Clachan Seil, Oban — 2026

Rock Cottage

Replacement Bedroom Wing and High-Performance Retrofit

Back to extensions and alterations

When returning clients purchased Rock Cottage on a spectacular site overlooking the waters around the Isle of Seil, they asked us to re-evaluate the original part of the house. The existing accommodation comprised six bedrooms that no longer suited their needs, and the brief evolved into creating a more comfortable, spacious and energy-efficient home centred around a luxurious master suite and guest accommodation.

When returning clients purchased Rock Cottage on a spectacular site overlooking the waters around the Isle of Seil, they asked us to re-evaluate the original part of the house. The existing accommodation comprised six bedrooms that no longer suited their needs, and the brief evolved into creating a more comfortable, spacious and energy-efficient home centred around a luxurious master suite and guest accommodation.

Rebuilding for Long-Term Comfort

The original cottage was constructed using Dorran pre-cast concrete panels and had previously been incorporated into a major renovation undertaken in 2010.

Investigation revealed concerns around moisture within the floor structure, and it was not possible to guarantee that these issues could be fully resolved through alteration alone.

The decision was therefore taken to replace the original cottage with a new building on the same footprint, creating an opportunity to deliver exceptional levels of comfort and energy performance.

The new accommodation includes two en-suite bedrooms, a laundry room and a generous master suite comprising a bedroom, snug, two dressing rooms, bathroom and sauna.

Rebuilding for Long-Term Comfort

The original cottage was constructed using Dorran pre-cast concrete panels and had previously been incorporated into a major renovation undertaken in 2010.

Investigation revealed concerns around moisture within the floor structure, and it was not possible to guarantee that these issues could be fully resolved through alteration alone.

The decision was therefore taken to replace the original cottage with a new building on the same footprint, creating an opportunity to deliver exceptional levels of comfort and energy performance.

The new accommodation includes two en-suite bedrooms, a laundry room and a generous master suite comprising a bedroom, snug, two dressing rooms, bathroom and sauna.

Architecture Shaped by Light and Views

A gallery-like corridor forms the spine of the new extension, with windows overlooking the garden and space for artwork, books and collected objects.

The roof plays a central role in the design, utilising exposed Douglas fir scissor trusses to create dramatic internal volumes.

Motorised Velux rooflights bring daylight deep into the plan, enhancing the sense of space and connection to the landscape.

Triple-glazed timber windows with aluminium cladding frame views of the surrounding scenery while providing excellent comfort and thermal performance.

A Fabric-First Approach

The building has been designed around exemplary building physics and long-term durability.

Timber-frame construction is combined with wood fibre external insulation to create a continuous thermal envelope around walls and roof alike.

By placing insulation outside the structural frame and roof structure, thermal bridges are virtually eliminated.

Existing issues at wall-to-ground junctions were carefully addressed through improved drainage and detailing to prevent future moisture ingress.

Designed for Wellness and Accessibility

All bedrooms are served by fully accessible en-suite bathrooms with wet-floor showers.

Underfloor heating throughout provides gentle, even warmth while significantly reducing energy demand compared to the previous construction.

Natural slate roofing replaces the original concrete roof tiles, while durable Lindab steel rainwater goods ensure longevity and low maintenance.

The inclusion of a sauna with both conventional and infra-red heating options and carefully considered accessibility features reflects the project's emphasis on comfort, wellbeing and ageing in place.

Outcome

Rock Cottage demonstrates how rebuilding can sometimes offer a better long-term solution than alteration alone. Through a rigorous fabric-first approach, thoughtful planning and a focus on comfort and wellbeing, the project creates a highly efficient home tailored precisely to its owners' needs.

As construction nears completion, the house is already delivering on its ambition to provide exceptional levels of comfort, performance and enjoyment within one of Scotland’s most beautiful coastal settings.