1. A REVIEW OF DESIGN PROCESSES FOR LOW ENERGY
SOLAR HOMES
Rémi Charron
Abstract
In recent years, there have been a growing number of projects and initiatives to promote the development and mar-
ket introduction of low and net-zero energy solar homes and communities. These projects integrate active solar tech-
nologies to highly efficient houses to achieve very low levels of net-energy consumption. Although a reduction in the
energy use of residential buildings can be achieved by relatively simple individual measures, to achieve very high lev-
els of energy savings on a cost effective basis requires the coherent application of several measures, which together
optimise the performance of the complete building system. This article examines the design process used to achieve
high levels of energy performance in residential buildings. It examines the current design processes for houses used in
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
a number of international initiatives. The research explores how building designs are optimised within the current design
processes and discusses how the application of computerised optimisation techniques would provide architects, home-
builders, and engineers with a powerful design tool for low and net-zero energy solar buildings.
K e y w o r d s : Optimisation, Low and net-Zero Energy Homes, Cost Effective Design.
INTRODUCTION design configurations. This can be observed by
examining net-zero and low energy building
Homes that combine energy efficiency with passive demonstration projects from around the world
and active solar technologies can significantly (Charron, 2005). These projects depended on trial-
reduce their overall energy consumption and can and-error optimisation using dynamic energy simu-
be referred to as low energy solar homes (LESH). In lation tools, coupled with the knowledge of the
the last 25 years, there have been many one-of-a- designers. Simulations are normally used in a sce-
kind demonstration projects and international ini- nario-by-scenario basis, with the designer generat-
tiatives that have promoted the development of ing one design and subsequently having a comput-
LESH and in some cases, net-zero energy houses er evaluate it. This can be a slow and tedious
(ZESH). An acceleration of their adoption has been process and typically only a few scenarios are eval-
witnessed in the last few years as countries are start- uated from a large range of possible choices.
ing to implement measures to reduce greenhouse Although a reduction in the energy use of residen-
gas emissions to address global warming. In the tial buildings can be achieved by relatively simple
context of this paper, the difference between a LESH individual measures, very high levels of perfor-
and a ZESH is the first achieves a significant reduc- mance require the coherent application of mea-
tion in overall energy consumption compared to sures, which together optimise the performance of
standard construction practices with no actual set the complete building system.
energy consumption target, whereas a ZESH The use of design guidelines is one way that
achieves a yearly net-energy consumption of zero. designers try to optimise building performance.
Designing a LESH involves the coupling of many There are various books and articles that give spe-
different systems to achieve an energy efficient cific guidelines on how to design energy efficient
design, which also generates on-site energy using houses following passive solar techniques: (Chiras,
renewable energy technologies. The design 2002, CMHC, 1998, Athienitis and Santamouris,
involves the use of various types of systems, which 2002) to list a few. The difficulty of using design
can vary depending on the specific design objec- guidelines is that they are generally dependent on
tives, the project location, the knowledge of the the climate where they were developed and the
designer, etc., all of which lead to many different specific technologies that were used in their devel-
7

2. opment. Another drawback of using guidelines is EQuilibrium demonstration project. The program
Rémi Charron
that they are generally developed assuming ideal attracted a lot of attention from architects and
conditions. There may be situations where a solar homebuilders from across Canada. A total of 72
house is built on a property that is not directly fac- different teams submitted project proposals to
ing south or that is partially shaded, where existing CMHC to be considered for the demonstration pro-
design guidelines would perform poorly. Design gram. A selection committee then reviewed these
guidelines that aim to help improve cost effective- proposals and selected 20 projects to continue to
ness are also very dependent on the costs of ener- the second phase of the program, the design
gy and relevant technologies. Projected decreases phase, which followed an integrated design process
in the price of PV technologies in the next couple of (IDP) with design charrettes. These 20 teams then
decades (Hoffmann, 2006) will result in changes to submitted their final project proposal including
the configuration of optimal designs. If it becomes detailed designs to CMHC. The committee then
less expensive in the future to install larger PV sys- evaluated all the projects and selected 12 projects
tems as opposed to certain energy efficiency mea- to be built across Canada, which will be finished
sures, it will likely change the recommended construction in late 2007 or early 2008. Once
designs. complete, a monitoring phase will demonstrate the
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
A design tool that would help address these feasibility of building net-zero energy homes in a
issues would integrate optimisation algorithms to range of Canadian geographic and climatic condi-
help designers filter through the countless possible tions.
design solutions to consider only the most promis- Each submitted design was evaluated based
ing options. Coupling optimisation with energy sim- on five guiding principles: Health, Energy,
ulation programs would help account for differ- Resources, Environment, and Affordability (CMHC,
ences in technologies, local climate, economics, 2007). To rate the Energy component of the
and other design constraints to assist the designer. designs, the EnerGuide for Houses (EGH) rating
This article presents different international LESH and methodology was used (NRCan, 2007) with some
ZESH initiatives, along with a discussion of current modifications to reflect to objective of reaching net-
design methodologies and how optimisation tools zero energy consumption. The main modification
could help improve the design process. Given the was to allow participants to justify a modification to
level of activity that is currently occurring related to the baseload energy consumption. For the EGH
low and net-zero energy houses around the world, rating, the baseload energy consumption for appli-
not all programs have been listed. Examples of ances and lighting is assumed to be constant for all
programs that were not mentioned are the LEED designs evaluated at 8,760 kWh per year. This
rating program that now covers different building baseload consumption is not representative of what
types from residential to commercial to neighbour- you would expect in a net-zero energy houses. Of
hood development projects, from new construction the 12 winning designs, the predicted baseload
to renovations (USGBC, 2007). The LEED neigh- energy consumption ranges from assumed values
bourhood rating is a pilot program that provides of 2,734 kWh to 5,450 kWh per year. These con-
principles of smart growth, urbanism, and green sumption values are not modelled and are calcu-
building into the first national US standard for lated based on assumptions of what future home-
neighbourhood design. owners would have in terms of appliances and
lights. In reality, these values would depend on the
energy consuming behaviours of the future occu-
LOW AND NET ZERO ENERGY SOLAR pants. If the houses come with energy efficient
HOMES lighting with occupancy controls and the most ener-
gy efficient appliances, energy consumption will be
EQuilibrium Design Competition reduced; however, secondary plug loads such as
In 2006, Canada Mortgage and Housing entertainment systems can result in a wide range of
Corporation (CMHC) in co-operation with Natural energy consumption levels.
Resources Canada (NRCan) initiated the
8

3. Building America Program of proposed solutions to test and improve their con-
Rémi Charron
The Building America Program was examined in the cept from an energy efficiency and cost perspective
2005 review of solar home initiatives (Charron, with changes being incorporated into the design
2005). Building America's systems-engineering before additional houses are built. This process of
approach unites segments of the building industry analysis, field implementation, re-analysis, and
that have traditionally worked independently of one design alteration facilitates ultimate home perfor-
another by forming five Building America teams mance once a design is ready for use in production
that bring together hundreds of different companies or community-scale housing.
including architects, engineers, builders, equipment
manufacturers, material suppliers, community plan- California Solar Homes Partnership
ners, mortgage lenders, and contractor trades In California, the New Solar Homes Partnership
(Building America, 2007). This industry-led, cost- (NSHP) provides financial incentives and other sup-
shared partnership program has the following five port for installing eligible solar photovoltaic (PV)
broad goals: reduce whole-house energy use by systems on new residential buildings with a goal of
40-70% and reduce construction time and waste; creating a self-sustaining market for solar homes
improve indoor air quality and comfort; integrate where builders incorporate high levels of energy
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
clean onsite power systems; encourage a systems- efficiency and high performing solar systems
engineering approach for design and construction (California Energy Commission, 2007). The NSHP
of new homes; and accelerate the development is part of a comprehensive statewide solar program
and adoption of high-performance residential ener- known as the California Solar Initiative (CSI). The
gy systems. NSHP which seeks to achieve 400 MW of installed
,
The fourth goal is to have the industry rethink solar electric capacity in California by the end of
how homes are designed and built. The teams 2016, will help meet the three goals of the CSI set
design houses from the ground up, considering the out in the Senate Bill 1:
interaction between the building envelope, - to install 3,000 megawatts (MW) of distrib-
mechanical systems, landscaping, neighbouring uted solar PV capacity in California by the end
houses, orientation, climate, and other factors. This of 2016;
approach enables the teams to incorporate energy- - to establish a self-sufficient solar industry in
saving strategies at little or no extra cost. In order which solar energy systems are a viable main-
to accomplish the systems-engineering approach, stream option in 10 years; and
players from the building industry that have tradi- - to place solar energy systems on 50 percent
tionally worked independently, need to work togeth- of new homes in 13 years.
er from the start of a project. Their experience has
shown that energy consumption of new houses can The California Energy Commission will provide
be reduced by as much as 50% with little or no Expected Performance-Based Incentive (EPBI),
impact on the cost of construction. based on the reference system receiving
The design process of these integrated $2.60/watt for production homes with solar as a
Building America teams starts with an analysis and standard feature, or $2.50/watt for other homes.
selection of cost effective strategies for improving The EPBI pays more for affordable housing with
home performance. Next, teams evaluate design, $3.50/watt for individual units and $3.30/watt for
business, and construction practices to identify cost common areas. Note that the incentive amount will
savings. Cost savings can then be reinvested to gradually decline as more PV gets installed through
improve energy performance and product quality. the NSHP program as outlined in the NSHP
For example, a reduction in the heating and cool- Handbook (California Energy Commission, 2007).
ing load of the building can lead to less expensive In addition to the EPBI, additional funding is pro-
heating and cooling systems, with cost savings then vided by the utilities for meeting Tier I and Tier II
reinvested in high-performance windows to further energy efficiency requirements.
reduce energy use and costs. The teams then start To qualify, the residential buildings must
with an initial "test" home with the field application achieve energy efficiency levels substantially greater
9

4. than the requirements of the current state mandat- USA that are aiming to adapt and introduce the
Rémi Charron
ed energy efficiency standards. As mentioned there successful German Passive House Standard,
are two tiers of energy efficiency for the program: renewable energy systems, water management sys-
Tier I - achieves a 15 percent reduction in the resi- tems, innovative Passive House technologies
dential building's combined space heating, cooling, through technology-transfers and engineering and
and water heating energy compared to the current construction of certified Passive Houses into the
standard; and Tier II - calls for a 35 percent reduc- Canadian and US - Housing market.
tion in the residential building's combined space
heating, cooling, and water heating energy and 40 Passive House Certification
percent in the residential building's space cooling. To Passive House standard does not dictate what
In both the Tier I and II, each appliance provided by design process needs to be followed, but instead
the builder must be Energy Star if an Energy Star mandates that strict design guidelines be respected.
designation is applicable for that appliance. The Passive House Institute in Germany has
released the Passive House Planning Package
Passive House Standard (PHPP) to assist in the design. The PHPP is essen-
The 2005 review of solar home initiatives (Charron, tially a series of design tools produced to help
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
2005), presented the Passive House Standard that building architects and designers build houses that
started in Germany and is being introduced in other achieve the Passive House standard. To ensure that
European countries. The Passive House standard the quality is carried through from conception to
was identified as a good example of low energy construction, the Passive House Institute (PHI,
construction that utilizes passive solar techniques in 2007) has a developed a certification process
conjunction with other energy efficiency measures. where buildings are certified as "Quality Approved
To meet the requirements, the house needs to have Passive House" by the Passive House Institute, the
a heating load of less than 15 kWh/m2/yr, and a Passivhaus Dienstleistung GmbH or other persons
combined primary energy consumption of 120 who have been authorized by the Passive House
kWh/m2/yr, including heat, hot water, and house- Institute. These authorised certification agents get
hold electricity consumption. The Passive House involved between preconstruction and final plan-
standard is continuing to be promoted in Europe ning, with a preliminary test for certification that
and other parts of the world through a number of examines relevant points in the proposed design,
organisations and initiatives. construction, building services and energy balances
There is an initiative funded by the Intelligent of the building, and if necessary suggestions for
Energy for Europe SAVE programme, called improvements are worked out. The agents also fol-
Passive-On, that is aiming at developing and intro- low up after construction by testing the air tightness
ducing a Passive House standard for the warm cli- of the building envelope. To date, over 550
mates of southern Europe (Passive-on, 2007). In dwellings, office buildings and public buildings
addition to the Passive-On project, a second pro- have obtained the certification.
ject, Promotion of Passive European Houses (PEP),
is a consortium of European partners, supported by
the European Commission, Directorate General for DESIGN OPTIMISATION APPROACHES
Energy and Transport that has a goal to promote
regional economic activities in order to induce a In North America, there are generally very few peo-
substitution of expenses for energy use during the ple involved in the design of most detached resi-
lifetime of houses with investment in the building dential house projects. In many cases, the owner
envelope (PEP 2007). There are various other ini-
, or developer, and the house designer/draftsperson
tiatives that are underway to disseminate the Passive are the only individuals involved in the design. In
House standard in other parts of the world. Global the highly competitive detached residential market,
Passive House Technologies Inc. is a Canadian very lean production/design teams have evolved.
company (GPHT Inc., 2007) as part of a joint-ven- Another factor that has kept the design costs for
ture between companies from Germany, Austria, detached houses very low is the availability of low
10

5. cost mass-produced plans and plan books. For al., 2003) recommends 25 to 50 people to partic-
Rémi Charron
instance, a quick check on the Internet for residen- ipate in a mini-charrette or full-scale charrette, stat-
tial house plans (eplans, 2007) yielded a full set of ing that less than 25 participants reduces the ben-
plans for a 222 square metre (2387 square foot) efits of the charrette process.
house for $685 US. For this price one would get 5 As can be expected, the costs to conduct a
sets of blueprints, which in many jurisdictions in charrette can vary widely. Paying numerous design
Canada would be sufficient to build a house. professionals to attend multi-day charrettes can be
It is difficult to add innovation in the tradi- an expensive proposition. For the case of the
tional design process of larger commercial or insti- EQuilibirum competition, most professionals
tutional buildings or smaller detached residential attended the charrettes on a pro-bono basis. The
projects, which often depend on a typical trial-and- EQuilibrium format allowed for a lot of exposure to
error design process. In residential projects this is the design professionals and was a great learning
due to the automated design process. It is possible opportunity. For a typical homeowner however, the
to have an automated process with solar through professionals would be paid. Using an IDP with a
the use of ready-made plans with solar, such as the large charrette can lead to much larger design
passive solar home plans that come with CMHC's costs compared to typical design fees for a house.
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
Tap the Sun (CMHC, 1998). However, the perfor- Given that the charrette process was developed
mance of active solar technologies can vary from more for larger commercial or institutional build-
one location to the next depending on orientation, ings, it would be very beneficial to define a process
shading, solar availability, etc., that optimal perfor- that would be geared towards building individual
mance would be achieved only through site specif- low energy houses. Note that builders that are
ic designs developed with the use of simulation developing whole neighbourhoods would still ben-
tools. This section looks at the use of the integrat- efit from having large conventional charrettes.
ed design process for the design of residential
buildings, followed by an introduction to using for- Integration of Formal Optimisation Algorithms to
mal design optimisation to assist with the design Design Process
process. The design of low and net-zero energy buildings
involves the integration of multiple systems that can
Integrated Design Process vary depending on the specific design objectives,
The integrated design process (IDP) has evolved as the project location, the knowledge of the design-
a response to the need to improve the traditional ers, and other factors. The energy use and energy
design process of commercial, institutional, or larg- cost of a building depends on the complex interac-
er residential buildings. Although the merit of using tion of many parameters and variables making the
an IDP has been shown in multiple low energy problem far too complex for "rules of thumb" or
building designs, it is seldom used. It is even more hand calculations. The application of computerised
rarely used in the design of single detached hous- optimisation techniques to the design of low and
es. The Canadian EQuilibrium competition man- net-zero energy buildings would provide architects
dated that all teams needed to follow an IDP The . and engineers with a powerful design tool (Coley
EQuilibrium design charrettes generally had a sub- and Schukat, 2002). This section provides two
stantial number of individuals involved. For example optimisation tools that have been devel-
instance, the Edmonton charrette had approxi- oped to help design low and net-zero energy build-
mately 32 individuals involved over the two-day ings. These types of tools could be a major asset
interval, plus an earlier charrette where more infor- to a designer's toolbox providing assistance in the
mation was gathered. The Saskatchewan charrette development of high performance design alterna-
had 18 individuals present. Compared to standard tives.
housing design practices, this is a lot of participants
in the design process. However, it is not unusual to Results using GA Optimisation Tool
have such high numbers of participants in design In recent years, genetic algorithms (GA) have been
charrettes. NREL's Charrette Handbook (Lindsey, et used to optimise different building systems includ-
11

6. Rémi Charron
Table 1 . Average HDD, CDD and solar radiation for varying cities
ing optimising solar collector and storage tank size of GA in optimising buildings and other engineer-
(Kalogirou, 2004); a low energy community hall ing problems is emerging since it has been shown
including the shape of the perimeter, roof pitch, to have high efficacy in solving complex problems
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
constructional details of the envelope, window for which conventional hill-climbing derivative-
types, locations and shading, and building orienta- based algorithms are likely to be trapped in local
tion (Coley and Schukat, 2002); window size and solutions (Caldas and Norford, 2002).
orientation (Caldas and Norford, 2002); conceptu- This section provides a sampling of the
al design of office buildings (Grierson and results that were obtained using a GA Optimisation
Khajehpour, 2002); HVAC sizing, control, and Tool that linked a TRNSYS energy simulation model
room thermal mass (Wright, et al., 2002) the with a GA program based on code written by
design of an office building in Montreal (Wang, et (Carroll, 2005) in order to find cost-effective low
al., 2005, Wang, et al., 2006); and more. The use and net-zero energy solar home designs. The tool
Table 2 . Resulting optimal configurations with cities of varying climates
12

7. was first presented in (Charron and Athienitis, tored in. The results are summarised in Table 2.
Rémi Charron
2006) and the verification of the models was pre-
sented in (Charron and Athientis, 2007). For a Effects of building and lot characteristics
more detailed description of the tool and for more One typical restriction that occurs with new con-
results, please refer to (Charron, 2007). struction is a building lot that does not face south.
The optimisation tool was used to compare the
Climate Effects of Optimal Configuration base case that faced south in Montreal, versus a lot
The first element examined is how well the tool that faced 45ºSW and one that faced 45ºSE.
could alter the optimal design of a building chang- Overall window areas, solar thermal collector area,
ing only the local climate. In order to see the and roof pitch were the only parameters that varied
impacts of climate on the optimal design configu- from one situation to the other, with the differences
ration, the optimisation was run with climate data summarised in Table 3. As expected, the south-fac-
from one of Canada's coldest cities, Iqaluit, one of ing orientation reached the most favourable results.
its milder cities, Nanaimo, a city with an average The only difference between the optimal configura-
climate, Montreal, and from a hotter US city, tion for the south and the 45ºSE orientation was the
Sacramento. The average climate of the cities is roof slope. For the 45ºSW orientation, the optimal
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
presented in Table 1. The difference in the most window area became smaller on the south façade
optimal design between Montreal and Nanaimo and larger on the east façade. The overall electric-
varied only by the south window coverage and the ity consumption is not very different between the
exterior wall type; Nanaimo required less insulation cases at an increase of only 4.9% and 6.8% for the
in the exterior walls and called for fewer south-fac- SE and SW orientations, respectively. Higher costs
ing windows. It is interesting to note that despite are attributed to the need for more PV panels, and
their very different climates, the overall yearly elec- for the larger roof slope. An increase in the slope
tricity consumption of Nanaimo and Montreal var- from 45.0º to 56.3º is estimated to cost $3,160,
ied by only 12 kWh per year. As expected, the most and results in a less than optimal PV performance.
costly design was for Iqaluit, which had an annual The higher roof slopes called for in the off-south
electricity consumption that was 55.3% more than orientations is a result of requiring more surface
in Montreal. This was not a surprise since it has area to place all the PV and solar thermal collectors
107% more heating degree-days per year. The to reach the net-zero energy target. If roof area
optimal design for Sacramento had a monthly cost considerations were not considered, the optimal
function that was 30.8% lower than in Montreal, slope would be 36.9º for south-facing, 26.6º for
despite an annual electricity consumption that was south-west, and 36.9º for south-east facing orien-
only 7.3% lower. The cost effectiveness of building tations.
net-zero energy homes in Sacramento is better due
to cost savings in other parameters and in the high- Impacts of Declining Costs of Solar Energy
er PV generation per installed kW. These results All of the results, unless otherwise stated, used an
start to explain why more net-zero energy homes assumed cost of 13,52 $/W for the PV system,
have appeared in California than in Canada, espe- which was based on data for the average cost of a
cially if the higher electricity costs and increased complete installed PV system in Canada in 2004. If
government support for solar technologies are fac- the cost data from 2005 had been used, which had
Table 3 . Variation in optimal results with different lot orientations
13

8. an average cost of 11,25 $/W (IEA PVPS, 2006),
Rémi Charron
the optimal configuration might have been impact-
ed for some of the tested scenarios. However, this
was not the case for the base case that had the
same resulting optimal configuration, the only dif-
ference was that the monthly cost function
decreased by 12.4% to $363.52/mth. One can
see that the monthly costs is highly correlated with
the PV cost as a 16.8% drop in PV cost resulted in
12.4% savings in monthly costs for the same opti-
mal design configuration.
The reported installed price of a PV system
dropped by 16.8% in a single year from 2004 to
2005. At this rate of decline, the price would drop
to 7 $/W between 2007 and 2008. At this cost,
the optimal configuration and cost function would Figure 1. Conceptual plot of the path to net-zero
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
change. The optimal collector area drops from 12 energy (Christensen, et al., 2006)
m2 to 9 m2, the tank volume from 681 L to 454 L
results, the most cost-effective combination is
and the wall changes from the SIPS wall of RSI-
selected as an optimal point on the path and put
8.59, to the 0.05 m x 0.15 m (2"x6") wall of RSI-
into a new building description. The process is
5.20. These changes increased electricity con-
repeated based on this new configuration along the
sumption by 9.1%, which increased the required PV
path to net-zero energy.
capacity from 4.8 kW to 5.3 kW, and resulted in a
The BEopt optimisation is looking at the best
decrease in the monthly cost function of almost
ways to save energy. Once the cost of energy sav-
37% to $258. These results show that as the price
ings becomes greater than the cost of electricity
of PV systems decrease that the economic viability
generated with the PV system, the building design is
to achieve the net-zero energy target is improved,
held constant, and the PV capacity is increased to
and they show the importance of keeping costs up-
reach the net-zero energy target. This concept can
to-date in order to find the optimal configuration.
be seen in Figure 1, where after point 3, which rep-
resents approximately 50% energy savings, the
The Use of BEopt to Support Building America
cash flow line is linear until it reaches the net-zero
Program
target, point 4, since only PV is added which
The US National Renewable Energy Laboratory
reduces the utility bills but adds costs to the mort-
(NREL) has developed BEopt that links an optimisa-
gage. One interesting result that has been shown
tion algorithm to building and solar simulation pro-
with BEopt is that significant energy savings can be
grams to help find cost effective ZESH designs
achieved at a lower total monthly cost to the home-
(Christensen, et al., 2005). BEopt uses DOE-2
owner than a base-case house.
simulation program to calculate energy use func-
tions related to the building and TRNSYS for solar
domestic hot water and PV generation. For the
CONCLUSION
optimisation, the tool uses a sequential search tech-
nique to automate the process of identifying opti-
The growing concern in regards to global warming,
mal building designs along the path to net-zero
the continual development of energy-efficient appli-
energy (Christensen, et al., 2004). The sequential-
ances and HVAC systems, the expected drop in PV
search approach involves searching all categories
and solar thermal collector prices, and other driving
(wall type, ceiling type, window glass type, HVAC
factors should lead to the eventual emergence of
type, etc.) for the most cost-effective combination at
solar homes that either consume zero net energy or
each sequential point along the path to net-zero
generate a surplus of energy. Advances in com-
energy (Anderson, et al, 2006). Based on the
puting power and costs have helped facilitate the
14

9. task to design low and net zero energy solar homes. CARROLL D., 2005, FORTRAN Genetic Algorithm (GA)
Rémi Charron
They have helped improve the accuracy and capa- Driver <http://cuaerospace.com/carroll/ga.html> retrieved
bilities of building energy performance simulation on June 1, 2005.
tools and can soon help in the emergence of a dif-
CHARRON, R., 2005, A Review of Low and Net-Zero Energy
ferent type of tool altogether, the building optimisa-
Home Initiatives. NRCan/CETC report <http://cetc
tion tool. In order to help accelerate the uptake of
varennes.nrcan.gc.ca/en/er_re/pvb/p_p.html?2005 133>.
low and net-zero energy solar homes, new design
tools need to emerge that help designers and poli- CHARRON, R., 2007, Development of a Genetic Algorithm
cymakers determine the most cost-effective mix of Optimisation Tool for the Early Stage Design of Low and Net-
technologies that needs to be utilised in order to Zero Energy Solar Homes, Unpublished Ph.D. Thesis,
achieve their design objectives. Concordia University.
CHARRON, R., and ATHIENITIS, A.K., 2006, 'The Use of
ACKNOWLEDGEMENTS Genetic Algorithms for a net-Zero Energy Solar Home Design
Optimisation Tool', 23rd International Conference on Passive
Financial support for this collaborative research Low Energy Architecture, Geneva, Switzerland.
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
project was provided in part by Natural Resources
CHARRON, R., and ATHIENITIS, A.K., 2007, 'Verification of a
Canada (NRCan) through the Technology and
Low Energy Solar Home Model to be Used with a GA
Innovation Program and through scholarship from
Optimisation Tool', Joint SESCI 32nd and SBRN 2nd Annual
the National Science and Engineering Research Conferences, Calgary.
Council of Canada. The author would also like to
acknowledge Dr. Lisa Dignard at NRCan for her CHIRAS D., 2002, The Solar House: Passive Heating and
assistance in reviewing the article. Cooling, Chelsea Green Publishing, Vermont.
CHRISTENSEN, C., HOROWITZ, S., and BARKER, G., 2004,
REFERENCES 'A Sequential Search Technique for Identifying Optimal
Building Designs on the Path to Zero Energy Buildings', ASES
ANDERSON, R., CHRISTENSEN, C., and HOROWITZ, S., Annual Meeting, Portland.
2006, Program Design Analysis using BEopt Building Energy
Optimisation Software: Defining a Technology Pathway CHRISTENSEN, C., HOROWITZ, S., GIVLER, T., and BARK-
Leading to New Homes with Zero Peak Cooling Demand, ER, G., 2005, 'BEopt: Software for Identifying Optimal
ACEEE 2006 Summer Study Pacific Grove, California, Building Designs on the Path to Zero Net Energy', ISES Solar
NREL/CP-550-39827. World Congress 2005, Orlando.
CMHC, 1998, Tap the Sun: Passive Solar Techniques and
ATHIENITIS, A.K., and SANTAMOURIS, M., 2002, Thermal
Home Designs, CMHC, Canada.
Analysis and Design of Passive Solar Buildings, James and
James, London, UK.
CMHC, 2007, CMHC EQuilibrium Housing Website
<www.cmhc schl.gc.ca/en/inpr/su/eqho/index.cfm>
Building America, 2007, US Department of Energy Website
retrieved on December 18, 2007].
<www.buildingamerica.gov> retrieved on December 15,
2007.
COLEY, D., and SCHUKAT, S., 2002, 'Low-energy Design:
Combining Computer-based Optimisation and Human
CALDAS L., and NORFORD, L., 2002, 'A Design
Judgement', Building and Environment, 37, 1241-1247.
Optimisation Tool Based on a Genetic Algorithm',
Automation in Construction, 11, 173-184. Eplans, 2007, ePlans.com Company Website
<www.eplans.com> retrieved on June 30, 2007.
California Energy Commission, 2007, New Solar Homes
Partnership Guidebook, 2nd Edition, CEC-300-2007-008- GPHT Inc., 2007, Global Passive House Technologies Inc.
CMF. Website <www.globalpassivehouse.com> retrieved on
December 20, 2007.
15

10. GRIERSON D.E., and KHAJEHPOUR, S., 2002, 'Method for
Rémi Charron
Conceptual Design Applied to Office Buildings', Journal of
Computing in Civil Engineering, 16, 83-103.
HOFFMANN, W., 2006, 'PV solar electricity industry: Market
growth and perspective', Solar Energy Materials & Solar Cells,
90, 3285-3311.
IEA PVPS, 2006, Trends in Photovoltaic Applications: Survey
report of selected IEA countries between 1992 and 2005.
Report IEA-PVPS T1-15:2006.
KALOGIROU S., 2004, 'Optimisation of Solar Systems Using
Artificial Neural-networks and Genetic Algorithms,' Applied
Energy, 77, 383-405.
LINDSEY, G., TODD, J. A., and HAYTER, S. J., 2003, A
open house international Vol 33, No.3, September 2008 A Review of Design Processes for Low Energy Solar Homes
Handbook for Planning and Conducting Charrettes for High
Performance Projects, NREL Publication NREL/BK-710-
33425, Golden, Colorado.
NRCan, 2007, Office of Energy Efficiency Website
<http://oee.nrcan.gc.ca/english/index.cfm> retrieved on
April 30, 2008.
Passive-On, 2007, Passive-On Project Website.
<http://www.passive-on.org/en/> retrieved on December
14, 2007.
PEP. 2007, Promotion of Passive European Houses Website.
Available from: <http://www.europeanpassivehouses.org/>
retrieved on December 5, 2007.
PHI, 2007, Passive House Institute Website <www.passive-
house.com/index_PHI.html> retrieved on December 11,
2007.
USGBC, 2007, US Green Building Council Website
<www.usgbc.org> retrieved on December 15, 2007.
WANG W., RIVARD, H., and ZMEUREANU, R., 2005, 'An
Object-oriented Framework for Simulation Based Green Author's Addresses
Building Design Optimisation with Genetic Algorithms', Prof. Dr. Rémi Charron
Advanced Engineering Informatics, 19, 5-23. Natural Resources Canada
CANMET Energy Technology Centre - Varennes
WANG, W., RIVARD, H., and ZMEUREANU, R., 2006, 'Floor 1615, Lionel-Boulet, Varennes, Quebec, J3X 1S6,
Shape Optimisation for Green Building Design', Advanced Canada
Engineering Informatics, 20, 363-378. Energy Systems Engineering Technician (ESET) and
Technologist Program
WRIGHT, J., LOOSEMORE, H., and FARMANI, R., 2002, St. Lawrence College
'Optimisation of Building Thermal Design and Control by 100 Portsmouth Ave.
Mutli-criterion Genetic Algorithm', Energy and Buildings, 34, Kingston, ON, K7L 5A6, Canada
959-972. rcharron@sl.on.ca
16