A Passive Haus Timber Frame Extension

On the outskirts of Norwich, our team worked on a Passive Haus project: expanding a Passive House with a timber frame extension.

A Holistic Approach

The existing Passive Haus, already a paragon of energy efficiency, presented a unique challenge. We needed to seamlessly integrate an addition that would not only match but maintain the rigorous Passive Haus standards, which demand ultra-low energy consumption and superior thermal comfort. Our client wanted a 8m x 6m living space that would serve dual purposes as both a dining room and a cozy snug, all while offering picturesque views of their back garden.

This project required meticulous planning and execution to ensure that the new extension would harmonise with the existing Passive Haus both aesthetically and functionally. We chose a timber frame construction for its excellent thermal properties, sustainability, and ability to achieve the airtight building envelope crucial to Passive Haus standards. The design incorporated triple-glazed windows to maximise natural light and views while maintaining superb insulation. Every joint, connection, and material transition was carefully considered to prevent thermal bridges and maintain the home’s exceptional energy performance. The result was a beautiful, light-filled space that seamlessly blended with the original structure, expanding the family’s living area.

Project Overview

Challenge

Expand the living space of a Passive Haus without compromising its strict energy efficiency standards
Design and construct an 8m x 6m extension that seamlessly integrates with the existing structure
Maintain the rigorous air tightness and ventilation requirements of Passive Haus certification
Ensure the new space enhances the homeowners’ lifestyle while preserving the home’s environmental performance

Solution

Using our expertise in both Passive Haus principles and timber frame construction, we implemented:

A carefully designed timber frame extension using structurally insulated panels (SIPs)
Meticulous attention to air tightness detailing at all junctions between new and existing structures
Integration of the extension’s ventilation system with the existing Passive Haus mechanical ventilation with heat recovery (MVHR) system
Selection of high-performance windows and doors to maintain thermal efficiency
Use of eco-friendly, sustainable materials throughout the construction process

Process Highlight

Our design and construction teams collaborated to:

Conduct a thorough assessment of the existing Passive Haus to ensure seamless integration
Create detailed 3D models to optimise the extension’s thermal performance
Carefully select and install materials that meet or exceed Passive Haus standards
Implement rigorous quality control measures to ensure air tightness targets were met
Coordinate with Passive Haus certifiers throughout the project to maintain certification

Results

Successfully expanded the living space by 48 square meters while maintaining Passive Haus certification
Achieved an air tightness level of 0.5 air changes per hour at 50 Pascals pressure (ACH50), meeting the strict Passive Haus standard
Integrated the new space seamlessly with the existing structure, both aesthetically and functionally
Provided the homeowners with a light-filled, energy-efficient space that enhances their quality of life
Demonstrated the possibility of expanding Passive Haus buildings without compromising their performance

Customer Feedback

”We were thrilled with the result of our extension. The team's expertise in both Passive Haus principles and timber frame construction was evident throughout the process. We now have a beautiful, spacious area to enjoy our garden views, and we're amazed that it maintains the same incredible energy efficiency as the rest of our home." - Michael S
Michael SHomeowner

Conclusion

This project showcases our ability to expand Passive Haus buildings while strictly adhering to their principles.

By combining our knowledge of timber frame construction with Passive Haus standards, we delivered an extension that not only meets the homeowners’ needs for additional space but also maintains the home’s exceptional energy performance.

Are you a home owner looking to expand your living space without compromising on energy efficiency?

Contact Red Wolfe