EnerPhit: transforming existing homes into high-performance buildings

Retrofitting an existing building to high energy-efficiency standards is one of the most impactful ways to reduce energy consumption, lower carbon emissions, and improve comfort. At Gresford Architects, we specialise in EnerPhit-certified retrofits — an advanced standard developed by the PassivHaus Institute for upgrading existing buildings to near PassivHaus levels of performance.

An EnerPhit retrofit significantly improves airtightness, insulation, ventilation, and energy efficiency while respecting the integrity of the original structure. Whether you’re looking to enhance the sustainability of a period property or modernise a post-war home, we bring the expertise needed to achieve remarkable energy reductions without compromising character or aesthetics.

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What is EnerPhit?

EnerPhit is the gold standard for retrofitting existing buildings, offering many of the benefits of a full PassivHaus build but adapted to the constraints of an existing structure. It ensures:

Up to 90% energy savings compared to conventional buildings.

Significantly improved indoor air quality with a stable, comfortable temperature year-round.

Reduced reliance on heating and cooling systems, lowering running costs.

Enhanced durability through the use of high-performance materials and detailing.

Because many existing buildings cannot achieve full PassivHaus certification due to structural limitations, EnerPhit provides a practical and highly effective approach to achieving low-energy, sustainable living.

[Learn More About EnerPhit Standards →]

Our approach to EnerPhit Retrofits

At Gresford Architects, we take a meticulous, whole-building approach to EnerPhit retrofits, ensuring each project achieves the highest possible performance while respecting the building’s original character and materials.

1. High-Performance Insulation & Airtightness

Carefully upgrading walls, roofs, and floors with advanced insulation techniques to significantly reduce heat loss while maintaining breathability.

2. Advanced Ventilation & Indoor Air Quality

Installing Mechanical Ventilation with Heat Recovery (MVHR) systems to provide continuous fresh, filtered air while retaining warmth.

3. Thermal Bridge-Free Detailing

Minimising weak points in insulation that lead to heat loss, ensuring a uniform, comfortable indoor temperature.

4. High-Efficiency Windows & Doors

Upgrading to triple-glazed, airtight units that enhance energy retention while maximising daylight.

5. Sustainable Heating & Renewable Energy

Integrating air-source or ground-source heat pumps, solar PV, and energy storage to reduce reliance on fossil fuels.

[Discover How We Optimise Homes for EnerPhit Performance →]

EnerPhit Retrofits in action: case studies

Please note that the following case studies are placeholders and will be updated with detailed project information upon client approval.

Project 1 – TO BE REPLACED

A Victorian townhouse retrofitted to EnerPhit standards, reducing energy consumption by 80% while preserving its historic façade.

Project 2 – TO BE REPLACED

A 1950s detached home upgraded with super-insulated external cladding, MVHR, and solar energy solutions.

Project 3 – TO BE REPLACED

An EnerPhit renovation of a former industrial space into a contemporary, ultra-low-energy dwelling.

[View Our Projects →]

Why choose Gresford Architects for your EnerPhit Retrofit?

Certified EnerPhit & PassivHaus expertise

We are specialists in low-energy retrofits and members of the PassivHaus Trust, ensuring the highest standards of energy performance.

Sustainability & performance-driven design

We take a whole-building approach to sustainability, ensuring every intervention enhances both efficiency and comfort.

Bespoke retrofit strategies

Every home is different—we develop tailored solutions that balance energy performance with aesthetics and heritage considerations.

Seamless project delivery

From initial feasibility studies to construction oversight, we manage the entire process, ensuring precision and quality at every stage.

Ready to future-proof your home?

If you’re looking to upgrade your home with an EnerPhit retrofit, we’d love to discuss how we can help you achieve outstanding energy performance and comfort.

Book a consultation: Contact Us

Speak to our team: Call us at +44 (0)1865 360 037

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