Session 1 - Montefiore

PLEA2012 - 28th Conference, Opportunities, Limits & Needs Towards an environmentally responsible architecture Lima, Perú 7-9 November 2012
THE SIMPLIFIED EVALUATION
The simplified evaluation allows an individual user (or
household) to assess energy consumption for home-towork
and home-to school travels and for the heating of
his house on the basis of limited information.
Questionnaire are voluntary very simple to allow the user
to complete them quickly and without specific data.
Energy consumption for transportation
Two pieces of information relating to the location of the
house of the user are needed. On this basis, the mean
home-to-work and home-to-school energy consumptions
are calculated for the considered district. These are given
along with the mean travelled distance from home-towork
and from home-to-school and the mean modal
share in the considered district. To provide these mean
values, a quantitative method was developed to assess the
energy efficiency of home-to-work and home-to-school
travels. The complete methodology and data set are
presented in detail by [7, 13]. This method uses empirical
data from Belgium’s national census, which is carried out
every ten years. We used one-day travel diary data
collected from male and female heads of households
from the two last surveys, respectively carried out in
1991 and 2001. For these households, information about
demographics, socioeconomic status, car ownership,
travel distances, the main mode of transportation used
and the number of days worked per week and per person
is available at the individual (disaggregated) scale. These
data are available for both home-to-work and home-toschool
travels.
Three indexes are derived from this method and used
in the online interactive tool. The energy performance
index (expressed in kWh/travel.person) for a territorial
unit represents the mean energy consumption for hometo-work/home-to-school
travels for one worker/student
living within a particular census block (district). This
index takes into account the distances travelled, the
means of transport used and their relative consumption
rates, expressed by equation (1). In the equation, i
represents the territorial unit; m the mean of transport
used (diesel car, fuel car, train, bus, bike, on foot); Dmi
the total distance travelled by the means of transport m in
the district i for home-to-work (or home-to-school)
travels; fm the consumption factor attributed to means of
transport m and Ti the number of workers (or students) in
the territorial unit i.
(1) Energy performance index (i) = (∑m Dmi * fm) /Ti
Consumption factors fm were calculated by [13] on the
basis of regional and local data. Consumption factors are
worth 0.56 kWh/person.km for a diesel car, 0.61
kWh/p.km for a fuel car, 0.45 kWh/p.km for a bus, 0.15
kWh/p.km for a train and 0 for non-motorized means of
transportation because these do not consume any energy.
The distance index (in km) represents the mean distance
travelled (one way) by one worker/student from home-towork/school.
The modal share index (in %) represents
the frequency of use for each mean of transportation per
territorial unit. Note that the annual energy efficiency of
travels is expressed in kWh to allow for a comparison
between the energy consumption in transport and the
energy consumption in the residential building sector
(heating, appliances, electricity, etc.).
Energy consumption for heating
The common ownership, the size of the house, the period
of construction (or building standard) and the heating
system are needed in the questionnaire of the simplified
evaluation and allow the tool to give the mean heating
consumption of a house corresponding to the
combination of the four criteria. To build the database, a
typology of detached, semi-detached and terraced houses
was established to classify the residential suburban
building stock of the Walloon region of Belgium. This
typological approach also used by [1, 6], is based on the
following factors: common ownership (detached, semidetached
or terraced house), the heated area of the house
in square meters (m²), the date of construction.
Five age categories (pre-1950, 1951-1984, 1985-
1995, 1996-2011 and after 2011) are considered, based
on the evolution of regional policies concerning building
energy performance and the evolution of construction
techniques. These age categories are used to approximate
a mean thermal conductivity of external façades from a
“standard” composition of walls, slabs, roofs and glazing
attributes for buildings in each category (Table 1). Three
additional categories are added for houses built according
to standards higher than the European Energy
Performance of Buildings Directive (EPBD). These are
the low-energy standard, the very low-energy standard
and the passive standard which respectively correspond
to annual heating requirements lower than 60
kWh/m².year, 30 kWh/m².year and 15 kWh/m².year.
Using this classification, an energy consumption
analysis is performed with thermal simulation software
(TAS) that includes a three-dimensional modeller and an
interface for the input of thermal information (climate
conditions, building materials, internal conditions,
periods of use of the house, etc.). The energy required to
heat each type of building was modelled. Cooling
requirements were neglected because they are minimal in
Belgium. Indeed, the Belgian climate is a temperate
climate. The mean temperature for the typical year used
in the simulations is 10.3°C. The maximum and
minimum temperatures, for the considered year are 34.9
°C and -9.1°C.
Primary energy is provided in the results to heighten
public awareness on the impact of the heating system on
the environment. Energy consumption for heating are
converted in primary energy by applying efficiency
coefficients according to the heating system. Coefficients
come from the DPEB (Annex I).