The 2011 airtightness test
The UEA is leading a European Project, Build with CaRe, to help build capacity to produce low-energy buildings. While the team was exploring the history of Elizabeth Fry and subsequent Termodeck buildings on the UEA campus, it was decided that BSRIA would carry out a third pressure test to find out whether the building had become less airtight over time. This was performed on 18 September 2011, nearly 14 years after the PROBE test.
The test results need to be considered in the context of the building's current use. Since 1998, the uses of some internal areas have changed. The staff and student common rooms on the first and second floors have been converted to offices and seminar rooms. In 2008, the kitchen and dining area on the top floor was converted into a densely-occupied, open plan, post-graduate administrative office. As a consequence the kitchen plant was removed and the extract sealed off.
In summer 2011 the ground floor seminar rooms and their blockwork walls were stripped out to provide an administration centre serving a large number of faculties.
Pressure test results
Much to everyone's surprise, the 2011 test revealed the Elizabeth Fry Building to be more airtight than it was in 1998, achieving 5.32 m3/(h.m2) at 50 Pa.
The degradation of door and window seals, plus the deterioration of mastic seals between window frames and the blockwork, might reasonably have led to a higher air leakage rate. But little air leakage was detected. The mastic compriband seals between the cills and the blockwork had fallen apart and this had led to detectable air leakage.
BSRIA believes that the removal of the rooftop kitchen extract plant will have cut out a significant source of leakage. There is also a suspicion that ground floor lecture room ventilation plant may also not have been sealed off in 1998 as effectively as it was in 2011. In 1998, the temporary sealing of the air handling plant relied on the dampers, whereas in 2011 it was sealed with polythene and tape.
The accuracy of the airtightness of the building may be affected by some uncertainty in the envelope area calculations, as these are dependant on the accuracy of the drawings supplied.