Underhill House, a strikingly-modern earth-sheltered home, was the first house in England to
achieve certified Passivhaus status - widely regarded as the word's leading standard in energy
Designed by UK architect Helen Seymour-Smith, Underhill House was developed underneath
and adjacent to a derelict 300-year old barn situated in a prominent and beautiful location on
a hillside in an Area of Outstanding Natural Beauty (AONB) in the Cotswolds.
Sensitive restoration of the existing barn and an innovative design ensured the project has minimal
visual and environmental impact. Not only was the external form of Underhill House designed to
minimise visual impact on the surrounding landscape, the interior finish and construction
materials were carefully chosen to make the building environmentally sustainable.
The project was featured on prime time television programme Grand Designs in 2010
and as a landmark Passivhaus project in Architects Journal.
Dow Building Solutions
supplied a range of STYROFOAM
™-A products - FLOORMATE™-A
ROOFMATE™-A and PERIMATE™ DI-A - to insulate the floor, roof and basement walls
of Underhill House. The materials helped to create a continuous, external envelope of
moisture-resistant insulation and played a key role in ensuring the building achieved
Of the Dow products used in the project, FLOORMATE 300-A
proved to be the real
breakthrough when it came to insulating Underhill House. Because it resists moisture
and has an incredibly high compressive strength, FLOORMATE 300-A
can be used below
a concrete floor slab, a growing practice in residential buildings and one which could
support of more energy efficient buildings in future.
Using the insulation in this way helped to avoid thermal bridges at floor and wall junctions
and meant the concrete structure of the building could be left exposed internally, making
the most of its thermal mass properties. Exposed concrete absorbs heat in warm weather
effectively cooling the buildings, and releases stored heat during cooler weather to provide
a natural heating regime.
Floor: 0.1 W/m2K
Underground walls: 0.11 W/m2K
Roof: 0.097 W/m2K
-A is manufactured using technology that takes CO2 from industry and uses it as
a blowing agent in order to create insulation foam with a Global Warming Potential (GWP)
of less than five.
For more details on STYROFOAM
-A products contact Dow Building Solutions
by email on FKLMAIL@dow.com
and one of the account managers will be in touch
or visit www.styrofoam.co.uk