Located in the heart of Birkenhead Park, the world’s first municipal park, Central Lodge is a Grade II Listed building undergoing a full retrofit to achieve the rigorous Passivhaus EnerPHit standard. This landmark project may become the first EnerPHit certified listed building in the world.
Designed and executed by Lancashire Heritage, the retrofit combines traditional conservation craftsmanship with advanced building performance methods. The project is also supported by ongoing research from the University of Liverpool, contributing valuable insight into the sustainable preservation of historic architecture.
Challenges
Retrofitting a listed structure to meet EnerPHit standards presented a series of complex challenges:
Preserving the building’s architectural character while delivering modern comfort and efficiency
Maintaining the historic fabric of the building while integrating airtightness and insulation layers
Achieving reliable thermal performance and moisture control within solid walls that were never designed for airtightness
Managing the junctions between old and new construction, particularly where the contemporary concrete extension meets the original sandstone and wood fibre insulated walls
Preserving the building’s architectural character while delivering modern comfort and efficiency
Images courtesy of Progress in Practice
Solution
The project required a hybrid approach, merging traditional materials with high performance building products from Partel to deliver both durability and breathability.
Specified Products:
- VARA PLUS intelligent vapour control membrane
- IZOPERM PLUS vapour control layer (VCL) for ceiling applications
- CONEXO MULTI SEAL airtight tape for junctions and penetrations
These systems were installed to create a continuous airtight layer across the structure, while maintaining the building’s ability to manage moisture naturally. The vapour control layer applied to the ceilings provided essential protection against interstitial condensation, particularly in the transition zones between the existing timber structure and the new concrete extension.
The walls were internally insulated with wood fibre boards finished with lime plaster, ensuring the assembly remained breathable and sympathetic to the original construction. A striking contrast is created between the restored lodge and its new concrete basement extension, which is partially underground and finished with contemporary sandstone cladding. This design demonstrates a careful balance between heritage conservation and modern intervention. Concrete meets wood fibre and stone, forming a dialogue between eras while maintaining structural integrity and performance.
Results
Although completion is expected in Spring 2026, preliminary testing has shown exceptional airtightness values. The performance of Partel membranes and tapes has given the project team confidence to target full EnerPHit certification.
Residents will benefit from improved indoor air quality, stable thermal comfort, and reduced operational energy consumption, all while retaining the original charm and heritage of the property.
Central Lodge represents a pioneering approach to heritage retrofit. It proves that historic preservation and modern energy performance can coexist successfully.
By combining breathable natural materials with precision engineered membranes and sealing systems, Partel’s VARA PLUS, IZOPERM PLUS, and CONEXO MULTI SEAL have demonstrated how modern products can merge seamlessly with traditional methods.
This project shows that with the right technical solutions, even a Grade II Listed building can be future ready and sustainable for generations to come.
Project DetailsLocation: Birkenhead Park, United Kingdom
Standard: Targeting Passivhaus EnerPHit certification
Contractor: Lancashire Heritage
Windows: Existing retrofitted with vacuum glazing by Crystal Clear Glazing; new Viking windows by Retrofit Windows
Ventilation: Zehnder ComfoAir Q350 MVHR with semi rigid ductwork by 21 Degrees
Heating & Hot Water: Air Source Heat Pump
Solar: 13 monocrystalline modules with battery storage
Photography: Progress in Practice
Completion: Spring 2026
