Greater London Authority, 2021
Sustainable infrastructure lies at the heart of the London Plan 2021, with Chapter 9 detailing the city's vision for tackling climate change, improving air quality, managing heat, and advancing a circular economy. These objectives deeply influence GJA’s approach to design and construction, guiding us toward resilient, efficient, and eco-conscious solutions. From adopting zero-carbon energy systems and minimising waste to innovating in water management and heat mitigation, we align every project with these priorities. This second blog in the London Plan series explores how GJA incorporates these goals into our work, driving London towards a more sustainable future.
Chapter 9 – SUSTAINABLE INFRASTRUCTURE
Improving Air Quality (Policy SI 1)
'Development Plans, through relevant strategic, site-specific and area-based policies, should seek opportunities to identify and deliver further improvements to air quality and should not reduce air quality benefits that result from the Mayor's or boroughs' activities to improve air quality.'
London’s struggle with air quality dates back to the early 19th century, when the infamous London Smog was caused by the widespread combustion of raw coal. Policies evolved over the years, leading to the banning of coal burning and, later, restrictions on wood fires, paving the way for gas-fired systems. Today, the city is undergoing a new transformation: the electrification of the energy system. This shift is part of a long-term strategy to decarbonise the energy network and phase out gas appliances for heating and cooking entirely, a priority for all boroughs under the London Plan.
Air quality improvement measures extend beyond energy systems to tackle other urban contributors to pollution, such as vehicular emissions. Policies like banning off-street parking in inner-city areas aim to reduce car usage and promote public transport, cycling, and walking. In boroughs like RBKC, new developments no longer eligible for residential parking spaces.
GJA’s Approach to Air Quality
At GJA, air quality considerations are central to both the design and construction phases of our projects.
Air Quality Assessments: Air quality assessments are a crucial component of development planning across London. While their specific formats may vary between boroughs, all assessments are guided by the overarching framework of the London Plan 2021.
Mechanical Ventilation with Filtration: GJA aims to integrate mechanical ventilation systems with advanced filters to trap pollen and carbon particles, ensuring superior indoor air quality for building occupants.
Sustainable Construction Practices: Construction and demolition activities can generate significant dust and particulate pollution. To mitigate this, GJA prioritises strategies like:
Factory-level preparation of materials, such as cutting wood or marble, to minimise onsite dust.
For example, at Rose Square, marble was pre-cut at the factory and installed directly on-site, preventing air quality issues during the construction process.
Exploring innovative uses for by-products like sawdust, which could potentially serve as future fuels, contributing to circular economy initiatives.
Designing for the Future: By addressing air quality at every stage of the project lifecycle, from initial design to post-completion operation, GJA ensures compliance with the London Plan while contributing to a healthier urban environment.
Minimising Greenhouse Gas Emissions (Policy SI 2) and Energy Infrastructure (Policy SI 3)
‘Major developments should be net zero-carbon. This means reducing greenhouse emissions in operation and minimising both annual and peak energy demand in accordance with the following energy hierarchy…be lean…be clean…be green…be seen.’
‘Development Plans should: 1) identify the need for, and suitable sites for, any necessary energy infrastructure requirements including energy centres, energy storage and upgrades to existing infrastructure. 2) identify existing heating and cooling networks, identify proposed locations for future heating and cooling networks and identify opportunities for expanding and inter-connecting existing networks as well as establishing new networks.’
The London Plan 2021 sets ambitious goals for reducing greenhouse gas emissions and modernising energy infrastructure. At its core, the policies aim to drive London towards becoming a net-zero carbon city, reshaping how energy is produced, stored, and consumed. At GJA, we are not only committed to meeting these standards but also actively exploring innovative solutions that go beyond compliance.
GJA has embraced this challenge in several projects, blending cutting-edge technologies with a practical approach to energy efficiency:
Hydrogen Boilers and Micronuclear Pods: At York Terrace East, a client with deep roots in traditional energy sectors is exploring revolutionary technologies such as hydrogen boilers and micronuclear pods. These pods, still in development, promise decentralised energy production, reducing the need for extensive cabling and step-down transformers. If deployed nationally, they could transform energy efficiency on a local scale.
Electrification and Decarbonisation: The shift from gas boilers to electric systems marks a significant step in decarbonising London’s energy. However, challenges persist, especially for listed buildings where solar panels and other renewable installations are restricted. At GJA, we work around these limitations, enhancing thermal performance and airtightness to achieve energy efficiency.
Overcoming Barriers in Energy Efficiency
Historic Buildings and Insulation: Much of the UK’s housing stock, especially older buildings, suffers from poor insulation. At York Terrace West, for instance, we’ve tackled the challenges of a Grade I listed property. With its large windows and historical design constraints, GJA aims to install energy efficiency measures such a double glazing and airtight seals to reduce energy demand drastically - from 15KW to just 5KW during cold spells.
Economic Incentives: While regulations push for energy efficiency, they often lack sufficient financial incentives. Property owners face significant upfront costs to upgrade insulation or improve energy performance, without corresponding increases in rental value. To achieve widespread change, enhanced subsidies and incentives for energy efficiency are critical.
Smart Solutions for Heating and Cooling
Policy SI 3 calls for innovative energy infrastructure, including interconnected heating and cooling networks. At GJA, we’ve adopted strategies like the ambient loop, a system that redistributes heat and energy within buildings, reducing waste and maximizing efficiency. This is particularly important in larger developments, where energy recovery can substantially lower operational costs and emissions.
Managing Heat Risks (Policy SI 4)
‘Development proposals should minimise adverse impacts on the urban heat island through design, layout, orientation, materials and the incorporations of green infrastructure’
As global temperatures rise, urban areas like London face increased challenges in managing heat. GJA embraces this challenge, integrating innovative solutions to mitigate heat risks while ensuring comfort and sustainability for building occupants.
Understanding Heat Risk
“We are getting warmer,” notes GJA’s founder, reflecting on the realities of climate change and urban heat gain. As cities become more dense, the urban heat island (UHI) effect intensifies, with surfaces like roads, buildings, and pavements absorbing and trapping heat. This phenomenon causes city centres to experience significantly higher temperatures (up to 10°C) compared to rural areas. Tackling these rising temperatures requires innovative design strategies and cutting-edge technologies to effectively manage heat risks and create more sustainable urban environments.
Designing for Heat Mitigation
In response to rising temperatures, GJA employs a combination of strategies to manage heat gain and improve building performance:
Passive Cooling Systems: GJA prioritises passive cooling to reduce reliance on energy-intensive systems like air conditioning. Passive thermal management is a cost-effective and energy-efficient solution that relies on heat sinks, heat spreaders, heat pipes or thermal interface materials (TIM) to maintain optimal operating temperatures.
Geothermal Technology: One of the most efficient solutions GJA utilises is geothermal cooling. By installing pipes deep in the ground, where temperatures remain a steady 10°C, we can cool building materials passively. For example, geothermal pipes connected to an underfloor manifold can reduce floor temperatures to 16°C, providing a consistent cooling effect. This system, combined with underfloor heating and passive ceiling cooling, offers year-round thermal regulation.
Heat Pumps: Heat pumps are another critical component of GJA’s strategy. Not only are they efficient - producing 3-4kW of cooling energy for every 1kW of input—they can be reversed to provide heating in colder months. Geothermal systems are even more efficient, delivering 6-8kW of output for every 1kW of input energy.
Water Infrastructure (Policy SI 5)
‘In order to minimise the use of mains water, water supplies and resources should be protected and conserved in a sustainable manner. Development Plans should promote improvements to water supply infrastructure to contribute to security of supply. This should be done in a timely, efficient and sustainable manner taking energy consumption into account.’
At GJA, we understand the critical role that water infrastructure plays in shaping sustainable urban environments. From reducing consumption to innovative recycling systems, our projects reflect a commitment to addressing this vital issue.
The UK’s Challenge with Grey Water Systems
Grey water - recycled water from sources such as showers and baths—is widely used across Europe for non-potable purposes like flushing toilets. However, as GJA’s founder points out, the UK’s infrastructure has lagged behind in adopting these systems. This has created a challenge for architects and developers: how do we reduce water consumption while working within existing infrastructure constraints?
Innovative Water-Saving Measures at GJA
GJA incorporates practical and forward-thinking solutions to reduce water consumption and promote sustainability in its projects:
Dual-Flush Toilets: A simple yet impactful innovation, dual-flush toilets allow users to choose between a full or partial flush, significantly reducing water usage. At GJA, installing these systems is a standard practice, as consumption is key to sustainable water management.
Rainwater Harvesting and Grey Water Systems: At York Terrace East, GJA is pioneering the use of grey water recycling. Rainwater is collected, filtered, and treated with ultraviolet (UV) light to make it safe for reuse in non-potable applications such as flushing toilets or irrigation. Additionally, wastewater from showers and baths is diverted through separate drains, facilitating its recycling and reuse.
Smart Water Infrastructure Design: GJA’s approach to water infrastructure extends beyond individual features to systemic planning. By designing separate drainage systems for kitchen and toilet waste versus shower and bath waste, GJA ensures that wastewater can be effectively treated and reused. This reduces reliance on mains water while conserving resources.
Reducing waste and supporting the circular economy (Policy SI 7)
Source: Building Revolutions (2016), David Cheshire, RIBA Publishing
‘Resource conservation, waste reduction, increases in material re-use and recycling, and reductions in waste going for disposal will be achieved…Referable applications should promote circular economy outcomes and aim to be net zero-waste.’
Waste Management: Beyond the Skips
The construction industry has long grappled with waste, often visualised by rows of skips overflowing with discarded materials. GJA is rethinking this approach, shifting from traditional construction practices to innovative methods that minimize waste at every stage.
Key strategies include:
Prefabrication at Factories: By fabricating materials off-site, we ensure only what’s needed is used. This approach reduces waste, cuts transportation emissions, and improves precision.
Minimising Packaging: Materials are delivered with minimal protection to reduce unnecessary waste on-site. For example, at Rose Square, materials arrived pre-finished, drastically reducing the need for on-site adjustments and waste generation.
Streamlining On-Site Operations: We invest time at factories during pre-construction phases to ensure operations at the site are as efficient and waste-free as possible.
Circular Economy in Action
GJA actively incorporates circular economy principles, turning potential waste into resources:
Pre-construction Audits: Before starting a project, we assess what materials can be reused or recycled. For instance, bricks and marble from demolitions are repurposed into aggregates or other building elements.
On-Site Recycling: At Hanover Lodge, marble was crushed on-site and bagged for use as aggregate, while wood was separated for reuse, achieving a 95% material recovery rate — exceeding standard requirements.
Innovative Material Use: We integrate materials like repurposed wood and crushed brick into new construction, reducing dependency on virgin resources and lowering embedded carbon.
Addressing Systemic Challenges
Despite advancements in project-level waste management, broader systemic issues remain. London's recycling infrastructure is disjointed, making it challenging to fully embrace a cohesive circular economy. While planning applications require provisions for recycling storage, developers often face resistance due to space constraints and conflicting financial priorities.
Construction accounted for 62% of all waste in 2023, underscoring the urgent need for change. GJA believes that while policy mandates like the London Plan 2021 lay the groundwork,“there’s not enough joined-up thinking going on”, therefore achieving meaningful progress requires collaboration between planners, developers, and policymakers.
A Vision for Sustainable Construction
At GJA, we don’t just meet the requirements; we exceed them. Whether it’s through reducing waste on-site, reimagining how materials are sourced and used, or repurposing demolished elements, we are committed to creating a sustainable future in construction.
The circular economy is not just a goal - it’s a necessity. By embedding its principles into every project, GJA demonstrates how the built environment can evolve to support both people and the planet.
Aggregates (Policy SI 10)
‘An adequate supply of aggregates to support construction in London will be achieved by: 1) encouraging re-use and recycling of construction, demolition and excavation waste within London, including on-site. 2) extracting land-won aggregates within London. 3) importing aggregates to London by sustainable transport modes.’
The Role of Aggregates in Sustainable Construction
Aggregates, the building blocks of concrete and construction, hold significant potential for sustainability. One of the most efficient ways to reduce carbon emissions in construction is by reusing aggregates. Marine-dredged aggregates, for example, can be bound and repurposed, while materials like crushed concrete and bricks can enter the circular economy instead of heading to landfills.
As the founder of GJA notes, "Reusing aggregates is becoming a huge thing, and rightly so." However, this effort requires better coordination across the industry, particularly in a complex city like London where space and logistics can pose challenges.
On-Site Crushing and Repurposing: GJA’s Proven Strategy
At GJA, we’ve been championing the reuse of aggregates for years. For example:
Wentworth Project: 15 years ago, we demolished a building and brought a brick crusher on-site. By crushing and reusing all the bricks, we saved substantial embedded carbon, minimised vehicle movements, and repurposed the materials directly on-site.
Passmore Street: At this current project, materials were carefully bagged and sent to specific repurposing facilities, such as wood pulp plants, ensuring nothing went to waste.
This localised approach to crushing and repurposing not only reduces environmental impact but also supports the London Plan’s goals of reducing dependency on new materials and minimising waste.
A Vision for Aggregates in London
The use of recycled and repurposed aggregates is a key component of sustainable construction, and Policy SI 10 of the London Plan provides a strong framework for achieving these goals. At GJA, we are committed to pushing the boundaries of what’s possible, from reducing embedded carbon to integrating circular economy principles into every project.
Sustainable drainage (Policy SI 13)
‘Drainage should be designed and implemented in ways that promote multiple benefits including increased water use efficiency, improved water quality, and enhanced biodiversity, urban greening, amenity and recreation.’
At GJA, we integrate the principles of sustainable drainage into every stage of our projects, ensuring that our developments not only meet regulatory requirements but also contribute to a more sustainable, resilient urban landscape.
What Are Sustainable Drainage Systems (SuDS)?
SuDS mimic natural water management processes, controlling rainfall as close to its source as possible. They achieve this by:
Slowing Runoff: Attenuating water to reduce the speed at which it enters sewers or watercourses.
Storing Water: Using natural or man-made features to store water temporarily in natural contours or specialized tanks.
Promoting Biodiversity: Incorporating green and blue features such as green roofs or attenuation tanks that irrigate plant life.
Improving Water Quality: Reducing pollution in local water bodies through natural filtration and separation processes.
SuDS not only mitigate flooding risks but also enhance the urban environment by integrating natural features, improving aesthetics, and supporting ecosystems.
GJA’s Approach to SuDS
Sustainable drainage systems are a key element of GJA’s approach to modern development:
Rainwater Recovery and Reuse: At York Terrace East, GJA focuses on repurposing water for shared spaces such as common areas. Greywater systems separate waste streams enabling efficient water recovery and reuse while adapting to the infrastructure limitations in private apartments.
Groundwater Attenuation Systems: At Egerton Crescent, GJA employs underground tanks to manage rainwater flow. These tanks temporarily store excess rainwater, releasing it gradually into sewer systems. This approach decreases the rate of water entering the sewer, helping to prevent flooding and reduce strain on London’s combined sewer system.
Pre-installed Rainwater Harvesting for Irrigation: At Hanover Lodge, pre-installed underground tanks were designed to collect and store rainwater, offering a sustainable solution for irrigation purposes.
Challenges and Opportunities
London’s current infrastructure presents challenges for implementing widespread greywater systems. As the founder of GJA explains:
“Greywater systems require aligned infrastructure to be truly effective. Until that evolves, we focus on SuDS and rainwater recovery to meet sustainability goals.”
The city’s combined sewer system, which handles both sewage and rainwater, underscores the need for innovative drainage solutions.
As we’ve explored, the London Plan 2021 sets a clear path for a sustainable future, influencing how we at GJA approach air quality, energy efficiency, heat mitigation, water management, and waste reduction. By embedding innovative solutions and circular economy principles into our projects, we not only are guided by these ambitious goals but aim to exceed them.
In the next blog, Navigating Contradictions – Balancing Priorities, we’ll delve into the complexities of aligning overlapping and sometimes conflicting policies, sharing how GJA strikes a balance to deliver sustainable, forward-thinking designs.
Comments