What is the Priority School Building Programme and design requirements?

The Priority School Building Programme (PSBP) is a centrally managed programme set up to address the needs of the schools most in need of urgent repair. Through the programme, 261 schools will be rebuilt or have their condition needs met by the Education Funding Agency (EFA). All schools within the programme will be delivered by the end of 2017. In May 2014, the Government announced a further phase of school development, known as PSBP2, which is a five-year programme operating between 2015 to 2021 and will undertake major rebuilding and refurbishment projects in schools and sixth form colleges in the very worst condition.

The Facility Output Specification forms the basis for the design of the PSBP Schools and has become the definitive guide to school design. The performance standards stipulated in PSBP requires three criteria, taken together, to be used to assess the risk of overheating of the building in the UK, using the geographically closest CIBSE Design Summer Year (DSY) weather file. A room or building that fails any two of the three criteria is classed as overheating:

· Criteria 1- Hours of Exceedance: During the occupied hours of the non-heating season (1st May to 30th September), the predicted operative temperature should not exceed the maximum adaptive temperature by 1°K or more, for less than 40 hours;

· Criteria 2- Daily Weighted Exceedance: For the severity of overheating, which can be as important as its frequency, the weighted exceedance of the temperature rise and its duration should be less than or equal to 6 during any occupied day of the non-heating season;

· Criteria 3- Upper Limit Temperature: The absolute maximum daily operative temperature for a room, beyond which the level of overheating is unacceptable, should not be greater than or equal to 4°K, than the maximum adaptive temperature (Top – Tmax), at any time.

With regards to internal air quality, TM52 criteria specifies that for natural ventilation or hybrid systems operating in natural mode:

· In all teaching and learning spaces when measured at seated head height, during the continuous period between the start and finish of teaching on any day, the average CO2 concentration of carbon dioxide should not exceed 1500 ppm.

· The maximum CO2 concentration should not exceed 2000 parts per million (ppm) for more than 20 minutes each day.

For mechanical ventilation or hybrid systems operating in mechanical mode, TM52 criteria specifies that:

· In all teaching and learning spaces when measured at seated head height, during the continuous period between the start and finish of teaching on any day, the average CO2 concentration of carbon dioxide should not exceed 1000 ppm;

· The maximum CO2 concentration should not exceed 1500 parts per million (ppm) for more than 20 minutes each day;

In addition to the mechanical and natural ventilation:

· At any occupied time, including teaching periods, the occupants should have the ability to lower the concentration of CO2 to 1000 ppm;

· The extreme maximum CO2 concentration of carbon dioxide should not exceed 5000 ppm during the teaching day.