Energy Efficiency Retrofitting in London
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Old buildings shouldn’t mean old performance.
At Bigness Group, we specialise in energy efficiency retrofitting — upgrading London properties to meet modern environmental standards without losing character or comfort.
Whether it’s insulation, renewable energy systems, smart controls, or full PAS 2035 compliance, we make existing buildings cleaner, greener, and cheaper to run.
Our retrofitting experts combine design insight, technical precision, and sustainable materials to turn energy-wasting properties into efficient, future-ready assets.
What Is Energy Efficiency Retrofitting?
Retrofitting means improving the energy performance of an existing building through modern technologies and building-fabric upgrades.
It’s not just about insulation — it’s a complete approach that integrates heating, ventilation, lighting, and control systems.
By applying tailored measures, Bigness Group helps reduce energy consumption, improve indoor comfort, and increase a property’s EPC rating, all while meeting local council and UK net-zero targets.
Our Retrofitting Services
We deliver end-to-end retrofit solutions for homeowners, landlords, housing associations, and commercial developers.
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Fabric Upgrades & Insulation – Wall, roof, and floor insulation to reduce heat loss and drafts.
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High-Performance Windows & Doors – Double and triple glazing installations for optimal thermal efficiency.
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Air-Tightness & Ventilation – Balanced systems such as MVHR to maintain healthy air quality while minimising heat loss.
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Heating System Optimisation – Boiler upgrades, smart thermostats, and integration of air-source or ground-source heat pumps.
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Renewable Energy Integration – Solar PV, battery storage, and hybrid heating to lower carbon output.
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Lighting & Power Efficiency – LED conversion, occupancy sensors, and energy-saving electrical systems.
Each retrofit package is fully designed, modelled, and documented in line with PAS 2035 standards.
Our Process
We take a structured, evidence-based approach so every retrofit delivers measurable results.
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Assessment & Energy Audit – Using digital modelling and on-site testing to identify inefficiencies and prioritise actions.
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Design & Specification – Our engineers develop detailed improvement plans with cost-benefit projections.
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Implementation & Installation – Certified teams carry out works with minimal disruption and complete safety compliance.
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Testing & Verification – Post-works testing confirms real-world energy savings and performance improvements.
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Monitoring & Aftercare – Long-term support ensures systems continue to deliver the expected savings.
This process gives clients full transparency — you see what’s being done, why it matters, and how much you’ll save.
Why Choose Bigness Group
Bigness Group brings decades of multi-trade experience together with a sustainability mindset.
We operate under a clear governance framework focused on ethical delivery, environmental responsibility, and measurable performance.
Our clients trust us to deliver real efficiency gains — not just green marketing claims.
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PAS 2035-aligned methodology and certified retrofit coordinators
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Transparent reporting and cost tracking
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Partnerships with leading energy-tech suppliers
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Proven experience across housing, offices, and mixed-use developments
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Commitment to UK Net-Zero 2050 goals
With Bigness, sustainability isn’t a buzzword — it’s the foundation of everything we build.
Frequently Asked Questions
Q: What’s included in a typical retrofit?
Insulation, ventilation, heating optimisation, glazing, and renewable energy systems — all tailored to the property.
Q: Can you retrofit while the building is occupied?
Yes. We phase works carefully to minimise disruption for residents or tenants.
Q: Do you help with funding or grants?
We can guide you through government or local-authority energy-efficiency schemes and provide supporting documentation.
Q: What’s the difference between renovation and retrofit?
Renovation improves appearance; retrofit improves performance — we often combine both for the best results.
Q: How much energy can I save?
Depending on property type, savings can range from 20 % to 60 % in annual energy costs.
Recent Retrofit Projects
See how Bigness Group has helped clients cut emissions, boost EPC ratings, and future-proof their properties.
Each project demonstrates our ability to combine design quality, technical skill, and environmental impact — proving that efficiency and elegance can coexist.
Energy Efficiency Retrofitting Across London
We deliver retrofit projects throughout Greater London — from period homes in Kensington to modern blocks in Croydon. Our teams understand each borough’s planning policies, heritage considerations, and sustainability targets, ensuring compliance and smooth delivery. No matter the scale, we bring precision engineering, verified materials, and full documentation to every site.
Barking and Dagenham / Barnet / Bexley / Brent / Bromley / Camden / Croydon / Ealing / Enfield / Greenwich / Hackney / Hammersmith and Fulham / Haringey / Harrow / Havering / Hillingdon / Hounslow / Islington / Kensington and Chelsea / Kingston upon Thames / Lambeth / Lewisham / Merton / Newham / Redbridge / Richmond upon Thames / Southwark / Sutton / Tower Hamlets / Waltham Forest / Wandsworth / Westminster