Energy Efficient Home | Jackson Builders

Kernanderry: Contemporary, energy-efficient timber home.

Project Overview
Shortlisted for two BuildIT 2024 awards and featured in the BuildIT magazine (June 2025 – Build It), our Kernanderry project represents a modern approach to sustainable construction. The project set ambitious targets for carbon reduction, fabric efficiency, and renewable energy integration, showcasing how contemporary design can achieve eco-friendly outcomes without compromising on comfort. Jackson Builders were awarded the project on the recommendation of Lapd Architects (lapd Architects) who we had worked with previously successfully delivering energy efficient homes

Objectives and Goals
Our client, Vincent’s main aim of the project was to replace a dated 1930’s property with poor insulation and high running costs with an energy efficient, sleek modern home defined by clean lines, lots of natural light and a contemporary palette – anthracite windows, timber cladding and gleaming render.

Before the Project
Kernanderry was envisioned as an energy-efficient home from the ground up, focused on achieving significant reductions in both carbon emissions and heating demand. It took 8 months for the project to secure planning with surveys required for ground contamination and ecology.

Scope of Work
Demolish the existing property and replace ground up with a new, timber frame property with double garage and office scape, both fully finished inside and landscaped externally.

Achieve U-values of 0.14 W/m²K – walls and floor achieved 0.14, roof achieved 0.09.
Integrating a 5.20 kW photovoltaic (PV) array to generate renewable energy, reducing grid dependency and emissions.
Installing triple-glazed windows and doors with U-values as low as 0.79 W/m²K to minimize heat loss.
Equipping the property with a Mechanical Ventilation with Heat Recovery (MVHR) system, which boasts 87% efficiency, ensuring excellent air quality while conserving energy.

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Challenges and Solutions

“Jackson Builders is a very good company, they had someone here every day and they never missed a deadline.”

The presence of bats meant that we could only demolish the house once a new 20m2 bat house had been built and when their nesting period (May to September) had come to an end.

Vincent moved into a caravan onsite and we demolished the house. When we had to move the electricity supply with your engineer connecting the fuse-board and the local electricity supplier working on the meter. Despite meticulous planning, the local engineer didn’t arrive leaving Vincent in a caravan with no power in the middle of winter! With much wrangling we negotiated for an engineer to attend over the weekend to get the power on – it wasn’t a great start but we did everything we could to resolve the situation quickly.

In addition to the bats, the project had ambitious energy efficiency targets which we had to meet which required meticulous planning and attention to detail. One challenge was meeting the high insulation and airtightness standards necessary, the timber frame incorporated 180mm thick insulation and every seam was painstakingly taped.

The original brief used Siberian larch for the external cladding but we couldn’t source it due to the war in Ukraine so we used UK grown cedar instead which was harvested and sawn within 20 miles of site.

Results and Outcomes
The completed Kernanderry project exceeded energy efficiency expectations, with significant reductions in heating demand and CO₂ emissions. Vincent says “It’s very airtight and warm, and the MVHR creates the perfect healthy environment inside. My energy consumption is less than that of a typical one-bed house ad my energy bills have dropped significantly compared to the old 1930s property. It’s generally a much more comfortable home to live in.”

While the project falls slightly short of full Passive House certification, Kernanderry remains a leading example of sustainable construction, balancing modern luxury with environmental responsibility and was recognised within the industry with two nominations at the 2024 Build It Awards

Client Feedback
Reflecting on the project, the client commended Jackson Builders for our project management and responsiveness. The entire build took 42 weeks to complete with monthly project meetings with all stakeholders. “These regular meetings helped keep the project on track. Jackson’s is a very good company and had someone here every day, sometimes on weekends. They never missed a deadline”.

Planning a self build project?
Are you looking to self build a home in Oxfordshire? Jackson Builders are your trusted partner in creating bespoke homes in Oxford that reflect your vision and style. With a reputation for excellence, we specialise in working closely with architects and homeowners to bring ambitious plans to life. Whether you’re an architect looking for a reliable construction partner or a homeowner ready to embark on your dream build, Jackson Builders is here to turn your ideas into reality – learn more here: Our Approach to Self Build Homes