The efficiency checklist

When specifying heating systems, housebuilders need to take a variety of considerations into account to ensure that they can produce maximum efficiency returns from developments. Bill Jones of Potterton advises on best practice.

The integration of an appropriate heating system into a new build is vital in order to maximise the level of heat output and efficiency for the homeowner. Equipment selection and system design are the first steps to achieving a high performance, efficient heating system.

As well as achieving an appropriate SAP rating, the heating and hot water systems need to perform well in the real world. It is important to take advice from SAP assessors and technical parties, or work with a manufacturer that does so, in order to meet carbon and/or energy targets. Reviewing and adjusting heating and plumbing design plans, as necessary, is vital in ensuring that the final system is the most suitable for the property.


A high quality, efficient boiler can make a massive difference to a property’s SAP rating. SAP ratings are key when choosing a boiler, as is the flow rate, size, weight, and ease of installation. A system compact enough to fit in a standard kitchen cupboard for example, will give installers more flexibility when siting the boiler, making it a perfect solution for those living in multigenerational homes where space is precious. Also, a larger output boiler can allow the system to be used in homes with more than one bathroom.


Although most housebuilders usually have an idea of where the boiler or cylinder needs to be sited, this can change depending on whether the placement of these systems will be detrimental to the heating or plumbing design.

The usual location for boilers is in the kitchen or the utility room, and for cylinders it is normally airing cupboards. However, recently, as homeowners increasingly want more space, many builders have been moving boilers out of the kitchen and into garages, airing cupboards, lofts and WCs.


Radiators should ideally be placed beneath window sills, as cold air entering the room is heated by the convective air. If radiators are placed away from windows then cold air is drawn across the room to the radiators, creating a draft.

The size of the room needs to be considered when allocating wall space for radiators. The heating reach is usually 2.5 metres from the radiator, and therefore if seating areas are situated outside of this range, cold spots may be experienced by the occupants.


The flue position is critical, as boundary lines must be followed while still being aware of window openings and nuisance from plumbing. Installers should consult the boiler manual for guidance on positioning the flue to maintain the minimum clearances and prevent any issues arising in the future.

Room thermostats

As well as selecting the correct thermostat for the system, the location of the thermostat has a major effect on comfort levels and efficiency of the system. While there is no perfect location to suit every property, there are some pitfalls that should be avoided. These include installing thermostats in rooms that have another heat source, installing thermostats in small enclosed rooms, and fixing the thermostat on the adjoining walls of a cylinder cupboard, as this will affect the temperature reading.


It is important to take all the required steps to achieve the most suitable design for properties. There are some key commissioning procedures to ensure trouble-free operation.

Once a system has been installed, it needs to be flushed so that any debris from the installation process can be cleaned out of the system. The system should then be filled with the correct quantities of the relevant water treatment solution. This can all be performed before the boiler is fitted to the system, therefore protecting it from all the debris and allowing it to be fitted straight into a clean system. For new build properties, this also prevents boiler theft as the boiler doesn’t need to be installed until the property has been sold.

Failure to clean the system and treat it with the correct chemicals can lead to system failure, as sludge and debris will cause the heat exchanger to fail and reduce efficiency, while causing corrosion to the heating system.

A full commissioning process must take place once the heating system has been installed. This is an essential part of the process as it enables the system to function correctly and provides a record for future checks to maintain system efficiency.

By installing the right system for the property and placing equipment in the correct location in the home, homeowners’ heating and hot water demands can be sufficiently met. This ensures that the chosen heating system will provide comfort, trouble-free operation and efficiency.

Bill Jones is business development director at Potterton