ACCON UK Limited (ACCON) was commissioned to
carry out the Acoustics Assessments for the final
design (RIBA Stage 4) for a new maths block at Sir
Joseph Williamson’s Mathematical School,
Rochester, Kent.
The first task for ACCON was to confirm the sound
insulation performance standards required between
classrooms and other rooms so that proposed
partition and floor constructions would meet the
requirements of Building Bulletin 93 (BB93) Acoustic
design of schools: Performance standards. Another
early task was to assess the airborne and impact
sound insulation of the proposed separating floor
construction. Confirmation was needed as to whether
the BB93 performance criteria could be met because
the need for a thicker concrete deck would require
modifications to other parts of the design in relation
to structural loading. ACCON were able to confirm the
BB93 sound insulation values could be met as long
as a resilient vinyl floor or carpet was fitted to the
floor.
The new maths block had received planning
permission and ACCON was required to determine
the impact of noise from the proposed mechanical
ventilation systems on nearby residents in order to
satisfy a planning condition. A detailed noise model
was built using CadnaA for this purpose. An
assessment of the noise levels from the ventilation
systems was also required to ensure that the BB93
internal noise level criteria would be met. The
selected ventilation units were marketed specifically
for use in schools and the ACCON assessment
confirmed the suitability of the system as designed.
The final stage of work involved detailed airborne and
sound insulation assessments to confirm that the
architect’s selected partition details would meet the
BB93 requirements. These calculations took account
of the room layout plans and the sound reduction
index (Rw) data for each partition type. In addition,
reverberation time predictions were carried out based
on the proposed ceilings and other room finishes.
ACCON were able to confirm that with the ceiling tiles
proposed by the architect the reverberation times in
teaching spaces would be within the optimum range
and meet the BB93 performance requirements.
Visit the ACCON UK Ltd website for more information on Sir Joseph Williamson’s Mathematical School