Green space has moved from a nice-to-have to a non-negotiable in office design, and that shift was the starting point for the latest BCO NextGen London SE event, part of the “Let’s Talk About It” series.

Hosted by Tom Buckley, partner at Core Five, the panel brought together Morgan Taylor, director at environmental consultancy Greengage Environmental, James Hanton Parr, development manager at V7, and Jennifer Mui, director and landscape architect at MRG Studio. Between them they covered the policy, the plant science and the pounds and pence of putting genuine biodiversity into commercial buildings.

Buckley opened by framing the shift bluntly: green space is no longer a question of whether to include it, but how to deliver it in a way that is measurable, meaningful and good value.

“The challenge for us is no longer where green spaces should be included,” said Buckley, “but how we deliver it in a way that’s meaningful, measurable and generally valuable for all.”

Two acronyms dominated the policy discussion: Biodiversity Net Gain (BNG) is now a legal requirement for most new developments, mandating a minimum 10% uplift in biodiversity value versus the pre-development baseline, calculated through a standardised metric. The Urban Greening Factor (UGF), by contrast, is not comparative and not universally mandatory; it sets a target score for the greening delivered on a scheme and is currently a London-specific tool, albeit one some boroughs, including the City of London, are moving to strengthen through unit-per-hectare targets.

Greengage’s Taylor was candid that both figures have shakier origins than most practitioners assume; the 10% BNG uplift and UGF’s 0.3–0.4 targets emerged from feasibility work rather than robust evidence, and BNG exemptions have recently been widened rather than tightened. Even so, the panel agreed the metrics have value: they replace subjective haggling over planning conditions with a consistent, harder-to-value-engineer baseline.

A recurring theme was the gap between what gets approved on paper and what actually survives on site. Taylor cited borough-level monitoring showing that roughly three-quarters of delivered green roofs failed to meet their planning objectives, typically because substrates were installed too shallow to sustain planting – turning living roofs into fire-risk kindling rather than functioning habitat.

MRG’s Mui and Taylor both argued for moving away from monocultural sedum roofs and manicured, heavily-irrigated planting towards biodiverse, stress-tolerant “matrix” planting modelled on habitats such as chalk grassland or brownfield sites – schemes that are more resilient to heat and drought, cheaper to establish, and score better against both BNG and UGF.

On the business case, Hanton Parr was clear that outdoor amenity now sits at or near the top of occupier priorities. Investors see a rental and asset-value premium attached to well-designed terraces, and green finance is starting to reinforce the trend directly. GPE’s credit facility, linked to BNG performance across its portfolio, was cited as an example of biodiversity commitments translating into more favourable lending terms.

“Green spaces and terraces form a big part of what makes buildings special for us,” said Hanton Parr.

Practical delivery constraints ran through the discussion: structural loading and soil depth, the balance between capital cost and long-term maintenance, fire safety, irrigation and access for upkeep. Mui stressed that terraces need to be designed as varied, usable spaces, for a quiet lunch as much as a summer party, not just expanses of “occupiable” square metreage.

Panellists agreed the biggest single lever for cost-effective biodiversity is dense, varied planting from the outset rather than a handful of statement trees; accepting a higher initial plant mortality in exchange for scale and diversity was described as the more economical route to a thriving, low-maintenance landscape over time.

The closing message to developers was to engage landscape and ecology expertise early and with an open brief, rather than defaulting to what has been delivered on the last five schemes.

As policy tightens further and occupier expectations rise, panellists were clear that genuinely biodiverse, well-maintained green space is fast becoming a core differentiator for prime office space, not a compliance afterthought.

FIVE KEY TAKEAWAYS

1. Design for both metrics from day one: Biodiversity Net Gain and the Urban Greening Factor measure different things. Factor both into viability and structural/drainage strategy at the earliest stage, not once planning is underway.
2. Ditch the monoculture: Sedum blankets and amenity grass score and perform poorly. Biodiverse, stress-tolerant planting modelled on chalk grassland or brownfield habitats is cheaper to sustain, more climate-resilient and scores higher on both BNG and UGF.
3. Substrate depth is where schemes fail: Monitoring suggests a large majority of delivered green roofs in some boroughs don’t meet planning objectives, largely due to under-specified growing media. Check this at the detail design and inspection stage, not just at planning submission.
4. Amenity space now drives value, not just compliance: Well-designed, biodiverse outdoor space is now a top occupier priority across London and major regional markets, commands a rental and asset-value premium, and is increasingly linked to green finance terms.
5. Build in time and maintenance, not just capex: Dense, varied planting with accepted early mortality often beats fewer ‘showpiece’ specimens on cost and biodiversity outcomes, but landscapes need time to establish, and maintenance access and budget must be planned in from the outset.

Thanks to Core Five for hosting, our panel for sharing their intelligence and insights, and to Planteria for providing  beautiful plants for all attendees.

Good landscape design – in and outside of your workspace – is social infrastructure. Getting it right can support mental health, reduce stress, improve navigation, encourage civic life and unlock wider investment.

This was the topic of discussion at a recently hosted BCO Scotland event that brought together Greg Meikle, regional director at OOBE, Gordon Yeaman, director at MLA and Cameron Kerr’s Bernie Carr, to argue that biophilic design is so much more than just the introduction of plants into buildings.

A recurring theme was that landscape and external environment should not be treated as an afterthought, with the panel arguing that public realm, planting, views, daylight, thermal comfort and access to nature all influence how people experience buildings and cities.

The speakers challenged the idea that indoor planting alone delivered biophilic outcomes.

Plants can help, but only when the underlying environmental “canvas” is right. However, offices are often highly artificial environments: fixed temperatures, fixed lighting levels and controlled airflow.

Proper biophilic design requires more dynamic, naturalistic conditions, including daylight variation, air movement, material texture, views, seasonal change and opportunities to move between different environments.

The debate also connected biophilic design with trauma-informed design, with the panel highlighting how external routes, thresholds, wayfinding, colour, material changes and safe arrival sequences can materially affect whether people feel able to access a building. In healthcare and education contexts, better-designed environments were said to contribute to fewer missed appointments and reduced pressure on services.

 Another strong thread throughout the conversation was measurement. The panel acknowledged that the sector was good at measuring isolated components such as canopy cover, light levels or floor area, but much less effective at measuring lived experience. Post-occupancy evaluation was identified as essential, particularly if designers want to prove that early investment in landscape, public realm and environmental quality creates real value.

The discussion concluded with a focus on Glasgow and Scotland more generally. The panel suggested that Scotland was still behind parts of England and Europe in treating landscape and public realm as a primary driver of development quality. Projects such as George Square, the Avenues and the Clyde were discussed as opportunities to use landscape, water, biodiversity and “meanwhile” interventions to make the city centre healthier, more attractive and more investable.

Top ten takeaways

1. Biophilic design is not just plants
   It includes daylight, air movement, thermal variation, natural materials, views, smell, sound, texture, seasonality and people’s emotional experience of space.
2. Landscape must be involved from day one
   Leaving external space until the end usually reduces it to “green sauce” rather than a meaningful part of the development strategy.
3. The base environment matters before decoration
   A rigid, sealed, artificially lit office cannot become genuinely biophilic simply by adding planting.
4. Real plants outperform artificial ones
   Their value is not only visual. They change, grow, support air quality, create moments of attention and give people a sense of living connection.
5. Experience is harder to measure than cost, but no less important
   The panel called for better post-occupancy evaluation to understand how spaces are actually used and felt.
6. Biophilic design can support trauma recovery and accessibility
   Safe routes, clear thresholds, intuitive wayfinding and softer sensory environments can reduce anxiety and help people feel able to enter and use buildings.
7. Choice is critical
   People need different types of space: light and dark, open and sheltered, social and quiet, warm and cool.
8. Thermal variation can be positive
   The panel discussed “thermal alliesthesia”: the pleasure and stimulation people can feel from moving between different thermal conditions rather than sitting in one fixed temperature all day
9. Public realm investment can unlock wider value
   Good streets, squares, green spaces and riverfronts can improve wellbeing while also encouraging commercial and civic investment
10. Scotland needs to treat landscape as social infrastructure
    The strongest closing point was that biophilic and landscape-led design should be outcome-based, strategic and embedded early, not treated as optional aesthetic enhancement.

If you’d like to find out more about the BCO’s events, check out our calendar here: https://www.bco.org.uk/events