London Homes Are Overheating — But We Can Design Our Way Out of It

Earlier this week, I sat down with BBC London’s Alice Bhandhukravi for an interview about a growing issue that’s impacting homes across the capital — and shaping the way we design. While my contribution was a small part of the final broadcast, we spoke for nearly an hour about overheating in London’s homes, why it’s happening, and what we can do about it.

At RISE, we’ve been working with homeowners and developers to tackle this very issue — not just with technology, but with thoughtful, resilient design that makes homes genuinely comfortable to live in.

Sean Ronnie Hill, Director and Architect at RISE Design Studio, interviewed by BBC London on how better design can help London homes beat the rising risk of overheating.

Why London Homes Overheat

It starts with the buildings themselves. Much of London’s housing stock was never built to retain heat efficiently — let alone manage excessive heat. Georgian and Victorian homes, for example, relied on open fireplaces, single glazing, and high ceilings to stay habitable. Heat loss was normal. Ventilation was natural. Thermal performance wasn’t the point.

Fast-forward to today, and we’ve sealed these homes up in the name of energy efficiency — draught-proofing, double glazing, better-insulated roofs and doors. These changes work well in winter. But in summer? The heat stays in, and the breeze stays out.

Add in other modern features like large glazed rear extensions, flat roofs with poor insulation, and heavy brick walls that soak up heat during the day and radiate it at night — and you’ve got the perfect conditions for overheating.

London’s Urban Heat Island: Why Some Areas Are Even Hotter

But this isn’t just about individual buildings. The city itself is changing the climate we live in.

London is one of the world’s most extreme urban heat islands. That means the dense built environment — all the asphalt, concrete, and dark rooftops — traps heat during the day and releases it slowly after sunset. Without trees or open spaces to provide shade or allow cooling, the temperature in some areas can remain stifling well into the night.

Take Kilburn, where we’ve worked on several projects. It’s a dense, built-up neighbourhood with limited green space and very few mature trees. During a summer heatwave, temperatures here can be up to 7ºC hotter at night than in nearby Regent’s Park — a leafy, open expanse that naturally regulates its microclimate through vegetation, water, and shade.

These localised temperature spikes aren’t just uncomfortable — they’re dangerous, especially for vulnerable residents in poorly ventilated top-floor flats or retrofitted homes without adequate shading.

Passive Cooling: Learning from the Past

The good news? We don’t need to rely on high-energy, high-cost cooling systems to solve the problem.

Passive design — smart strategies that work with climate and airflow — have been around for centuries. In cities like Barcelona, buildings were designed with deep balconies, external shutters, and high ceilings. These elements weren’t aesthetic flourishes — they were essential cooling tools.

At RISE, we draw inspiration from these techniques and apply them to the London context.

Some of the most effective passive cooling strategies include:
→ Adding brise soleils, pergolas or canopies above large glazed doors and windows
→ Installing external roller blinds or solar control film to block sun before it hits the glass
→ Using internal blinds with high-performance glazing to reduce solar gain
→ Creating cross ventilation — by opening windows on opposite sides of a room or floor
→ Designing stairwells with rooflights that act like chimneys to purge hot air

Passive doesn’t mean basic. It means enduring, resilient, and efficient.

How We Use Digital Twins to Design for Comfort

At RISE, we believe comfort shouldn’t be a guessing game. That’s why we create digital twins — detailed 3D models of real homes — to simulate how different strategies will perform before anything gets built.

With these models, we can:
→ Show how a tree or canopy will shade a room at the hottest time of day
→ Predict how solar control film will affect internal temperatures and glare
→ Test how hot air will escape through rooflights or stairwells
→ Visualise airflow through the building — spotting bottlenecks or breezes
→ Help clients make informed decisions that balance performance with budget

This approach means:
→ Fewer mistakes on site
→ No need to retrofit solutions after the fact
→ Greater comfort from day one

Technology Has a Role — But Design Should Lead

We’re not anti-tech. In fact, we often integrate smart systems into our designs. But the sequencing matters.

Here’s what we recommend:
→ Passive first — use design to minimise heat gain and promote natural ventilation
→ Smart systems second — air source heat pumps can gently cool in summer and heat in winter
→ Traditional AC only if essential — reserved for top-floor flats or homes with extreme glazing and limited ventilation potential

Why? Because conventional air conditioning uses a lot of electricity — and its external units release waste heat into the street. So while one home cools down, the neighbourhood gets hotter. Multiply that effect across thousands of homes, and we deepen the very crisis we’re trying to solve.

Designing for a Warmer World

Overheating isn’t a far-off problem. It’s here — now — and it’s getting worse with each summer.

But it’s also an opportunity. To rethink the way we design, renovate, and inhabit our homes. To stop relying solely on tech and start working with the environment, not against it.

At RISE, we’re helping people create homes that feel good in every season — and tread more lightly on the planet. That means better modelling, smarter materials, and design choices that prioritise both comfort and sustainability.

Because in this new climate, comfort can’t be a luxury.
It has to be designed in from the start.

Designing for a Warmer World

At RISE, we believe that designing for climate resilience isn’t just about cooling homes — it’s about rethinking comfort altogether. It’s about crafting spaces that respond to the rhythms of nature. That stay cool without compromise. That feel good to live in, even when the outside world doesn’t.

Concerned about overheating in your home — or planning a project that needs to be future-proof?
Let’s talk about how passive design, smart modelling, and sustainable choices can shape a home that stays comfortable for decades to come.

→ Email us at architects@risedesignstudio.co.uk
→ Or call the studio on 020 3947 5886

Earlier this week, I sat down with BBC London’s Alice Bhandhukravi for an interview about a growing issue that’s impacting homes across the capital — and shaping the way we design. While my contribution was a small part of the final broadcast, we spoke for nearly an hour about overheating in London’s homes, why it’s happening, and what we can do about it.

At RISE, we’ve been working with homeowners and developers to tackle this very issue — not just with technology, but with thoughtful, resilient design that makes homes genuinely comfortable to live in.

Why London Homes Overheat

It starts with the buildings themselves. Much of London’s housing stock was never built to retain heat efficiently — let alone manage excessive heat. Georgian and Victorian homes, for example, relied on open fireplaces, single glazing, and high ceilings to stay habitable. Heat loss was normal. Ventilation was natural. Thermal performance wasn’t the point.

Fast-forward to today, and we’ve sealed these homes up in the name of energy efficiency — draught-proofing, double glazing, better-insulated roofs and doors. These changes work well in winter. But in summer? The heat stays in, and the breeze stays out.

Add in other modern features like large glazed rear extensions, flat roofs with poor insulation, and heavy brick walls that soak up heat during the day and radiate it at night — and you’ve got the perfect conditions for overheating.

London’s Urban Heat Island: Why Some Areas Are Even Hotter

But this isn’t just about individual buildings. The city itself is changing the climate we live in.

London is one of the world’s most extreme urban heat islands. That means the dense built environment — all the asphalt, concrete, and dark rooftops — traps heat during the day and releases it slowly after sunset. Without trees or open spaces to provide shade or allow cooling, the temperature in some areas can remain stifling well into the night.

Take Kilburn, where we’ve worked on several projects. It’s a dense, built-up neighbourhood with limited green space and very few mature trees. During a summer heatwave, temperatures here can be up to 7ºC hotter at night than in nearby Regent’s Park — a leafy, open expanse that naturally regulates its microclimate through vegetation, water, and shade.

These localised temperature spikes aren’t just uncomfortable — they’re dangerous, especially for vulnerable residents in poorly ventilated top-floor flats or retrofitted homes without adequate shading.

Passive Cooling: Learning from the Past

The good news? We don’t need to rely on high-energy, high-cost cooling systems to solve the problem.

Passive design — smart strategies that work with climate and airflow — have been around for centuries. In cities like Barcelona, buildings were designed with deep balconies, external shutters, and high ceilings. These elements weren’t aesthetic flourishes — they were essential cooling tools.

At RISE, we draw inspiration from these techniques and apply them to the London context.

Some of the most effective passive cooling strategies include:
→ Adding brise soleils, pergolas or canopies above large glazed doors and windows
→ Installing external roller blinds or solar control film to block sun before it hits the glass
→ Using internal blinds with high-performance glazing to reduce solar gain
→ Creating cross ventilation — by opening windows on opposite sides of a room or floor
→ Designing stairwells with rooflights that act like chimneys to purge hot air

Passive doesn’t mean basic. It means enduring, resilient, and efficient.

How We Use Digital Twins to Design for Comfort

At RISE, we believe comfort shouldn’t be a guessing game. That’s why we create digital twins — detailed 3D models of real homes — to simulate how different strategies will perform before anything gets built.

With these models, we can:
→ Show how a tree or canopy will shade a room at the hottest time of day
→ Predict how solar control film will affect internal temperatures and glare
→ Test how hot air will escape through rooflights or stairwells
→ Visualise airflow through the building — spotting bottlenecks or breezes
→ Help clients make informed decisions that balance performance with budget

This approach means:
→ Fewer mistakes on site
→ No need to retrofit solutions after the fact
→ Greater comfort from day one

Technology Has a Role — But Design Should Lead

We’re not anti-tech. In fact, we often integrate smart systems into our designs. But the sequencing matters.

Here’s what we recommend:
→ Passive first — use design to minimise heat gain and promote natural ventilation
→ Smart systems second — air source heat pumps can gently cool in summer and heat in winter
→ Traditional AC only if essential — reserved for top-floor flats or homes with extreme glazing and limited ventilation potential

Why? Because conventional air conditioning uses a lot of electricity — and its external units release waste heat into the street. So while one home cools down, the neighbourhood gets hotter. Multiply that effect across thousands of homes, and we deepen the very crisis we’re trying to solve.

Designing for a Warmer World

Overheating isn’t a far-off problem. It’s here — now — and it’s getting worse with each summer.

But it’s also an opportunity. To rethink the way we design, renovate, and inhabit our homes. To stop relying solely on tech and start working with the environment, not against it.

At RISE, we’re helping people create homes that feel good in every season — and tread more lightly on the planet. That means better modelling, smarter materials, and design choices that prioritise both comfort and sustainability.

Because in this new climate, comfort can’t be a luxury.
It has to be designed in from the start.

Designing for a Warmer World

At RISE, we believe that designing for climate resilience isn’t just about cooling homes — it’s about rethinking comfort altogether. It’s about crafting spaces that respond to the rhythms of nature. That stay cool without compromise. That feel good to live in, even when the outside world doesn’t.

Concerned about overheating in your home — or planning a project that needs to be future-proof?
Let’s talk about how passive design, smart modelling, and sustainable choices can shape a home that stays comfortable for decades to come.

→ Email us at architects@risedesignstudio.co.uk
→ Or call the studio on 020 3947 5886

Earlier this week, I sat down with BBC London’s Alice Bhandhukravi for an interview about a growing issue that’s impacting homes across the capital — and shaping the way we design. While my contribution was a small part of the final broadcast, we spoke for nearly an hour about overheating in London’s homes, why it’s happening, and what we can do about it.

At RISE, we’ve been working with homeowners and developers to tackle this very issue — not just with technology, but with thoughtful, resilient design that makes homes genuinely comfortable to live in.

Why London Homes Overheat

It starts with the buildings themselves. Much of London’s housing stock was never built to retain heat efficiently — let alone manage excessive heat. Georgian and Victorian homes, for example, relied on open fireplaces, single glazing, and high ceilings to stay habitable. Heat loss was normal. Ventilation was natural. Thermal performance wasn’t the point.

Fast-forward to today, and we’ve sealed these homes up in the name of energy efficiency — draught-proofing, double glazing, better-insulated roofs and doors. These changes work well in winter. But in summer? The heat stays in, and the breeze stays out.

Add in other modern features like large glazed rear extensions, flat roofs with poor insulation, and heavy brick walls that soak up heat during the day and radiate it at night — and you’ve got the perfect conditions for overheating.

London’s Urban Heat Island: Why Some Areas Are Even Hotter

But this isn’t just about individual buildings. The city itself is changing the climate we live in.

London is one of the world’s most extreme urban heat islands. That means the dense built environment — all the asphalt, concrete, and dark rooftops — traps heat during the day and releases it slowly after sunset. Without trees or open spaces to provide shade or allow cooling, the temperature in some areas can remain stifling well into the night.

Take Kilburn, where we’ve worked on several projects. It’s a dense, built-up neighbourhood with limited green space and very few mature trees. During a summer heatwave, temperatures here can be up to 7ºC hotter at night than in nearby Regent’s Park — a leafy, open expanse that naturally regulates its microclimate through vegetation, water, and shade.

These localised temperature spikes aren’t just uncomfortable — they’re dangerous, especially for vulnerable residents in poorly ventilated top-floor flats or retrofitted homes without adequate shading.

Passive Cooling: Learning from the Past

The good news? We don’t need to rely on high-energy, high-cost cooling systems to solve the problem.

Passive design — smart strategies that work with climate and airflow — have been around for centuries. In cities like Barcelona, buildings were designed with deep balconies, external shutters, and high ceilings. These elements weren’t aesthetic flourishes — they were essential cooling tools.

At RISE, we draw inspiration from these techniques and apply them to the London context.

Some of the most effective passive cooling strategies include:
→ Adding brise soleils, pergolas or canopies above large glazed doors and windows
→ Installing external roller blinds or solar control film to block sun before it hits the glass
→ Using internal blinds with high-performance glazing to reduce solar gain
→ Creating cross ventilation — by opening windows on opposite sides of a room or floor
→ Designing stairwells with rooflights that act like chimneys to purge hot air

Passive doesn’t mean basic. It means enduring, resilient, and efficient.

How We Use Digital Twins to Design for Comfort

At RISE, we believe comfort shouldn’t be a guessing game. That’s why we create digital twins — detailed 3D models of real homes — to simulate how different strategies will perform before anything gets built.

With these models, we can:
→ Show how a tree or canopy will shade a room at the hottest time of day
→ Predict how solar control film will affect internal temperatures and glare
→ Test how hot air will escape through rooflights or stairwells
→ Visualise airflow through the building — spotting bottlenecks or breezes
→ Help clients make informed decisions that balance performance with budget

This approach means:
→ Fewer mistakes on site
→ No need to retrofit solutions after the fact
→ Greater comfort from day one

Technology Has a Role — But Design Should Lead

We’re not anti-tech. In fact, we often integrate smart systems into our designs. But the sequencing matters.

Here’s what we recommend:
→ Passive first — use design to minimise heat gain and promote natural ventilation
→ Smart systems second — air source heat pumps can gently cool in summer and heat in winter
→ Traditional AC only if essential — reserved for top-floor flats or homes with extreme glazing and limited ventilation potential

Why? Because conventional air conditioning uses a lot of electricity — and its external units release waste heat into the street. So while one home cools down, the neighbourhood gets hotter. Multiply that effect across thousands of homes, and we deepen the very crisis we’re trying to solve.

Designing for a Warmer World

Overheating isn’t a far-off problem. It’s here — now — and it’s getting worse with each summer.

But it’s also an opportunity. To rethink the way we design, renovate, and inhabit our homes. To stop relying solely on tech and start working with the environment, not against it.

At RISE, we’re helping people create homes that feel good in every season — and tread more lightly on the planet. That means better modelling, smarter materials, and design choices that prioritise both comfort and sustainability.

Because in this new climate, comfort can’t be a luxury.
It has to be designed in from the start.

Designing for a Warmer World

At RISE, we believe that designing for climate resilience isn’t just about cooling homes — it’s about rethinking comfort altogether. It’s about crafting spaces that respond to the rhythms of nature. That stay cool without compromise. That feel good to live in, even when the outside world doesn’t.

Concerned about overheating in your home — or planning a project that needs to be future-proof?
Let’s talk about how passive design, smart modelling, and sustainable choices can shape a home that stays comfortable for decades to come.

→ Email us at architects@risedesignstudio.co.uk
→ Or call the studio on 020 3947 5886

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