The prep room is the heart of science teaching. A well organised, resourced and suitably sized space will create a positive working atmosphere for technicians and will support the teaching of science.

CLEAPSS* ( recommends that a prep room should be large and well ventilated. Prep rooms should have at least 5 room air changes per hour, which requires that they should have windows that can be opened sufficiently wide and/or forced ventilation (preferred), particularly if chemicals are also stored in them.

Most chemicals should be stored in a secure, internal chemicals store, opening off the prep room itself. A fume cupboard and dispensing area should be nearby.

Gratnells believes that prep rooms should be kept tidy and uncluttered and organised. There should be a range of adjustable tray storage along with open shelves for large items and glassware. The science equipment should be close to hand and easily transferable from tray racking to trolleys and the laboratories. It is a false economy to use unsuitable or poor storage as damage often occurs. With the average value of science equipment in a secondary school at more than £30,000 it is important that part of the science budget should be set aside for looking after it.

CLEAPSS strongly recommends that prep rooms contain a telephone and a computer with a CD-ROM drive (essential to access health and safety information). CLEAPSS now recognise there are pros and cons about being connected to a network. A prep room should not be used as an office area for teaching staff to prepare lessons or marking. Even if it is, provision should be made for segregating the areas. Technicians will, for example, be handling chemicals in bulk or engaged in micro-biological procedures, both of which require the utmost concentration and no interruptions.

* CLEAPSS Technicians and their jobs L228 December 2002

How large should a prep room be?

The Department for Education and Skills * recommends a total area of prep room(s) + storage of 0.4-0.5 m2 per pupil workplace. The upper end of the range may be needed where there are post-16 students to help store additional or more bulky resources. Where laboratories are spread out or on two floors this figure may need to be increased to allow for the duplication of some resources.

For example – for six laboratories each holding 30 students 90m2 is required.

If prep rooms are too small or badly located more storage has to be found in the laboratories or in smaller satellite or ancillary rooms. This leads to dirty or soiled equipment being left in the labs, an increased risk of pupils stealing equipment/materials, and the imposition of even greater restrictions if a room has to be used as a form base or by non-science teachers.

* DfES Building Bulletin 80 (revised 2004), Science Accommodation in Secondary Schools.

How should architects plan the arrangement of prep rooms?

The DfES has identified four main plan types: linear, grouped around a prep room, grouped around a central open space, and linear on two floors.

Linear Plan
refurb linear plan

This arrangement is suitable for schools with up to six laboratories where they are close together. If there are seven or more labs the distance from the prep room can start to become inconvenient. The main advantage of this plan type is that movement between the labs and prep room is easy because the laboratories are on two sides of the corridor.

Grouped around a central prep room
refurb central prep room

This plan is most suitable for schools with more than seven laboratories. Technicians can easily and quickly reach the laboratories. The downside is lack of windows and on a ground floor there can be no natural light.

Grouped around a central open space
refurb central court

This plan provides maximum light and view for technicians. It also provides a secure central area for a greenhouse or environmental area. However, it is less compact than the others as it is not possible to cross the courtyard in normal working conditions.

Linear plan on two floors
linear plan on two floors

This option shares the advantages of the linear plan and in a larger school makes the lab suite more compact. However, it does rely on a good lift for transporting heavy pieces of equipment such as gas cylinders and trolleys. A hoist between the two prep rooms can also work. With two prep rooms there may be some duplication of equipment.

* CLEAPSS Designing and Planning Laboratories L14 March 2000

It should be noted that CLEAPSS prefers a central prep room servicing all three sciences on the same floor. This means that, in large schools, the technicians can work as a team, security will be improved and the prep room can be continuously staffed.

See also, “Designing the Prep Room” on the Laboratory Design for Teaching and Learning project website:, under Documents on the first page menu.