Blake Lapthorn solicitors' Constuction team held a breakfast seminar on building with hemp on 28 February 2013.

1. You don’t have to be a hippy
to build with hemp!
Ian Pritchett

2. Contents
• Overview of Lime Technology Group
• Background to Tradical® Hemcrete®
• Hemclad® & Hembuild®
• Thermal performance
• Unique funding model

3. Questions
• Which is lower cost?
– £5,000
– £100 per week
• What is the difference between cost and
value?
• What make people choose – cost or value?
• Who drives a BMW?
24 February 2013 www.limetechnology.co.uk 3

4. Lime Technology Group
• Lime Technology Ltd. - manufacturers and
suppliers of breathable construction products:
– Lime mortars, plasters & renders
– Insulation products
• Hemp Technology Ltd. – largest hemp
processing factory in Europe
• Hemcrete Projects Ltd. – specialist “design &
build” sub-contractor

5. Joseph Chamberlain College
Limetec® Mortar

6. CTRL Terminal, St Pancras
Limetec® Mortar

7. Industrial Hemp
Seed
Shiv or Hurd Fibre
s
7

8. Hemp Harvesting in UK

9. Hemp Drying

10. Hemp Baling

11. Hemp Processing (Suffolk)

12. Fuel Briquettes (from waste)

13. Breathe® Insulation (from fibre)
•

14. BMW – Door Panels (from fibre)

15. Lotus Eco-Elise body shell
(from fibre)

16. Hemp Shiv (woody core of stem)

17. Tradical® Hemp Binder (HB)
Production (Oxfordshire)

18. Tradical® Hemcrete®

19. New Technology
From Hemcrete® to Hembuild®
• Traditionally Tradical® Hemcrete® was cast or
sprayed in a wet site process
– 6 to 8 week drying period (in good conditions)
– Best suited to use between March and July
• Now you can get all the benefits of Tradical®
Hemcrete® in an off-site panelised system that is
dried before it gets to site
– Hemclad® and Hembuild® panels
– No seasonal/weather restrictions

20. Hembuild®

21. U-values & Y-values
• 5 standard U-values
– 0.19 W/m2.K
– 0.17 W/m2.K
– 0.15 W/m2.K
– 0.13 W/m2.K
– 0.11 W/m2.K
Excellent Y-values
Typically 0.02 to 0.04

22. Benefits
• Grown and manufactured locally
• From renewable/abundant sources
• Lock up carbon
• Thermal stability from insulation and
thermal inertia
• Fire resistance
• Warranties and accreditations

23. Embodied Carbon
100
80
60
40
Cavity wall
20 Clay block
0 Hemcrete
-20
-40
Embodied
Carbon

24. Affordable Housing

25. Affordable Housing

26. Private Houses

27. Private Houses

28. Hemcrete® Buildings

29. Hemcrete® Buildings

30. Hembuild® & Hemclad®
• Bespoke Panels
• Designed to fit your building
• Designed by our engineers
– To accommodate vertical loads
– To accommodate wind loads
• In plane (racking)
• Out of plane (bending)
• Can be used with primary structural frame
– Hemclad®
• Can be used without a primary frame for low rise
buildings
– Hembuild®

31. Hemclad® - M&S Cheshire Oaks
• 4 year lead in
• Design support to client team
• Manufacture of 2600m2 of Hemclad®
panels
• Site erection of Hemclad® panels
• 100% FSC chain of custody
• U-value of 0.12W/m2.K

32. Hemclad® - M&S Cheshire Oaks

33. Hemclad® - M&S Cheshire Oaks

34. Hemclad® - M&S Cheshire Oaks

35. Hemclad® - M&S Cheshire Oaks

36. Hemclad® - M&S Cheshire Oaks

37. Hemclad® - M&S Cheshire Oaks

38. Hemclad® - M&S Cheshire Oaks

39. Hembuild® - Passiv Haus
• Brick (& lime mortar) faced private house
• Passive Haus specification
• U-values
– Walls – 0.11W/m2.K
– Roof – 0.1 W/m2.K
– Minimal thermal bridging
• Air-tightness – 0.6 air changes per hour
• Built using Hembuild® system

40. Hembuild® - Passiv Haus

41. Hembuild® - Passiv Haus

42. Hembuild® - Passiv Haus

43. Hembuild® - Passiv Haus

44. Hembuild® - Passiv Haus

45. Hembuild® - Passiv Haus

46. 30 year costs

47. 60 year costs

48. Hempod- 200mm thick walls

49. Standard Cast
on-site Wall
System

50. Thermal damping
~80% for 200mm thickness

51. Humidity control
~95% for 200mm thickness

52. Science Museum Archive
• Putting theory into practice
– Based on Bath University test data
• 10,000 Sq ft, 3-storey archive
– Sits within a WWII concrete aircraft hangar
– Steel frame (10KN floor loading)
– CLT floors (160mm & 100mm roof slab)
– Hemclad® walls (200mm)
– 40mm wood fibre board cladding
• Using the Hemcrete® to passively control
temperature & humidity

53. Cast panels – 200mm thick

54. The hangar

55. Cross Section

56. Completed Archive
Photo courtesy of Jennie Hills/Science Museum, London

57. Thermal modelling
• Used external measured weather data from the
site and the building geometry to create an IES
simulation of the Hempod
• Ran IES model of the SIMULATED performance
of the Hempod
• Exported results into a Fourier format
• In parallel we created a Fourier model of
MEASURED internal temperatures in Hempod
(test building)

58. Thermal modelling

59. Thermal modelling
• Created a mathematical relationship between
Fourier models of IES SIMULATED and
MEASURED internal temperatures in the
Hempod and obtained a Fourier “filter”
• Built and run IES model of the Science Museum
Archive
• Applied the (same) Fourier filter to the internal
temperatures obtained from IES SIMULATION
to obtain best PREDICTED performance

60. Fourier filter applied to IES simulated temperature (by Dr L. Jankovic, Emission Zero R&D)

61. Fourier filter applied to IES simulated relative humidity (by Dr L. Jankovic, Emission Zero R&D)

62. M&E System Spec.
• Air handling unit system reduced from
30KW to 5KW peak load
• 2KW average load
• Power from PV array
• M&E cost reduced by 75%
• Reduced on-going maintenance costs
• Cheaper than a block-work archive!

63. On-going Monitoring

64. Thermal Performance
• Tradical® Hemcrete® exhibits a dynamic
thermal performance that greatly exceeds
that predicted in conventional thermal
modelling software (IES)
• Quantifying this performance shows that it
is a cost effective building material
• This is currently an experimental
approach, but it is backed up by real
monitoring data on nearly 40 buildings

65. Future Thermal Modelling

66. Future Thermal Modelling

67. Future Thermal Modelling

68. Cost Efficiency
• Modelling shows heating system can be
reduced from 17KW to 4KW (peak)
• Saving on heating system off-sets the
extra cost of the Hembuild® walls
• Cost neutral on construction
– Lower running costs
– Lower maintenance costs
– Lower CO2 emissions
• True sustainability!

69. A Unique Team
• Lime Technology Group
• Amalgamated Capital
• Mark Hines Architects
• The Green Organisation

70. What we offer…
• Fully funded projects
– 30 year commercial bonds
– Retention of appreciating assets
• Innovative building system – Hembuild®
– Exemplary thermal performance
– Local manufacture & local jobs
– Natural materials - hemp & timber
• Contemporary design & master-planning

71. AmCap USP’s
• Bond is provided up-front to finance the delivery
of the whole project
• Bond is based on income potential of the houses
• Bond interest rolled up during construction
period
• Debt sits off the RP’s balance sheet
• Asset reverts back to RP after 30 years
• The ideal balance between ease, cost and
value!

72. Summary
• Fully funded projects
– 30 year commercial bonds
– Retention of appreciating assets
• Local manufacture
– Local jobs
– Natural materials - hemp & timber
• Contemporary design & master-planning
• Exemplary thermal performance

73. The best way to
predict the future
is to create it