Rob Marsh presents years of research on the Modern History of Passive Solar Architecture: The Nordic Paradox

1. On the Modern History of Passive Solar Architecture:
exploring the paradox of Nordic environmental design
5th Active House Symposium | Bornholm September 2017 | Rob Marsh
1
Rob Marsh
 Architect MAA PhD, Head of Sustainability, C.F. Møller Architects
 Previously Senior Researcher at Danish Building Research Institute
 How can architects integrate sustainability early in the design process

2. On the Modern History of Passive Solar Architecture:
exploring the paradox of Nordic environmental design
• The Nordic Countries have greatly reduced
building energy consumption since the 1970’s
• Resulted in problematic environmental side effects
that were not understood at the time
• How could design solutions be adopted,
which had the opposite effect to those intended?
• Need to learn from the recent past
• Need to understand how environmental paradigms
influence architectural design today
• Need to avoid comparable problems in the future

3. Architecture and Energy in Recent History
1945-1975:
Boundless Growth &
Architectural Optimism
• Interplay between Welfare
State and Functional
Modernism
• Coordinated regulations in
DK, SE and NO
• Low levels of insulation
with no æsthetic impact
1975-1985:
Energy Crisis &
Fabric Loss Paradigm
• Greater thermal insulation in
all walls, roofs and floors
• Double glazing with window
area not greater than 15% of
floor area
• Closed and inward-looking
architecture
1985-2005:
Passive Solar Architecture &
Space Heating Paradigm
• Calculation tools rewarded use
of passive solar energy to
minimise space heating
• Broad support from the
architectrual profession
• Modernist visions of plenty of
daylight
2005-2020:
Broader Approaches &
Environmental Paradigm
• EU – Energy Performance of
Buildings Directive
• Performance-based approach
• Primary energy consumption
for building operation

4. Passive Solar Architecture: Empirical Analysis
• 1985-2005 Space heating paradigm
• Demonstration projects designed
by leading architects
• Extensive monitoring &
documentation

5. 1994: Solar Terraces, Vonsild, Denmark
• Glazing = 30% of floor area
• 85% orientated to the south
• 50% reduction in space heating demand
• Summer temperatures continuously
between 25-33 OC
• Portable air conditioning used
• Most residents moved out
within two years
• Current residents experience
temperatures up to 45 OC

6. 1994: Snekkastua, Hamar, Norway
• Glazing = 25% of floor area
• 75% orientated to the south
• 50% reduction in space heating demand
• Temperatures up to 35 OC during
monitoring in the spring
• Not possible to ventilate naturally
• Mechanical ventilation used
to remove excess heat

7. 2001: Lindås, Gothenburg, Sweden
• Glazing = 15% of floor area
• 80% orientated to the south
• 60% reduction in space heating demand
• Average temperatures over 25 OC
during the summer
• Maximum teperatures of 30 OC
• Rooms too dark on north side
because of small windows

8. 2001: Villa Yxhult, Bo10, Malmø, Sweden
• Glazing = 35% of floor area
• 65% orientated to the south;
20% orientated to the east and west
• No reduction in space heating achieved
• Average temperatures over 25/27 OC
on ground/first floor during the summer
• Maximum temperatures of 29/35 OC
on ground/first floor
• 20% of the year with temperatures
constantly over 26 OC

9. Passive Solar Architecture: Theoretical Analysis
Terrace house with three glazing variations:
• Evenly distributed
• Passive solar
• Extreme passive solar
Two scenarios for 1985 regulations in Denmark
• Typical
• Extra insulation & MVHR
Two paradigms for assessment
• 1985-2005 Space heating paradigm
• 2005-2020 environmental paradigm (EPBD)

10. Passive Solar: 1985-2005 Space Heating Paradigm
• Extreme passive solar gives large
reductions in space heating demand
of between 15-30%
• Reflects realities of calculation and
regulation at the time

11. Passive Solar: 2005-2020 Environmental Paradigm
• Extreme passive solar increases total
primary energy consumption by 10-20%
• Extreme passive solar creates overheating
with temperatures over 25 OC for 15-20%
of the year
• Reflects realities of those living in passive
solar housing

12. The Paradox of Passive Solar
• Diametrically opposite effects in
relation to intended aims
• Space heating paradigm as engineering
dominated regulative straightjacket
• Overheating rationalized away
as technological solution not working
• Passive solar af functionalist ideal
• Roots back to Corbusier’s Five Points
for a New Architecture
• Combined visual, æsthetic and
functional expression of environmental
goals

13. The Heat of the Sun or the Light of the Day?
• NO discussion of daylighting in any of
the passive solar projects!
• Passive solar equals too much daylight
to the south, and too little to the north
• Architectural and functional advantages
from daylighting design
• Studio typology with north-lit spaces
• Sunlight to illuminate the view outside,
not to create distraction in the interior
itself

14. Studio House: Daylighting Design as Driver
• Studio House with
minimum daylight factor of 2.0% and
70% of the glazing to the north and
automatic external shading
• Plus passive and active design solutions
• Overheating eliminated and low primary
energy achieving 2015 low-energy class
• Diametrically opposite design strategy

15. Conclusions
• Passive solar has no role to play in the Nordic and similar climates
• Daylighting design as driver for sustainable and functional architecture
• Avoid regulative paradigms becoming straightjackets and setting design boundaries
• Maintain critical distance to calculation tools and their limitations
• Architect’s holistic overview vs. traditional engineering focus
• Are these patterns being repeated?
• Operational vs embodied energy
• Daylighting vs thermal comfort