How many office plants do I need?

According to the original WELL Building Standard, 2 plants per 100m² for office space, and 30 plants per 100m² of restorative space. However, the more important factor is having plants in employees’ sightlines. WELL V2 has moved away from quantitative requirements.

It’s a question I get asked all the time whilst I’m out talking with designers and clients.

You’ve told us all about plant benefits, so surely there must be a certain amount we need to achieve the benefits?

The answer is, there were statistics, but they're perceived as less important than they were.

The original WELL Building Standard, written by the International WELL Building Institute, contained Feature 100: Biophilia II – Quantitative which required a minimum of 1% of floor space, or 2% of wall or ceiling space, and then 15% in restorative spaces such as breakout areas, canteens, etc.

If you had a 100m² office space, which would fit around 14 people based on commonly accepted metrics of 7m² per person, and a 10m2 canteen, you’d need 1m² of planting for the office (approximately 2 medium-sized floorstanding plants at 0.5m² each), and 1.5m² of planting for the canteen (approximately 3 medium-sized floorstanding plants at 0.5m² each).

Those are the official statistics, however, realistically, two plants in an office of 14 people would certainly look underwhelming and is unlikely to result in the significant productivity and creativity output, and stress reduction you’re looking for.

This is backed up by the fact that WELL V2 has moved away from giving specific quantities for plants. The focus has shifted to qualitative aspects under Feature 88: Biophilia I – Qualitative. This emphasises integrating biophilic design through natural elements, patterns, and interactions, with no specific quantitative requirements for plant coverage.

The current WELL Building Standard still recommends that workers are within 33ft or 10 metres of a plant or views of nature.

This demonstrates that more important than percentage of floorspace covered is ensuring that each worker has a sightline of a plant from their desk. The plants that have the impact are the plants that you can see.

To take this point a step further, we have to consider the effect plants have on air quality. There are competing studies on this point, for example, Professor Dr Tove Fjeld’s 1990s studies clearly demonstrate across three different studies that plants have an impact on physical health, particularly in relation to air-quality related symptoms (I’ve linked an extensive review I wrote of her study here).

The other study that suggests plants don’t have an impact on air quality is one by Cummings & Waring in 2019 that posits that the natural or mechanical rate of air change is so high that plants won’t have an appreciable impact on air quality. They suggest that to achieve genuine air purification results you’d have to have 10 - 10,000 plants per m², however, the huge range casts doubt on the claim.  That having been said, the suggestion that plants are unlikely to have a significant effect on air quality without a reasonable density of plants is a fair point.

Fjeld’s suggested that in her studies the plants were close to the participants could be a reason for their effect on the individual’s health as plants would increase local humidity and air cleanliness.

As a plant guru, what would you recommend for office planting?

I'm not a fan of the 1-2% rule, I think it provides an arbitrary limit which can result in quite an underwhelming design. Most successful planting schemes exceed these percentages by some way - a couple of pot plants to achieve 1% just feels a bit token and isn't going to have a meaningful impact.

Here's what I'd recommend instead:

Consider allocating one plant per desk (they don't have to be on the desks): This volume should ensure every employee has a sightline to greenery, amplifying mental health and productivity benefits.

Clusters in breakout spaces: create lush, restorative areas where employees can recharge. Think dense clusters of plants rather than sparse arrangements.

Prioritise visual impact: instead of scattering tiny pots, invest in statement floorstanding plants or planted troughs to create an immediate wow factor.

Don’t overthink air purification: think of plants as a bonus for local air quality—not a replacement for proper ventilation.

It's worth bearing in mind that what works well for a small office doesn't necessarily translate well for a big office, and vice versa.

For example, in a small office, pot plants along shelving or windowsills or on desks can work very well, however, this can quickly translate into an unmanageable volume of plants if the same approach is taken in a large space.

A small office may also be able to manage the plant maintenance themselves, whereas in a larger corporate environment, it's more common (and more successful) to have a maintenance service.

In larger offices, there's greater scope for larger installations, such as bespoke joinery items which allow for lush planting with lots of depth and variety. You could also consider living walls to create immersive natural spaces.

It's worth bearing in mind cost when deciding on your office plant volume.

You might like the idea of filling your space, with plants, however, the cost could seem prohibitive with an average floorstanding plant costing around £470. However, like many other planting providers, we have a plant rental scheme that starts at £58/week and would equate to approximately 12 floorstanding plants.

Moving to bespoke items, such as joinery pieces, living walls, and more come with higher prices, but do dramatically increase the visual impact of the planting.

The right number of plants isn’t about ticking boxes—it’s about creating an environment where greenery feels abundant and impactful. While the WELL Building Standard offers helpful benchmarks, the real measure of success is whether every employee can look up from their desk and see something green.

By focusing on sightlines, density in key areas, and visual impact, you’ll create a workspace where both employees and plants thrive.