The document summarizes the ambitious project of Kevin McCabe to build Dingle Dell, which is being called Europe's most significant cob building. McCabe aims to build a 10,000 square foot family home using low-impact materials like cob to achieve high energy efficiency standards. The multi-year project has faced challenges from weather delays and funding issues, but McCabe's expertise and innovative use of materials like cob pillars is pushing design boundaries to create a showcase for sustainable architecture.

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Devon’s own cob castle.
Dingle Dell has attracted the attention of the world. Builders and the
public alike are following the build of what has been identified as
Europe’s most significant cob building with bated breath.
Dingle Dell is a Devon man’s dream coming into fruition. Kevin McCabe’s
skills are now world renowned ; but still not content that he had reached
the pinnacle of what he could achieve, he decided to embark on this truly
astounding project. He is doing so under the watchful eye of the media.
Grand Designs, a British programme that follows some innovative and
unusual builds and renovations, is making the journey with him.
Introduction
Truro
Exeter
Ottery St Mary
Dingle Dell
Key dates :
Planning permission : March
2010.
Build : 2011 – expected
finish 2015.
Exterior - Photo © Servane Guihaire - Constructys Bretagne

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Kevin’s aim is to build a family house,
whilst testing the limitations of low
impact materials and endeavouring
to use some of the Passive House
standards to try to achieve CODE
Level 6 accreditation. He is using
over 30 years of experience to help
him achieve this ambitious project.
He would like the building to be a
showcase for British architecture and
so he applied for planning permission
under previous legislation, Planning
Policy Statement 7, which allows
exceptions to normal planning policy
for sustainable development in
rural areas. To gain this, the design
had to be outstanding, innovative
and ground-breaking in its use of
Context
materials or methods of construction.
To help him work towards this aim
Kevin worked with several different
architects and professionals across
the construction spectrum including
structural engineers, renewable
technologies experts, drainage
experts, an ecologist, and local
planners. Ultimately, Dingle Dell’s
palatial size and sweeping curves of
cob and glass combine the traditional
with the modern aesthetic, and is a
worthy of the special permission
granted.
Kevin’s dedication to the project is
demonstrated by the fact that he has
worked 70 hours a week over the past
Plan © Kevin McCabe

3. French-British collective Libnam3
three summers to try and achieve
his goal, making the most of what
good weather he could, although an
extraordinary amount of rain in 2013
- 2014 hampered his efforts.
Dingle Dell is to be 10,000 sqft,
double the size of Kevin’s current
home. The building will comprise of
two cob roundhouses. The larger of
these will be over three floors and
will be the family’s main living space
with a music room and games room
in the basement. The smaller will be a
self-contained living space for guests,
with the basement used for storage
and a cider press! The two are joined
with an enclosed glass walkway with
a fully functional greenhouse in the
middle.
The building of Dingle Dell
commenced in spring 2011 by
excavating 5,000 tonnes of soil, this
not only made way for foundations
but provided the main material
Building overview
Exterior - Photo © Servane Guihaire - Constructys Bretagne

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needed to make the cob. The trench
system foundations for walls stretch
for ¼ of a mile and are filled with
eco concrete, with a reduced cement
content by using by-product from
coal fired power stations, and topped
with a mixture of lightweight concrete
blocks. The cob was laid on the block
base in lifts to create the enormous
walls. The centres of the roundhouses
have circular enclosures housing
helical staircases, and the outer cob
walls are also wrapped in polystyrene
for added insulation and covered
with lime render.
The structural strength for the roofing
is provided by using Glulam beams.
12 x 9 m lengths were used for the
main roof and were cut in a mixture
of concave, convex and straight to
create the undulating, organic shape
intended to blend effortlessly with
the surrounding hills. The roof will
be covered in polystyrene to create
an insulating waterproof base for the
planted meadow finish.
Kevin’s heating is via a heat recovery
system with approximately 700 sq m
of underfloor heating. Approximately
200 sq m is not heated, but a
significant factor for this, is the fact
that cob acts as a thermal store.
The power is provided by a 10 kW
Photovoltaic array which was
installed on the barn roof prior
to the government deadline in
Exterior - Photo © Servane Guihaire - Constructys Bretagne

5. French-British collective Libnam5
December 2011, so that Kevin could
take advantage of the feed in tariff
available at the time.
What is evident about this build is that
Kevin has pushed the limits of both
design and the use of materials to the
extreme, working in an experimental
but intelligent fashion. His love of
building with cob and its sculptural
Technical focus:
Using Cob Pillars
nature and strength has encouraged
him to push the boundaries. Not
many would think to make pillars from
cob. Kevin used pillars in building the
barn and also for the walkway of the
main house.
The supporting pillars for the main
house’s walkway are 550 mm in
diameter and the tallest is 5 m high.
The construction of the pillars was
done in the same way as the walls.
The foundations were put down to
stable ground, and then filled with a
concrete base, upon which the plinths
were built from natural stonework.
The cob is made from clay, straw,
Interior - Photo © Servane Guihaire - Constructys Bretagne

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sand and water to bind the materials
together, then, placed on these round
plinths in lifts in the same way as a
cob wall is constructed. However,
the lifts for the columns were smaller,
only 300 mm, and were done using
a mould to keep the shape and then
finished by hand.
Each cob pillar is holding up several
tonnes. The cob can cope with this
as it is compressively strong but prior
to the build testing was done by
engineers. During testing for the cob
pillars, the cob withstood a force of
1.6 newton’s, the engineer then used
a figure of 1.1 N for build calculations.
Once built, before any load bearing
was allowed to take place, the pillars
were checked on site by his structural
engineer, Barry Honeysett.
Exterior- Photo © Servane Guihaire - Constructys Bretagne
Cross section © Kevin McCabe

7. The building process for Dingle Dell
has not been as straight forward as
Kevin would have liked. He has been
hampered by the weather. In 2012,
Devon had the wettest summer for
Barriers and solutions
Stakeholders
Client : Rose and Kevin McCabe
Builder : Kevin McCabe www.
buildsomethingbeautiful.com
Architects : Bedford & Jobson www.
architecturedevon.co.uk
Costs
Kevin says that the cost of the build will
eventually be around £500,000, although this
does not take into account his own labour
and using cob from the site which would
more than double this figure, bringing it
closer to a million. Before building, Kevin
had already paid £30,000 to architects,
£30,000 for engineers, and £50,000 on
modelling before planning permission was
given. Building your own cob castle is not
cheap. They say an Englishman’s home is his
castle, and in Kevin’s case, he really will have
one.
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100 years, and this severely restricted
the ability to build with cob. The
prolonged period of the build meant
that money became an issue, so
Kevin had to go back to work on
paid projects to fund the further
development.
Interior - Photo © Servane Guihaire - Constructys Bretagne
Contact
Petroc
www.petroc.ac.uk