36
building for education project report
Air tightness had to be kept down to 1.0 m2
/hr.m3 –no
mean feat in a building of such size and complexity
‘You need to know exactly what you are going to build because if you repeat an inaccurate detail you could miss out on
Passivhaus certification’ Jonathan Chadwick
repeat an inaccurate detail that would cause you to miss out on Passivhaus certification,” says Chadwick. He adds that the use of BIM software was “vital” to ensure
that all aspects of the design were coordinated without clashes and achieve a level of accuracy that would have been “very difficult using just 2D drawings.” The curtain walling for the three towers was prefabricated
off-site to increase quality and precision. There are approximately 500 brick slip panels in total, each one is storey height and incorporates windows and a concealed blind. An £80,000 large scale mock up of one section of the
curtain wall, was tested to its limits by blasting it with air and water using an old aircraft engine to identify any issues. It was considered important to understand how all the
elements would integrate, including the electrical and data feeds through the airtight layer, and how insulation would integrate with all the airtight seals. The walls for the ground and first floors were constructed
BUILDING PROJECTS
www.architectsdatafile.co.uk
using traditional masonry brick and block cavity walls, filled with 300 mm of cavity insulation. This approach was more time-consuming and placed greater reliance on the quality of individual workmanship, using wet plaster and tape to achieve airtightness. Chadwick adds that getting the details right on site was key:
“Main contractor Willmott Dixon, had to keep on top of what everyone was doing on site to ensure the correct detailing, installation and workmanship was up to scratch.” Sectional air permeability tests of discrete areas of the
building were carried out to check progress. An earlier plan to air-test an entire block, or entire wings of the building, was ditched when the team realised the complexity required to coordinate over 200 people on site to temporarily seal up the structure.
Innovating passive design
The Passivhaus approach requires, counter-intuitively, that a building’s heating requirements are met by ‘actively’ pre-heating fresh incoming air. The Centre of Medicine utilises a state-of-the-art heating, cooling and ventilation system, and 30 per cent of the air entering the building passes through Rehau ‘earth tubes,’ also known as ground air heat exchangers. The earth tubes pre-cool incoming air, in the summer, and pre-heat it in the winter, to enable a consistent comfortable
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108