Pool Plant Room

I. A Vital Element in The Pool Planning Process

The small area that is required to house the quite small bits of equipment needed for a modern private domestic pool is often neglected in the pool planning process.

This page describes the equipment, the space required and the different options available for the home owner. It will apply to the very smallest pools up to those as large as 12 x 6 metres.

As soon as there is any public use element then the space required can increase rapidly because of the much more stringent sanitation and filtration requirements.


Water sanitation is normally provided by automatic liquid chlorine injection or salt water chlorination control systems. The equipment for both includes the water treatment cells that need to be fixed to a vertical surface, a 25 litre acid container and a 25 litre chlorine container for liquid chlorine injection.


The filtration system elements consist of a floor mounted water circulation pump and a sand filter that is normally 600mm in diameter or more with a side mounted multiport valve. The pool pipework will normally emerge from the floor and be connected into a manifold, the pump, the filter and the water treatment cells.


A programmable time switch and transformers for the pool submerged lights are also normally fixed to a vertical wall in one control unit installed in the pool plant room.


Pool heating does not affect the pool plant room requirements because heat pumps are installed on their own plinth outside the plant room and solar panels will be also installed somewhere outside of course.

All the equipment normally requires about 3 square metres of floor space with the wall behind the space.

It is preferable to keep the pool plant room less than 6 metres from the pool to keep down head loss in the various pipes. The plant room can be above or below the pool water level. If it is below the pool water level an isolation valve is needed to stop the pool from flooding the plant room when essential maintenance is being undertaken.

The pool plant always incorporates 240 volt electrics and so unless the electrical equipment is designed for external use, a waterproof cover must be provided.

II. Pool Plant Room Options

These are:

The timber shed will have a limited life unless it is made in hardwood and it will then be so costly that a concrete block building may be preferable.

The buried PVC box is very inflexible and not really suitable for automatic chlorination because of the access difficulty with dangerous chemicals.

Prefabricated Timber Buildings:

Economical prefabricated timber buildings for the pool plant room are often available from local suppliers – look out for special offers.

Concrete Block Buildings:

Alternatively a concrete block building with a single slope roof should cost in the order of £2000 + and provide enough room for the pool plant as well as your deck chairs etc. The plant room can be used to store all your poolside furniture in winter and /or changing and shower room facilities. If the pool is near an existing garage or barn the pool plant can go in there (about 2 square metres of floor space is required for the pool plant and filtration system).

Buried PVC Plant Housing:

Another alternative is to bury the plant underground in PVC box that looks like this. They have green PVC hinged lids for access.

pvc pool plant housing

Pool installers do not like them much because of the slightly difficult access to the pool filtration components but they do work well. Just make absolutely sure that the pool installer does not drill holes in the box that might let in water.

Believe this can and does happen!

They have the other drawback that if any of the plumbing connections leak, the plant housing can fill with water and cause the electrics to short out.

If the land where the pool is to be built has quite a cross slope then a below ground plant room, built in concrete blocks, is sometimes possible. Costs will vary but are unlikely to be less than £3000.