Some ideas about impact of climate change on building design. And some observations due to roof collapses in December 2010 due to snow. Presented at TC Architects in 2011.

1. Climate change
Impact on the Belgian
building construction
Benoit PARMENTIER
Head Division Structures
BBRI (www.bbri.be)

2. [Climate change – The risks]…
Parry et al (2001)

3. Climatic actions
on the building…
(more) Wind (Elevated) Temperature (more) Rain (more) Snow
New climate New actions

4. Is the climate
really changing ?

5. [Some facts]…

6. [Some facts]…
The Netherlands : [+ 1…+3°C] in 2050
IPCC : [+ 2…+6°C] in 2100

7. [Some facts]…
Average 12
Temperature
[°C]
10
8
6
4
Yearly average temperature
2 increases @Uccle (BE)
0
1820 1970 2020

8. No increase of cold weather
periods

9. No increase of rain

10. (min 20mm / day)
No rain increase
(max in 1h)

11. [Some facts]…
No storms increase
(Vmax>70km/h)

12. [Some facts]…
Number of tornadoes stable
12
10
8
6
4
2
0
1982 2010
Waregem (2005)

13. [Some facts]…
Snow days (even) decreasing !

14. Is it important ?

15. What do you think ?

16. Roissy-T2E (2004, 5 deaths)
This is partly due to thermal effects…

17. Redundancy vs. Design …on the edge
Samyn & Partners

18. Adaptation strategies (3)
1. Do nothing
2. Standards adaptation
(today scenarii ?)
3. Progressive adaptation
Steenbergen et al (2009)

19. [Recap]…
Belgian climate evolution
(apart from elevated
temperatures) is rather
limited
Impact of climate change
on building construction is
uncertain, but can be
important

20. Flat roofs collapse
Some insights about
December 2010 in Belgium

21. [Context]…
Newspaper articles 10
about roof collapses 0
01/12/10 31/12/10

22. [Context]…
Geographical distribution
of the accidents

23. [Context]…
+40 Collapses in
Belgium in 2010

24. Light structures
(steeldeck, timber,…)

25. Large flat roofs

26. 1. Exceptional snow ?
2. Snow nominal density ?
3. Design methods ?
4. Accumulations ?
5. Others…?

27. 1. Exceptional snow ?

28. Flashback…
Papers related to roof
collapses in Belgium
2010-2011
2005-2006
2000 2006 2011

29. Abnormal cold
temperatures
20°
15°
5°
0°
-5°
-15°
December 2010

30. Height Accidents
[cm] 35 7
Snow+Rain
30 6
25 5
20 4
15 3
Snow
10 2
5 1
0 0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
December 2010 @Uccle

31. Max. Snow Design
level [m]
0.8
0.7
0.6
0.5
0.4
32cm
0.3
0.2
Observation
0.1
0.0
0 100 200 300 400 500 600 700
Altitude [m]

32. 2. Snow nominal density ?

33. [Density variation]
Snow
γsnow [kN/m³]
Fresh 1,0
1,5 Belgian standard (design)
Some days 2,0
Some weeks 2,5 à 3,5
Wet 4,0

34. 3. Design methods ?

35. [Design methods]
Eurocode 1 Part 1-3
(NBN EN 1991-1-3)

36. 4. Accumulations ?

37. Dynamic effects

38. 5. Others…?

39. [Ponding effect]
Ponding effect

40. [Ponding effect]…

41. Where do the rain go ?

42. [Ponding effect]…
Design gargoyles (b)
b

43. Roof slope evolution ifo the
water level
Initial roof
slope
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15
Wijte (2005)

44. 1 m³
Assume dysfunctioning
common water discharges…
0.35
0.25
0.15
Water level
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

45. 2 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

46. 3 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

47. 4 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

48. 5 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

49. 6 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

50. 7 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

51. 8 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

52. 9 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

53. 10 m³
0.35
0.25
0.15
0.05
-0.05 1 3 5 7 9 11 13 15 17 19 21
-0.15

54. Water level [m]
Peak for designing gargoyles
0.12
0.1
0.08
0.06
0.04
0.02
0
0 2 4 6 8 10
Water volume [m³]

55. [Standardization]
 §5.2 (6) Dans les régions où des pluies sur la
neige peuvent provoquer des fontes suivies de
gel, il convient d’augmenter les charges de neige
sur les toitures, en particulier si la neige et la
glace peuvent bloquer le système de drainage de
la toiture.
 ― NBN EN 1991-1-3

56. [Standardization]
 §5.2 (6) :

― NBN EN 1991-1-3 - ANB

57. [Communication]…
Roof concept
Architect <> Engineer <> Contractor Execution

58. [Credits]
#2 http://fr.wikinoticia.com/culture-science/écologie et environnement
#4 http://klimaforum10.com
#5 http://www.catnat.net/donneesstats
#16 CTK
#17 Samyn & Partners
#20 http://www.photo-depot.com
#25 http://www.tendanceouest.com
#9 Magritte
#37 Régie de bâtiments (thanks to P. Vandenbossche)
#39 CSTC-WTCB NIT 191
#40 S. Wijte
### http://www.meteo.be (thanks to M. Van Diepenbeeck)