When it comes to sustainable building standards, EnerPhit and Passivhaus are two prominent terms often heard in the realm of eco-friendly construction. Though they share similarities, fundamentally, these standards are distinct in their objectives and application. This blog explores the nuances between EnerPhit and Passivhaus.

Understanding Passivhaus

Passivhaus, also known as Passive House, is a rigorous, voluntary standard for energy efficiency in a building. It dramatically reduces the building’s ecological footprint. Originating in Germany in the early 1990s, this standard aims to create structures that are ultra-low in energy consumption while providing high levels of comfort and health for occupants. Key characteristics of a Passivhaus include:

• Superior Insulation: Highly insulated walls, roof, and floors to minimise heat loss.
• Airtight Construction: Virtually eliminates draughts and ensures a consistent indoor environment.
• Mechanical Ventilation Heat Recovery (MVHR): Maintains air quality while recovering heat from the air leaving the building.
• High-Performance Windows: Typically triple-glazed to enhance insulation and reduce heat loss.
• Thermal Bridge-Free Construction: This avoids cold spots and ensures even temperature distribution.

EnerPhit: The Retrofit Counterpart

EnerPhit represents a significant stride in the field of sustainable retrofitting. As the retrofit equivalent of the Passivhaus standard, it’s specifically tailored to upgrade existing buildings, a task often laden with unique challenges and constraints. Let’s delve deeper into what makes EnerPhit a pivotal standard in the world of eco-friendly refurbishments.

Tailored approach for existing structures

• Assessment of the Original Building: EnerPhit involves a detailed analysis of the existing structure, considering its age, construction materials, historical value, and current energy performance.
• Customised Energy Solutions: Each retrofit project under EnerPhit is unique. Solutions are customised to the building’s specific needs, balancing energy efficiency with architectural preservation.

Key retrofitting measures in EnerPhit

• Enhanced Insulation: Adding or improving insulation in walls, roofs, and floors to reduce heat loss, while being mindful of the building’s existing architecture.
• Upgrading Windows and Doors: Replacing or upgrading to high-performance windows and doors to improve thermal performance without compromising the building’s character.
• Addressing Thermal Bridges: Identifying and mitigating thermal bridges to prevent heat loss and condensation issues.
• Improving Airtightness: Sealing gaps and leaks to create a more airtight building envelope, which is crucial for maintaining a stable indoor climate.
• Ventilation Systems: Incorporating efficient ventilation systems, often with heat recovery features, to ensure good indoor air quality without significant heat loss.

Challenges and considerations in EnerPhit retrofitting

• Structural Limitations: Older buildings may have structural limitations that restrict the extent of retrofitting possible.
• Preservation of Character: In historic buildings, preserving architectural integrity is crucial, sometimes limiting the scope of energy-efficient upgrades.
• Cost Implications: Retrofitting to EnerPhit standards can be more expensive than standard refurbishments. Specialised materials and techniques are often required.
• Planning and Permissions: Retrofit projects, especially in historic buildings, may require navigating complex planning permissions and regulations.

Benefits of EnerPhit certification

• Energy Efficiency: Significant reduction in energy consumption, leading to lower utility bills and reduced carbon footprint.
• Enhanced Comfort: Improved thermal comfort with stable indoor temperatures and reduced drafts.
• Increased Property Value: EnerPhit-certified buildings often see an increase in market value due to their enhanced energy performance and comfort levels.
• Sustainable Living: Contributing to environmental sustainability by reducing the building’s ecological impact.

Key Differences Between EnerPhit and Passivhaus

Passivhaus is specifically designed for new constructions, with a focus on achieving maximum energy efficiency from the ground up. This approach allows for the integration of energy-efficient features into the building’s design right from the start, ensuring an optimal performance in terms of energy conservation and sustainability.

In contrast, EnerPhit is tailored for existing buildings. It aims to upgrade these structures to standards that closely align with those of Passivhaus. This involves adapting and retrofitting older buildings, a task that often comes with its own set of challenges. EnerPhit recognises these unique difficulties and provides a more achievable pathway for bringing existing buildings up to par with modern energy efficiency standards.

This leads us to the aspect of certification criteria. EnerPhit’s requirements are slightly less stringent compared to Passivhaus. This relaxation in standards is a practical acknowledgement of the constraints and complications often encountered during retrofit projects. Older buildings may have structural limitations or historical features that need preservation. This makes it impractical to meet the exacting standards of Passivhaus.

Furthermore, EnerPhit offers greater flexibility in meeting its criteria, understanding that each retrofit project is unique. This flexibility is crucial as it allows for custom solutions that respect the original structure’s integrity while still significantly improving its energy performance.

Finally, the cost and complexity of retrofitting an existing building to meet EnerPhit standards can be higher on a per square metre basis than building a new Passivhaus. This is largely due to the intricacies involved in working with pre-existing structures. Each building presents its own set of challenges. This ranges from integrating modern insulation into walls not designed for them, to upgrading windows and ventilation systems in a way that respects the building’s original architecture.