What followed was the most fascinating few months of building research. This week the report surfaced again and through a different lens I looked at the project in a new way – this time through the lens of sustainability.

When sustainability in the built environment is discussed, the focus often falls on new developments, innovative materials, and energy-efficient technologies. While these are undoubtedly important, one of the most effective sustainability strategies is often overlooked: preserving and extending the life of existing buildings.

18 Crown Passage, St James’s, London is a remarkable example, a building that has stood continuously since the 1670s and remains in active use today. More than 350 years after its construction, this modest property demonstrates how historic buildings can deliver lasting environmental, social, and economic value.

A Building That Has Already Passed the Ultimate Lifecycle Test

Completed in 1676, 18 Crown Passage has survived fires, industrialisation, world wars, technological revolutions, and dramatic social change while continuing to serve the community around it. Originally constructed as a house, it has adapted over time to accommodate a range of uses, from residential occupation to commercial activities supporting the renowned hatmakers James Lock & Co.

Its story highlights a key principle of sustainable construction: the greenest building is often the one that already exists.
Modern sustainability assessments increasingly recognise that the environmental impact of a building extends far beyond operational energy. The extraction of raw materials, manufacturing of products, transportation, construction activities, and eventual demolition all contribute to a building’s embodied carbon footprint.

By remaining in use for more than three centuries, 18 Crown Passage has effectively spread the carbon emissions associated with its original construction across generations of occupants, dramatically reducing its lifecycle environmental impact.

Fairthorne and Newcourts map 1643-7                

Blome’s map 1689; the parish of St James

Preserving Embodied Carbon

Every brick, timber beam, lime mortar joint, and floorboard within a historic building represents carbon that has already been invested.

Demolishing a building prematurely not only wastes this embodied carbon but typically creates additional emissions through demolition activities, waste transport, and the construction of a replacement building.

At 18 Crown Passage, many original materials remain in service today, including substantial areas of historic brickwork, timber structure, and traditional construction elements.

From a carbon perspective, retaining these materials avoids the emissions that would otherwise arise from:

• Producing new structural materials.
• Transporting those materials to site.
• Construction and installation activities.
• Waste disposal and processing of demolished materials.

As organisations seek pathways to net zero, extending building life is increasingly recognised as one of the most effective means of reducing whole-life carbon emissions.

Using locally sourced materials and labour

Prioritising locally sourced materials in the 1670s was generally a given. Whilst some materials such as timbers were sourced from outside of London, these were transported without the use of burning fossil fuel.

Of course, some fuels were used such as for the firing of bricks. Yet the bricks themselves would have been made from local clay and London Brick earth; a layer of dust that drifted across London around 25,000 years before. This pre-history of London highlights an interesting connection between the geology of St. James and the fabric of 18 Crown passage – built tens of thousands of years later.

It is known that bricks of this period were largely produced local to the site, but brickfields were in existence and the deciding factor of brick supply was the cost of transportation and local availability at a time of high demand.

The earth excavated from construction of a basement was sometimes used in the construction but otherwise spread evenly on the bordering roads, raising their level. Foundations of rammed earth or maybe ash were usually laid to support stepped brickwork footings. This formed the base for the walls, which the bricklayers tended to build simultaneously so as to load the foundations evenly.

Brickwork was laid with the use of lime mortar, traditionally mixed with earth, clay or maybe dung to improve adhesion. The lime has a quality that draws and sequesters carbon from the atmosphere for decades or even centuries as CO₂ slowly penetrates further into the mortar.

Lime was produced from chalk and imported in large quantities into London at that time, chiefly from Greenhythe in Kent where the chalk hills were easily accessible and close enough to the river for transportation. Testament to the quantity of chalk quarried for this purpose can be seen by the size of the quarries at Greenhythe, one of which now houses the Bluewater Shopping Centre; built as Europe’s largest.

Historic Buildings as Carbon Stores

Many historic buildings also act as long-term carbon stores.

At 18 Crown Passage, the timber joists, floor structures, partitions, doors, and other wooden elements have been locking away carbon for centuries. Georgian homes often sequestered carbon in the use of around 30 mature trees in their construction.
When buildings are maintained and adapted rather than demolished, this stored carbon remains safely sequestered within the structure. In contrast, demolition can release a proportion of this carbon back into the atmosphere, particularly where materials are incinerated or otherwise degraded.

This is a powerful reminder that conservation is not simply about protecting heritage. It is also about protecting carbon already captured from the atmosphere.

Adaptability Is Sustainable Design

One reason 18 Crown Passage has survived for so long is its adaptability.

Over its lifetime the building has evolved from a residential property to a mixed-use commercial space, accommodating changing economic and social needs without requiring wholesale reconstruction. Alterations such as new services, shopfront modifications, and internal upgrades have enabled continued occupation while retaining much of the original structure.

This flexibility represents a fundamental principle of sustainable building design.

Buildings that can be adapted for new purposes have the potential to remain useful for generations. By contrast, buildings designed with limited flexibility can become obsolete, leading to costly refurbishment projects or complete replacement.

Delivering Social Value Through Heritage

The benefits of preserving historic buildings extend beyond carbon savings.

Buildings like 18 Crown Passage provide a tangible connection to local history and identity. Its story reflects the development of St James’s from open farmland into one of London’s most influential districts, while the property’s long association with tradespeople, residents, retailers, and the celebrated hatmaker Lock & Co. illustrates the changing social and economic life of the capital.

Historic buildings contribute social value by:

• Preserving cultural heritage.
• Supporting local character and sense of place.
• Creating attractive and distinctive environments.
• Providing educational opportunities.
• Strengthening links between communities and their history.

In an era when many urban environments can feel increasingly uniform, historic buildings offer authenticity that cannot be replicated through new construction alone.

Amongst the long history of the building is the ownership by Lock and Co and their invention of the Bowler Hat, although at Lock’s they refer to it as the ‘Coke’ after the customer that commissioned it rather than by the name of the manufacturer that was appointed to produce it; Bowler. History of this type enhances social value.

Each building has a story – it connects us.

The metropolitan archives (ref B/LK) have order and day books from James Lock and Co that date back over the centuries; their customer list clearly represents royalty, politics, the military and international celebrity for any given period of their history; names such as Charlie Chaplin, Lawrence Olivier, Montgomery, Duke of Wellington, Bob Hope, Lord Lucan, Sinatra, Churchill, Jackie Oanasis, Oscar Wilde, The Queen.

One of the last tasks Nelson attended to before leaving England for the battle of Trafalgar, and ultimately his death, was to settle his bill to date at Lock’s (£11 19s 6d), which included his last cocked hat and eyeshade that he’d ordered three days previous.
20 years ago, to give myself a flavour of the kind of hats that sat in boxes to await despatch at Crown passage, I remember scanning through their visitor’s book with considerable interest. Visitors since 1900 had included; Prince Charles, Stephen Fry, Noddy Holder, Sarah Ferguson, Michael Portillo to name just a few. And Jeffery Archer, who’d cleverly written ’just stole a hat!’ in the comments section; a comment that he may not have had the bravado to write if he’d known that a perjury trial and prison lay several years ahead. Paul McCartney’s signature lay just above Jimmy Tarbuck’s who’d inserted a small arrow pointing up to McCartney’s name with the comment, ’used to listen to him when I was a kid!’

In more recent times Bowler hat is still made, yet for a different clientele. Recent orders include Chris Eubanks, Mike Tyson and rap star, Puff Daddy.

When the project began I’d had some expectation of discovering some of the property’s history. In the event, the property yielded a considerable story. The 1670s, when its story began, are almost incomprehensible compared with modern day living; an age before many of the things that we now consider mandatory, before the progression of medicine, industrialisation, mass transportation, consumerism, the United States of America… even 150 years before cockney rhyming slang first appeared. Yet the property stands much as it did then; unaffected by world circumstances, war or crisis.

And the property’s use continues. It may be that in it’s connection with hat making its dealing with tomorrow’s Charlie Chaplin or Lord Lucan; and in this way it seems that the history of 18 Crown Passage is still being written.

A Sustainability Strategy Hidden in Plain Sight

The story of a buildings use and its construction go hand in hand. 18 Crown Passage demonstrates that sustainability is not always about building more. Sometimes it is about caring for what we already have.

By maintaining and adapting existing buildings, we can:

• Avoid significant embodied carbon emissions.
• Preserve valuable carbon-storing materials.
• Reduce demand for new construction products.
• Minimise construction waste.
• Protect cultural and social heritage.
• Extend the useful life of built assets for future generations.

More than 350 years after its construction, 18 Crown Passage continues to serve a purpose. Its longevity reminds us that truly sustainable buildings are not simply those designed for today’s standards, but those capable of remaining useful, adaptable, and valued for centuries.

For building owners, developers, and occupiers alike, the lesson is clear: retaining and enhancing existing buildings is often one of the most powerful sustainability decisions we can make.

Source: Historical information derived from The History of 18 Crown Passage, London by Stan Rayfield (2006).

By Fathima Sumayya

In the race to become ‘net zero’, more and more companies are turning to carbon credits to offset their emissions. On paper, it sounds like a win: emit carbon here, pay someone to reduce it somewhere else and you’re off the hook.

But let’s pause for a reality check…

Behind many of these offset purchases is a different story- one that’s not shared in glossy sustainability reports or corporate websites. It’s a story where ambitious net-zero targets quietly become unachievable and instead of changing how business is done, companies reach for their wallets. No talk of reducing flights, switching to renewables or rethinking their supply chain. Just an expensive offset, likely bought as a last-minute fix.

So, where’s the problem?
When companies skip the hard work and buy their way to “net zero” they’re not solving the climate crisis- they’re outsourcing responsibility. It sends a dangerous message: that climate action can be bought not earned.

Let’s ask a few uncomfortable questions:
• Could everyone carry on polluting at the current rate and just offset?
• Could there ever be enough offsetting to go around?
• Could offsetting work in time to solve the climate crisis by 2050?

The answer, simply, is no.

Offsetting is limited- not just in scale, but in time. Trees, for instance, can take anywhere between 40 and 100 years to absorb the carbon we’re emitting today. We don’t have that long. The climate crisis is urgent, and the clock is ticking.

Even if we planted every available tree, there wouldn’t be enough land or time to balance out the current level of global emissions. In other words: offsetting is not a plan- it’s a stall.

The UK’s Climate Change Committee (CCC) has been clear on this. In their ‘Balanced Pathway’ scenario for reaching net zero by 2050, the CCC found that the vast majority of emissions reductions must come from direct action- within sectors, within companies, within supply chains. The CCC sees carbon offsetting as a last resort for emissions that are impossible to eliminate, not as a replacement for real, sustained internal change

When credits are used as a shortcut instead of a supplement, it’s not climate leadership- it’s greenwashing.

Lets be clear here, what does net zero actually mean?
Real net zero means real change in how a company operates.
It means challenging questions: Can we travel less? Can we reduce waste or procedure goods with less embodied emissions? Can we use sustainable energy? Can we use sustainable energy?

And no, it does not mean continuing with business-as-usual and cutting a cheque to look clean on paper.

What should businesses aim for?
• Transparency: If you’re buying offsets, be clear about how much you’re reducing internally vs how much you’re offsetting.
• Priority to internal reduction: Don’t just rely on credits, demonstrate real change within your operations.
• Long-term vision: Sustainable business is not about quick wins. It’s about building a resilient, responsible organisation.

Let’s shift the focus from offsetting to owning emissions. That’s where real impact lies.

Public open spaces, those havens of green amidst the urban jungle, are more than just places to relax. They’re vital components of a thriving, sustainable city, contributing to a healthy environment, a strong community, and a happy populace. In a world striving to achieve the UN’s Sustainable Development Goals (SDGs), green spaces are emerging as a powerful tool.

Greener Cities, Healthier People (SDG 3: Good Health and Well-being)

Imagine a city where parks are plentiful, offering residents a chance to escape the concrete and reconnect with nature. Studies show that access to green spaces encourages physical activity, reduces stress, and even improves cognitive function. This translates to a healthier population, aligning with SDG 3. Public spaces promote walking, cycling, and outdoor games, all contributing to a drop in non-communicable diseases.

Parks for People, Power for the Planet (SDG 11: Sustainable Cities and Communities)

Green spaces go beyond personal health. They play a crucial role in creating sustainable cities, as highlighted by SDG 11. Trees and plants act as natural filters, absorbing pollutants and releasing oxygen, leading to cleaner air (SDG 13: Climate Action). They also help regulate urban heat islands, a growing concern in a warming world. Additionally, well-designed green spaces can manage stormwater runoff, preventing flooding (SDG 6: Clean Water and Sanitation).

Building a More Equitable City (SDG 5: Gender Equality)

Green spaces aren’t just good for the environment; they foster social cohesion too. Parks and plazas become vibrant community hubs, bringing people together from all walks of life. This is particularly important for women and girls (SDG 5: Gender Equality). Safe, well-lit public spaces empower them to move freely and participate in community life, fostering a sense of security and belonging.

Growing Economies with Greener Cities (SDG 8: Decent Work and Economic Growth)

The benefits of green spaces extend to the economy as well (SDG 8: Decent Work and Economic Growth). Studies have shown that areas with ample green space have higher property values and attract tourism. Public spaces can also provide valuable workspaces for informal vendors, contributing to the local economy.

The Path Forward: Prioritising Green

The solution lies in recognising the multifaceted value of green spaces and integrating them into urban planning. Cities need to prioritise creating and maintaining parks, playgrounds, and green corridors. This can involve innovative solutions like rooftop gardens and vertical forests.

By embracing green spaces, cities can become healthier, happier, and more sustainable places to live. Public open spaces are not a luxury; they’re an investment in our future and a key to achieving the SDGs for a better world.

Using the secondary benefits of careful lighting control can be a driver to energy reduction. Favouring and maximising natural daylight in office spaces can not only lead to office workers being more productive, but also improving well being.

What are the 5 key benefits to maximising natural daylight?

1. Increased alertness: Exposure to natural light helps regulate the body’s internal clock and promotes wakefulness. This can lead to improved focus and alertness among office workers.
2. Mood enhancement: Natural light has a positive impact on mood and can reduce feelings of stress and anxiety. A pleasant working environment with ample daylight can contribute to a more positive and productive mindset.
3. Better sleep quality: Exposure to natural light during the day helps regulate the body’s sleep-wake cycle. When office workers have better sleep quality, they are more likely to be well-rested and perform better during working hours.
4. Improved cognitive performance: Studies have shown that natural light can enhance cognitive function, including memory, attention, and problem-solving skills. This can lead to higher productivity and efficiency in completing tasks.
5. Eye health: Adequate natural light can reduce eye strain and the risk of developing certain eye conditions associated with poor lighting, such as eyestrain, dry eyes, and headaches.

To maximize the benefits of natural light, office spaces are often already designed with large windows. However, many windows are often obscured by blinds at times when neither heat or glare needs to be reduced. Having a strategy of when to use the blinds and when not to, can enhance the level of natural daylight and reduce the need for artificial light.

Setting intelligent lighting system in zones away from sources of natural light can dim lighting when light levels are adequate, and using light-coloured walls and reflective surfaces can help distribute natural light throughout the space.