developed serious complications, or had a history of psychological disturbances, to make sure the results weren’t skewed by these factors.

Finally, recovery data, such as duration of hospital stay, medication usage, and nurses’ notes, were collected by a nurse who was unaware of the patients’ room views, reducing the potential for bias in data recording.

These controls were put in place to isolate the effect of the natural view on patient recovery, ensuring that differences in outcomes could be attributed with greater confidence to the influence of nature rather than other variables.

The Results

Now for the interesting part! The results are broken down into the four key areas below, and then summed up in one neat paragraph.

Length of stay

Patients who had a view of trees recovered faster than those who faced a brick wall. On average, tree-view patients stayed 7.96 days, while wall-view patients stayed 8.7 days, showing a statistically significant difference in recovery time.

Medication usage

During the critical post-surgery period (days 2–5), tree-view patients received significantly fewer moderate and strong doses of pain relief than wall-view patients, indicating less perceived pain and discomfort.

Nurses’ observational notes

Nurses recorded more positive comments for patients with tree views and fewer negative comments compared to those facing the brick wall:

• Positive notes (e.g., "in good spirits" or "moving well") were more frequent for tree-view patients, while negative notes (e.g., "upset and crying" or "needs much encouragement") were higher among wall-view patients.

• Specifically, the tree-view group had an average of 1.13 negative notes per patient, whereas the wall-view group had 3.96 negative notes per patient, showing a significant emotional and mood-related difference between the two groups.

Minor postoperative complications

Patients with a natural view had lower scores for minor complications such as headaches and nausea, although this difference was not statistically significant. The reduced complications in the tree-view group could be linked to their reduced need for strong pain medications.

Results Summary

Ulrich’s study concluded that natural views significantly improved recovery outcomes by reducing the length of hospitalisation, decreasing the use of strong pain medications, and positively influencing mood and behaviour as observed by nurses.

These findings supported the hypothesis that access to nature has therapeutic effects, laying the groundwork for the concept of evidence-based design in healthcare facilities.

Our Thoughts

At Plant Plan, we think there’s greater scope for indoor planting in healthcare environments. While it’d be amazing to fill hospitals with plants, we have to consider the spread of infection in hospitals and the difficulty of cleaning plants.

With that consideration, there are various ways that biophilic design could be implemented in healthcare environments.

This first suggestion is my favourite, and it’s an idea I stole from a project we completed in an office in central London. In this office, we integrated planting within a false wall, using reeded glass to partially obscure the view. This created the impression, from inside the room, of looking out into a rainforest, with plants appearing to press against the glass.

It’s a great way of incorporating biophilia while still having easily wipeable surfaces. It also gives the impression of natural light, despite it being artificial.

Another option is to create a biophilic room that utilises advanced cleaning methods, such as fogging. While this approach may not be practical throughout an entire hospital, specific rooms or areas could adopt this cleaning routine, given the positive impact it could have on patient recovery and mental health. This would be particularly beneficial for patients who cannot easily go outside, such as those who are frail or have weakened immune systems.

The next idea to consider is indirect biophilia, particularly using natural analogues like natural materials, patterns, and textures.

Natural materials like timber are being used more commonly for construction, and also as a finish. Whether or not wood is suitable from an infection control perspective would have to be reviewed by an expert in the field; however, it doesn’t stop natural colours, shapes, and patterns from being used.