Project Overview

The Ferndale Rise Retrofit project demonstrates how a traditional 1930s semi-detached property can be transformed into a high-performance, energy-efficient home through modern retrofit techniques.

Working alongside Koru Construction and The Cambridge Building Society, Intelligent Membranes supplied airtightness and masonry protection solutions to help deliver exceptional building performance.

The Challenge

The objective was to take an ageing property and dramatically improve its thermal performance, airtightness and long-term durability while retaining the character of the original building.

The property was stripped back to brick, allowing the project team to rebuild using modern construction techniques and high-performance materials.

Airtightness Solution: Passive Purple

Airtightness was a critical requirement of the project.

Passive Purple was selected due to its ability to create a seamless airtight layer across the internal building envelope.

Benefits Delivered

• Passivhaus Component A Certified
• Independently tested to 0.034 ACH
• Radon barrier protection
• Fire Class C performance
• Seamless application with no joints or overlaps
• Flexible crack-bridging technology

The Intelligent Membranes team first applied Passive Purple Brush to junctions, service penetrations, cracks and gaps before spray-applying Passive Purple across the building envelope.

External Protection: Brick Seal

To further improve building performance and durability, Brick Seal was applied to the external masonry following restoration and repointing works.

Brick Seal penetrates deep into masonry before curing to form an invisible water-repellent barrier.

Benefits Delivered

• Reduced moisture absorption
• Improved thermal performance
• Protection against freeze-thaw damage
• Reduced staining and efflorescence
• Long-term façade protection

Results

The completed project achieved an impressive airtightness result of:

0.54 ACH

This result demonstrates the effectiveness of combining quality workmanship, detailed retrofit planning and proven airtightness technology.

Conclusion

The Ferndale Rise Retrofit showcases what can be achieved when experienced retrofit specialists and innovative building products work together.

Through the use of Passive Purple and Brick Seal, the property now benefits from improved energy efficiency, reduced air leakage, enhanced occupant comfort and long-term protection of the building fabric.

Planning a retrofit? Get in touch today.