Fuel Choice?

In choosing a fuel type for a building, a diverse number of factors will come into consideration, the main points of which are summarised below.

GAS CENTRAL HEATING
Specification Considerations
* For compliance with updated Building Regulations Part L1, a minimum boiler efficiency of 78% is required. In most cases this would assume the use of a condensing boiler.
* The building envelope will need to meet the minimum permitted U-Values laid out in Building Regulations document L1, although some flexibility is provided with the option to demonstrate compliance using the carbon index or target U-value methods.

(Refer to the Building Regulations section for further information on Building Regulations Part L1)

* For flats consider Building Regulations restrictions relating to siting of flues beneath ventilation ducts and windows.
* Consider the option of using combination boilers to provide hot water on demand, negating the need for hot water storage.
* Due to higher capital and on-site labour costs, installation of a gas central heating system can be as much as twice that of an electric heating system for a similar sized property.

Installation Considerations
* Installation of any gas appliance must be carried out by a CORGI registered installer.
* Consider the potential for damage to be caused by leaking or burst pipe work prior to completion of the property

Running Costs
* Due to lower unit energy prices, a gas central heating system will demand lower total fuel costs than an electric system, despite using more total kWh of energy.
* The cost of annual maintenance must also be considered within any running cost calculations.

(For further information on running costs, refer to the Running Costs section of the Cost of Ownership topic.)

Maintenance
* Advice from British Gas and manufacturers is for gas appliances such as boilers and fires to be serviced once a year to ensure they are working safely.
* Under the Gas Safety Act (1994), Landlords and Housing Associations are legally obliged by law to carry out annual safety checks.
(For further information please refer to the Maintenance section of the Cost of Ownership topic).

ELECTRIC HEATING
Specification Considerations
* In order to achieve compliance with Building Regulations Part L1, the building envelope will need to achieve U-Values of approximately 15% below the minimum permitted levels laid out in document L1.
* Use the target U-Value method of calculation to demonstrate compliance.

(Refer to the Building Regulations topic for further information on Building Regulations Part L1)

* For heavy-weight buildings (e.g. brick and block), a combination of storage and panel heaters should be used, to provide a mix of background heat to maintain warmth in the building fabric and provide controllable top up heat on demand.
* For light-weight buildings (e.g. timber frame), consider using fast response heaters, such as panels with electronic controls.
* For well insulated flats where running costs are less sensitive (i.e. private build), panel heaters may also be considered to meet the entire heating load, due to their low capital cost and added controllability.
* An electric heating system may be up to 50% cheaper to install than a gas central heating system, due to lower capital an on-site labour costs, helping to off set any marginal cost of improving the insulation specification in order to comply with building regulations.

Installation Considerations
* Installation of any electrical equipment must be carried out in compliance with IEE wiring regulations by a qualified electrician.
* Electric heaters may be fitted at a later stage of the building development, helping to improve cash flow and reducing the risk of products being stolen from site.
* Consider the weight of transporting storage heater bricks if required above ground floor level.

Running Costs
* Due to better system efficiency and higher building insulation levels required to comply with building regulations, the total energy usage will be lower than that for a gas central heating system. However fuel costs will be higher due to higher unit energy prices of electric.
* The cost of annual maintenance must also be considered within any running cost calculations.

(For further information on running costs, refer to the Running Costs section of the Cost of Ownership topic.)

Maintenance
* Electric heating does not require annual maintenance or safety checks, although it is recommended that all electric wiring be inspected every 5 years.
* There are no moving parts directly affecting the function of electric heaters, meaning the risk of breakdown or failure is low.
* Heaters in an all electric system work independently from one another, so a fault on an individual heater will not cause total system failure.

(For further information please refer to the Maintenance section of the Cost of Ownership topic).

Supply Infrastructure
* Where storage heaters are specified, the capacity of infrastructure to cope with the total electrical system load must be assessed to determine the after diversity maximum demand.
* For panel only schemes, when considering the capacity of the infrastructure, a suitable diversity factor must be applied to determine the after diversity maximum demand. It can be sensibly assumed that not all heating appliances will be required at full load at any one time.

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