FACT SHEET
The Maintenance-Free House - tradition
Developer:
Location:
Type of building:
Area:
Year built:
Architect:
Engineer:
Contractor:
Consultant:
Knowledge partners:
REALDANIA BYG A/S
NYBORG, DENMARK
PRIVATE RESIDENCE, SINGLE FAMILY HOME: One level with an open
kitchen/family room, bathroom and 3 bedrooms, as well as technical room
136 m2
2013
LETH & GORI
BURO HAPPOLD ApS
EBBE BERNTH MURER & TØMRER
THE DANISH TECHNOLOGICAL INSTITUTE, MASONRY, BUILDING AND
CONSTRUCTION
DANISH BUILDING RESEARCH INSTITUTE - AALBORG UNIVERSITY, DANSKE
TEGL, NINI LEIMAND, THE ROYAL DANISH ACADEMY OF FINE ARTS, SCHOOL
OF ARCHITECTURE – INSTITUTE 2
Description
The Traditional Maintenance-Free House is part of a large development project; The MiniCO2 Houses. The
project includes a total of six detached houses, each of which illustrates various aspects of the reduction of
CO2 emissions in the construction, operation and maintenance of a house.
The Maintenance-Free House focuses on "Maintenance and Service Life" and examines how much CO2 can
be saved when a house is constructed in such a way that it has a lifetime of at least 150 years, and the
building envelop does not need to be maintained during the first 50 years of the house's service life. House
A – described here – has been constructed using traditional materials, which have proven their long service
life. House B has been constructed in new materials, which are expected to have a long service life.
The Maintenance-Free House A has thus been constructed according to building techniques that have
proven their longevity through centuries. The material is first and foremost red brick, i.e. clay that has
been lifted from the ground, shaped into bricks and burned, and then masoned using mortar, as houses in
Denmark have been built for almost 1,000 years. The house is equipped with glass doors and windows the
height of the façade and with a tiled hip roof. The house rests on a plinth that functions as a covered
veranda protected by the roof's immense overhang all the way around the house.
Inside, The Maintenance-Free House has been designed in the form of a living organism with spatial niches,
pockets, recesses, curvatures, intermediate zones, etc. In its design, the house bears a similarity to a city –
with the common room as the open space; the open, transilluminated room with high ceilings, where it is
possible to look from façade to façade and from gable to gable, and with the rooms which are intimate and
embracing buildings that intersect the streets of the city and open space.
Robust and simple solutions for known problems
The house is especially supported by two crucial elements, which in turn ensure a wide range of benefits: A
woven brick wall and a large projecting roof.








The exterior walls are massive brick walls constructed without the use of vapour barriers and
insulation. The walls have been woven together by large brick blocks in the back wall, which
insulate using a multitude of small cavities, as well as by traditional bricks in the façade masoned in
a so-called half stretcher bond with headers that have been cut into the brick blocks positioned
behind. The traditional bricks ensure a maintenance-free and long-lasting outer surface.
The one-material construction shields against damage. Different materials will move differently
with temperature fluctuations, and over time this often leads to cracking with subsequent damage.
The simple wall, on the other hand, moves uniformly and is not prone to destruction.
Thanks to the use of brick and the simple construction without vapour barriers, the wall is a
diffusion-open structure, which can absorb and discharge moisture so that fluctuations in humidity
are neutralized - resulting in a healthier indoor climate.
The weight of the wall enables it to store heat during the winter and coldness during the summer
and makes it possible to compensate for temperature fluctuations between day and night, again
for a better indoor climate.
The interior surfaces consist of brick blocks, sand filled walls and wooden panels; all surfaces that
do not require ongoing maintenance in the form of painting or similar.
The roof has been designed as a collar roof without penetrations of the roof surface. It is steep, so
water flows quickly away, thereby minimizing the risk of damage.
The insulation in the roof is of paper wool, which has good moisture-wicking properties, makes the
use of vapour barriers superfluous.
The roof is fitted with an approximately 1 meter wide eave on all four sides. The eave protects
masonry, doors and windows so that the climate envelop of the house will actually be able to last
for 150 years without having to be maintained during the first 50 years.
Savings
CO2 emissions from the material consumption for the life cycle of the design in The Traditional
Maintenance-Free House is in line with a normal average house; The Reference House (both are at 5 kg
CO2/m2/year for a period of 50 years). In other words, ensuring the housing a longer service life and less
maintenance demands has not been at the expense of CO2 emissions.
The long service life may result in the house lasting at least twice as long as a normal house. In this case the
savings will of course be substantially greater.
In The Maintenance-Free House A, the replacement cost of materials over 5 years is calculated at
approximately 0.4 kg of these 5 kg of CO2 compared to approximately 0.6 kg of the 5 kg in The Reference
House. Therefore, the CO2 saving effect of low maintenance is not so great in itself. This is due to the fact
that the most CO2-intensive building elements such as foundations, glass and mineral wood insulation
rarely require maintenance, whereas the parts which can normally require replacement during the course
of the house's service life – doors, windows, interior surfaces, etc. – are relatively "light" in the CO2
context. However, it can be seen that although small, this part of CO2 emissions is 30% below The
Reference House, and this points to the effect of a good overhang and robust surfaces both outside and in.
It is also worth remembering that for the owner of the house, low maintenance on these means less
frustration and money saved for craftsmen and materials.
The large amount of bricks in The Maintenance-Free House means that in particular the exterior walls make
up much of the CO2 calculations. Although the roof construction also consists of a large area covered with
tiles, the CO2 contribution from this is not so large, because the roof also contains a large amount of CO2binding wood, both for the load-bearing structure and for the fixed roofing underlay. In addition, paper
wool has been used for ceiling insulation.
All in all, the results show that if construction and design lead to an extended service life for the house as a
whole as they have been carried out in The Maintenance-Free House A, they will result in a favourable CO2
calculation seen over the total service life.
About the development project The MiniCO2 Houses
The Maintenance-Free House is one of six demonstration houses that have been constructed in the coastal
town of Nyborg. Five of the houses examine various ways of reducing CO2 emissions, while the sixth house
brings these experiences together.
The efforts of the construction industry against CO2 emissions have focused on energy for heating – for
good reason – and thus air tightness and insulation. However, concurrently with the constantly tightened
national and EU-established requirements for precisely this area, it becomes relevant to determine how
construction can also reduce CO2 emissions, e.g. in relation to materials and in relation to user behaviour.
The main objective of the development project The MiniCO2 Houses is to reduce CO2 emissions in the
construction, operation and maintenance of a house respectively.
The six houses are based on the same overall frameworks:
• Building Type: Single family home
• Size: 130 to 172 m2
• Energy framework: The 2015 Standard
• Budget: Normal economy
• Architectural design: Broad appeal
• Future: Sale of the house after completed experiment
FACTS about the six MiniCO2 Houses

The Adaptable House must demonstrate the importance of "flexibility and changeability", i.e.
how much CO2 can be saved if a house has been designed and fit out in advance with minimal
consumption of materials to be able to handle the changing needs and requirements that a family
typically has for a home through life.




The Upcycle House must demonstrate the importance of "Recycling and Upcycling", i.e. how
much CO2 emissions can be saved when recycled and upcycled materials are primarily used for the
construction.
The two Maintenance-free Houses must demonstrate the importance of "maintenance and
lifetime", i.e. how much CO2 can be saved by not having to maintain a house during the first 50
years. The two houses are constructed for a lifetime of 150 years, which is equivalent to two and
three times the life of an ordinary single family home. The one house is constructed of traditional
materials, which have been tested through the centuries. The second house is constructed from the
materials of today and tomorrow.
The Quota House must demonstrate the importance of "occupant behaviour and consumption
patterns", i.e. how much CO2 can be saved when the behaviour of the occupants is supported and
assisted by well thought-out design, technology and not at least by a quota - a kind of budget
account - which by means of monitoring and feedback sets a clear, reduced target for the amount
of CO2 emissions that the occupants emit per month.
The MiniCO2 Prototype House brings together and balances the experiences and the results of the
previous houses and develops a MiniCO2 Prototype House with the smallest possible CO2 footprint
and widest possible architectural appeal on normal commercial terms and within a general
economic framework.
About Realdania Byg
The property company Realdania Byg A/S is a subsidiary of Realdania. The objectives of Realdania Byg are
to develop and communicate a collection of good examples of building styles and architecture from
different periods and regions of Denmark. Realdania Byg thus functions as Realdania’s skills centre within
the area of “development and conservation of property”. Realdania Byg has two areas of activity:


On the one hand, the company invests in listed buildings and buildings worth restoring, which are
then restored with respect for the property's architecture and history.
On the other hand, Realdania Byg is active in new construction with a focus on development and
innovation.
Read more at: http://www.realdaniabyg.dk/english
For more information
Project Manager Frants Frandsen ff@rdbyg.dk and Jørgen Søndermark jso@rdbyg.dk Communications
Manager Anne Dorthe Walther adw@rdbyg.dk
Captions and photo credits