BB 101 and BB 93 Birmingham, UK

More about BB101

Building Bulletin 101 also known as BB101 provides the regulatory framework in support of the Building Regulations for the adequate provision of ventilation in schools. It deals with the design of school buildings to meet the ventilation requirements of both the School Premises Regulations and the Building Regulations Part 'F'. This Building Bulletin is quoted in approved documents 'F' and 'L2' (amended 2006) as means of compliance with Regulations 'F1' and Part 'L' of the Building Regulations for school buildings.

Naturalvent can assist our customers in achieving the guidelines set in BB101 by supplying Naturalvent insulated dampers and roof turrets. BB101 states the maximum concentration of C02 should not exceed 5000 ppm during the teaching day. This can be controlled using Naturalvent insulated wall dampers and roof turrets and a Naturalvent Controls Package. BB101 also stated "there should be no more than 120 hours when air temperature in the classroom rises above 28°C". Naturalvent can check this by running a thermal model and then advising how many and where to install insulated dampers and roof turrets.

More about BB93

This section clarifies the guidance for acoustic performance in Building Bulletin 93 (BB93) 4. Naturally ventilated schools are required to meet the standards defined by BB93. Since the publication of BB93, interim guidance for meeting the indoor ambient noise levels at specified ventilation rates was available at www.teachernet.gov.uk/acoustics; this is now superseded and the definitive guidance is as follows:

For the Minimum Fresh Air Supply Rate of 3 I/s per person, the design should achieve the performance standards for the indoor ambient noise levels in Table 1.1 of Building Bulletin 93. If the design uses a Minimum Fresh Air Supply Rate that is greater than 3 I/s per person, the indoor ambient noise levels with this ventilation rate should still achieve the BB93 5.

When the Design Capability Supply Rate of 8 I/s per person is provided by natural ventilation, the design should achieve the BB93 performance standards for the indoor ambient noise levels in Table 1.1 of BB93 when they have been increased by 5 dB L Aeq,30min.

For classrooms designed specifically for use by hearing impaired students and for speech therapy sessions the performance standards in Table 1.1 of BB93 should be met at both ventilation rates.

All mechanical ventilation systems must meet the indoor ambient noise levels in Table 1.1 of BB93.

This means that a natural-ventilation strategy meeting the BB93 ambient noise level requirements should be possible because there is flexibility for lower noise levels during occupied periods at a ventilation rate of 3 I/s per person and higher permissible levels at a higher ventilation rate of 8 I/s per person. In addition, but at the discretion of the teacher, when the classroom is occupied higher noise levels may be acceptable when higher rates of ventilation than 8 I/S per person are required - for example during overheating on hot summer days when it may be necessary to open all the windows.