Woodfibre insulation from Soprema’s Pavatex range has been used to transform the thermal performance of a listed Georgian house in Oxfordshire and ensure a new extension, delivered as part of the same renovation, is in keeping with the fabric of the original building.
Energy Efficiency in Heritage Property
Manor Farm is home to Natasha Ginks and her family and, after completing an MSc in Climate Change and sustainability, Natasha has been passionate about improving the energy efficiency of her family home, without compromising the character or building physics of the heritage property.
Pavatax: a Natural Choice
Natasha’s understanding of retrofit best practice first led her to use Pavatex woodfibre insulation and airtightness membranes when the roof of the building was refurbished two years ago. Consequently, when she began to plan renovations for the property and a new extension, Pavatex was a natural choice.
“We worked with Alex Towler at Transition by Design to design the refurbishment of the main house, the new extension and improvements to a former barn on the property, which we use as a guest room and a games room.”
“From the outset, increased thermal efficiency and an airtight building envelope were central goals of the project and we wanted to achieve those objectives with a vapour permeable approach that would prevent condensation from damaging the fabric of the building while providing a healthier and more comfortable indoor environment all year round.”
Refurbishment and New Extension
Natasha researched recyclable, sustainable and natural materials for all elements of the specification, seeking insulation specifically designed for retrofit installations in traditionally-constructed properties. She was delighted to find that the needs of both the wall and roof build up could be met within the Pavatex range for the refurbishment and new build elements of the project.
For the existing property, 120 mm Pavaflex was used to insulate between the ceiling joists, with 200 mm Pavaflex used between the rafters in the roof space. For the walls, Pavadentro, a hygroscopic internal wall insulation developed specifically for retrofit installations, was mounted onto the stud walls and finished with a lime plaster.
The extension is a single storey addition that adjoins the existing listed building and has extended three metre ceiling heights to complement the grandeur of the original property. The structure was constructed using clay blocks filled with insulation and wrapped with an external installation of 120 mm Pavatex Diffutherm; a woodfibre insulation board designed for mechanical fixing to the external building envelope. The internal walls were also insulated using Pavaflex within the stud wall structure and the roof has also been heavily insulated with products from the Pavatex range, with 220 mm of Pavaflex followed by 800 mm of Pavatherm; an insulating sarking board designed as a base for cladding or tiling.
Exceptional Thermal Performance
The project has included installation of an MVHR (mechanical ventilation with heat recovery) unit to aid building comfort and further enhance the energy efficiency benefits of the building’s exceptional thermal performance.
Natasha adds: “Not only does the finished building retain heat so that we barely need to heat it on cold days, it’s also pleasantly cool in warmer weather. Soprema has worked with us throughout the design process and the installation to ensure correct product selection and installation. The result is a family space that meets all my expectations in terms of sustainability and energy efficiency while offering us a home that’s simply a lovely place to spend time in.”