Les eco logis-en

1. 162
The combination of wood and
stone gives charm to a typical
farmhouse.
Key dates
The farm dates back to before
1900.
Beginning of the plans : 2006
Planning permission secured :
2010.
Works : 2011 to 2012.
In order to preserve the stone farmhouse they inherited from their parents,
Anne and Michel wished to renovate it. They have given it a second life
by creating 5 holiday lets. To give the holiday units a more contemporary
look, they wanted to marry ancient materials taken from the site with
21st century ones, without losing the essence of the location. The Eco-
friendliness of the dwellings is shown through the use of recyclable or
reused materials (stones, beams, doors) as well as natural heating and
sanitation systems.
Introduction
Saint Brieuc
Quimper
Vannes
Rennes
Baden
Les Eco-Logis
Overview - Photo © Servane Guihaire - Constructys Bretagne

2. www.libnam.eu 2
Context
The owners crated a limited
company (SARL) called Les Eco
Logis de Lairmarc’h, enabling them
to offer visitors welcoming, easy to
heat and eco-friendly holiday lets.
The project is in a fairly popular
tourist area: Le Golfe du Morbihan,
between the sea and countryside.
The buildings are south facing.
The T – shape enables 3 of the lets
to be south facing while the other 2
are west-facing.
The proximity of the coast means
that the Local Plan Area is restrictive,
and the only possible change of
use for the building was to holiday
accommodation and the only
contractor accepted was a farmer.
These holiday dwellings, covering
an area of 370 sq m (3980 sqft) are
attached to, and in close proximity,
to the farm; privacy was therefore
a requirement put forward by the
architect. Therefore, the layout
was also influenced by the desire
to keep cars away to make the
site wheelchair friendly. One of
the lets is especially converted for
disabled people, as laid out in the
regulation for disabled access (law
of 11/02/2005).
Plan © A’Dao
N

3. French-British collective Libnam3
Building overview
Two different systems were used
for the renovation ; the existing
buildings are in stone while the
extension is timber-framed.
The stone buildings are on shallow
existing foundations. The internal
solid wall was insulated by blowing
15 cm of cellulose fibre and covered
by gypsum boards (Fermacell).
Where there was a higher risk of
damp, walls have been insulated
with cork.
The timber frame is made of
pinewood beams (45x145 mm) and
laid on a concrete slab, which is
insulated underneath by sheets of
polyurethane 10 cm thick (Sporema
brand). The wall insulation is made
of cellulose fibre, applied between
timber posts, and covered by
chipboard to assure continuity of
the outer-shell.
The distribution of the internal
layout is made of steel frame and
plasterboard (BA13) or gypsum
boards (Fermacell), using wood
wool as an insulator.
The window and door frames were
tailor-made by MC France. They are
made of wood and steel, and double
glazed. They do not come with
rolling blinds as they would look
inappropriate on listed buildings
and would create thermal bridges.
The holiday lets are all equipped
with a wood burner with different
capacity depending on the area to
heat. Electrical heating can be used
when necessary. However, in order
to promote the use of renewable
energy, the wood is provided for
free while electricity is charged on
top of the rental price.
Framing - Photo © Yann Denion - CICS

4. www.libnam.eu 4
The ventilation is a Hygro B
type (outlet and inlet air hygro
adjustable).
A 10 m3 water tank was installed
to recover rainwater for watering,
toilets and washing machines
(situated in the communal laundry
at the entrance). The water sewage
treatment is done by phyto-
purification ponds.
Structure of the roof, from outside
in : slates - battens - cellulose fibre
- vapour barrier - gypsum boards
(Fermacell).
Structure of the stone walls : Stone
- Whitewash - rain barrier - Douglas
fir frame - 15 cm thick cellulose fibre
- vapour barrier - gypsum boards
(Fermacell).
Structure of the partition walls : 22
mm Douglas fir cladding - battens
(thermal gap) - Wood fibre boards (6
cm Pavatex) - Rain barrier - Bracing
pannels (18 cm OSBracing) - 15 cm
insulated frame - Vapour barrier -
Gypsum boards (Fermacell).
Timber-framed extension - Photo © Servane Guihaire - Constructys Bretagne

5. French-British collective Libnam5
Technical focus :
Stone and insulation
Cellulose fibre (made of recycled
newspapers) is commonly used
as insulation for timber frame
buildings, but more rarely for stone
buildings.
The cellulose fibre used on site (by
Isocel) is produced by a company
called Celaouate in Morlaix, from
recycled local papers such as Le
Télégramme, which ensures a low
carbon footprint due to its local
production.
As well as cellulose fibre’s insulating
quality, it has greater thermal mass
than mineral wool. This makes it
a useful product to reduce the
temperature difference inside
the building, in particular during
heat waves. Married with stone,
cellulose fibre provides comfort in
the summer time, and the holiday
lets are used mainly during warm
months.
Here, the cellulose fibre was blown
into the wooden frame and sealed
by a vapour barrier. The device
blows the cellulose fibre through an
opening in the vapour barrier which
is then tightly sealed. Moisture
must not reach the insulation. This
requires careful implementation
in respect of the stone, such as
pointing the outside walls and the
protection of the lower parts. For
example, rain barriers have been
applied at the bottom of walls and
loose cork was put in the areas most
exposed to capillary rise.
It is important to note that borax is
integrated into cellulose fibre. This
mineral has fire retardant properties
and enables protection from fungus
and rodents. In 2012 and 2013, in
France, the public health safety of
this additive caused controversy. For
Interior - Photo © Servane Guihaire - Constructys Bretagne

6. www.libnam.eu 6
Barriers and solutions
On a legal and regulatory level,
several problems were encountered.
For example, the site is situated
in a conservation area, so it was
necessary to communicate with
Architecte des Batiments de France
(French equivalent of English
Heritage), especially for the creation
of West-facing openings and the
modification of the facade.
To put the phytopurification (water
treatement using a reed bed) in
place, it was necessary to explain
to the Syndicat Intercommunal
d’Alimentation en Eau Potable
(Local water board) what the system
was about. The constant evolution
of the techniques can bring
misunderstandings from regulation
bodies which can slow down eco-
construction. This is one of the
reasons why companies have to
keep training to obtain certificates
as well as skills.
For the cellulose fibre, the company
CICS underwent training with
different organisations: Domus
a while, building regulations used
ammonium salts, but finally chose
to reinstate the use of borax; and
for good reasons since ammonium
may degrade into ammonia and this
has potential health risks, whereas
borax has been judged to have a
low impact, below a 5% threshold.
The cellulose fibre industry has
however decided to start research
work to identify substitute to these
salts.
Bedroom - Photo © Servane Guihaire - Constructys Bretagne

7. French-British collective Libnam7
(supplier), Tyeco2, Ecolusis and
ARFAB (airtight). They also attended
training in Energy-saving in the
building industry.
Monitoring by the main contractor
onsite,discussionswiththearchitect,
and regular site reports allowed
better communication between the
trades, even if it did not avoid all the
problems. For instance, there was a
large turnover of employees in one
company which complicated the
passing down of some instructions.
However, to reach the target thermal
performance, each contractor had
to pay attention to the work of
others.
There are many technical constraints
that guided the homeowners’
choices : lime and hemp concrete is
interesting in terms of insulation but
wouldhaveresultedinwallsthatwere
too thick ; a heat-recovery device
would have been complicated to
install for 5 independent cottages ;
solar panels would have resulted in
a lot of wiring and trouble during a
possible division of dwellings in the
future.
Finally, a few technical problems
occurred on the building site :
creating weep holes on the cement-
rendered stone walls was very
complicated, the gypsum boards
were heavy and difficult to cut, and
the concrete slab took time to dry
in winter as the building was well
insulated.
Inside - Photo © Servane Guihaire - Constructys Bretagne

8. 8
Stakeholders
Main contractor : SARL Les Eco Logis de
Lairmarc’h (Baden)
Architect : A’Dao (Rennes)
Project manager : Gérard Lucas (Les
Fougerêts)
Masonry : Pelbois (Pluherlin)
Carpentry-Joinery : Burban (Malansac)
Insulation – internal walls : CICS (Saint
Nicolas du Tertre)
Services : SARL Coué Crété (St Martin/Oust)
Plumbing : Lubert (Limerzel)
Electricity : Cornec Pac Elec (Plougoumelen)
Tiling : Roux SARL (Guegon)
Stairs : Potier JP (Rieux)
Decorating : Le Tournel Sarl (La Gacilly)
Wood burners : Nicolas Cheminées
(Lanester)
Landscaping and sewage : Aubat (Landaul)
Phytopurification Conception : Aquatiris
(Landevant)
Link
www.lafermh-baden.fr
Costs
Project management : 8.6% of the global of
the build : £41,167 before tax
Groundwork and connection to services :
£27,526 before tax
Masonry and structural work : £85,315
before tax
Frame : £58,189 before tax
Roofing and waterproofing : £40,644 before
tax
Indoors and outdoors joinery : £54,875
before tax
Electricity and heating : £35,967 before tax
Internal walls and insulation : £71,730
Plumbing : £25,918 before tax
Tiling : £27,430 before tax
Stairs : £9,152 before tax
Decorating : £25,901 before tax
Total : £503,814 before tax, equivalent to
£1,361 per sq m
A partial thermal survey was done
during the study phase in order to
choose the correct materials. The
building did not aim to achieve any
specific eco-labels, the wish being
to make a more energy-efficient
Performance
Perspective © A’Dao
building with environmentally
friendly materials.
Following readings, it was found that
eight people consume twelve euros
worth of hot water and electricity
per week (about 90 kWh).
Contact
Constructys Bretagne
www.constructys-bretagne.fr