Sky House | Klas Hyllen Architecture

“Sky House stands as part of a new generation of exemplary environmental retrofits in the UK; projects that prioritise reuse and recycling to dramatically reduce embodied carbon compared with new construction.” - Klas Hyllen

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Sky House is nestled within a secluded hollow on a hillside in South West England, commanding breathtaking views across the rugged landscape. To the south, the land drops steeply away, leaving the horizon dominated by sky; a constantly shifting canvas of English weather that the design seeks to capture and celebrate.

This is a transformation of a tired 1970s dwelling to better suit modern family life that creates a home environmentally fit for the 21st century. Within its protective new envelope of super-insulated walls and triple-glazed windows, the house now offers exceptional thermal performance while preserving the original structural core.

This deep retrofit transforms what was once a confusing tangle of interlocking spaces into a clear and elegant composition of two distinct volumes: a primary living space and a secondary bedroom section. Between them, a transparent link connects the two, framing views and light.

ENVIRONMENTAL RETROFIT
Sky House stands as part of a new generation of exemplary environmental retrofits across the UK; projects that prioritise reuse and recycling to dramatically reduce embodied carbon compared with new construction. Sky House has an embodied carbon reading of only 266 kgCO2e/m2, comfortably meeting the RIBA 2030 Climate Challenge.

Here, the vast majority of the original building fabric has been retained. Layers of new insulation and re-cladding have transformed both the house appearance and performance. Upon completion, the house achieved an airtightness result of 1.9 m³/(h·m²) at 50 Pascals — a remarkable figure given the complexity of the original form, site layout, and the challenges of upgrading 1970s cavity walls.

Sky House demonstrates what can be accomplished through rigorous detailing and collaboration. Designed to achieve a 90% reduction in operational energy use, the project bettered this on completion, and in its first year of use operated on only 36kwh/m2/year.

All residual energy demand is met through a fossil-free air-source heat pump, whilst an MVHR system ensures consistent indoor temperature, excellent air-quality and stable humidity levels throughout the year. The result is a home that performs exceptionally - it is warm, comfortable, and deeply connected to its landscape.

MATERIALS
The exterior is clad in a refined palette of pale buff Creeton limestone and whitewashed British larch, anchored by a dark grey slate roof. Each material has been carefully detailed to emphasise natural texture and depth, responding to changing sunlight and shadow throughout the day.

Inside, the home continues this dialogue of texture, light, and views where the result is a composition that balances contemporary minimalism with warmth, colour, and playfulness.

Credits
Architecture Firm: Klas Hyllén Architecture
Lead Architects: Klas Hyllén, Jason Cope

Photography: Dave Watts Photography - https://wattsdave.com/