BACA architects | Projects | Misty River House

Background

The Misty River House is an existing residence in Henley upon Thames. The homeowners appointed us to replace the current substandard dwelling with a carefully designed amphibious home that improves the appearance of the riverfront and provides a resilient response to local flood risk. The site is within the local Greenbelt but does not fall within a conservation area.

The new dwelling is conceived as an amphibious house. This type of building rests on the ground within a purpose-designed dock and rises only during extreme flood events. The approach provides additional flood storage beneath the structure, reduces risk to neighbouring properties and offers a more natural connection between the house and the ground plane. It avoids the redundant void that would occur if the replacement dwelling were built on stilts and ensures the home remains above the highest potential flood levels.

We previously delivered the first amphibious house in the United Kingdom in Marlow, Buckinghamshire. That project is widely recognised as a leading example of flood mitigation design in sensitive riverside settings.

Process

The project brief focused on creating a high-quality replacement dwelling that achieves low energy use, strong environmental performance and long-term climate resilience. Extensive analysis and modelling informed the amphibious strategy, ensuring that the new structure will lift safely during rare flood events and return to its original position once floodwaters recede.

A whole life carbon assessment was undertaken to determine the sustainability benefits of replacing the existing property. The assessment demonstrated that the embodied carbon of the new dwelling is lower than the cumulative carbon impact associated with refurbishing the current building following future flood events over a projected seventy-five-year lifespan.

The landscape strategy supports a ten-percent ecological gain on site and works in harmony with the amphibious dock structure to allow water to move naturally during extreme events.

Architecture

The replacement dwelling is planned as a contemporary, low-energy home constructed from high-quality materials. The structure combines an oak timber frame with lime-rendered structurally insulated panels. This approach brings together traditional craftsmanship and modern construction methods while improving thermal performance and reducing operational energy demand.

The building follows the energy hierarchy of lean, clean and green. The design achieves a significant reduction in carbon emissions compared to the current Part L Building Regulations. The architectural form and material palette are intended to sit comfortably within the riverside setting and to improve the overall riverfront frontage.

Overall, the new amphibious house provides a carefully considered addition to the Henley-upon-Thames river corridor. It offers a low-carbon, high-quality architectural solution that responds sensitively to its setting and will protect its occupants from flooding well into the future.