SAP Calculations For New Builds

New Build Energy Regulations

Reducing wasted energy in properties is definitely more important than ever. Which is the reason the Government now have set strict energy targets on brand new constructed properties. So there are rigorous targets to make certain that newly built properties will be more comfortable to live in and have significantly cheaper running costs.

All newly built properties in the uk have to comply with Part L1A (Conservation of fuel and power).

Under this regulation –

Reasonable provision shall be made for the conservation of fuel and power in buildings by:

a) limiting heat gains and losses –

 I. through thermal elements and other parts of the building fabric; and
II. from pipes, ducts and vessels used for space heating, space cooling and hot water services;

 b) providing fixed building services which –

 I. are energy efficient;
II. have effective controls; and
III. are commissioned by testing and adjusting as necessary to ensure they use no more fuel and power than is reasonable in the circumstances.

Because a new home is basically a blank canvas, these targets are very demanding. However if you have sap calculations carried out prior to the building commencing then compliance is built in and it’s certain that the building will pass on completion.

The sap calculations should be done at the design stage from the architectural drawings. At this stage if any section of the construction isn’t compliant, suggestions and recommendations can be made to make it so. At stage building control can affirm that you will be building a compliant home and consequently let building work to commence. Any changes made to the property during its construction needs to be advised to the Sap Assessor to make certain that it still conforms.

Once the building is finished, the as built sap calculations are run again taking into account any changes made throughout the construction. Once the building passes, an energy performance certificate (EPC) is issued by the Assessor. The sap calculations and EPC will then be provided to building control for signing off.

In the real world we find many builds where no design stage sap calculations were carried out and the calculations are just requested once the building is done. Although this can be done, if the building isn’t compliant, then your options to make it compliant are usually more limited and could be more expensive at this point. Building control are a lot less flexible on non-compliances on new builds than they are on other types of projects.

Demonstrating Compliance

The Sap Calculations are needed to demonstrate compliance in 2 areas..

1. The Dwellings Carbon Emission Rate (DER) must be no more than the Target Emission Rate (TER). The target emission rate is determined in the software program by a “notional” property of the identical size where all the elements conform.

2. The Dwelling Fabric Energy Efficiency (DFEE) must be no more than the dwelling Target Energy Efficiency (TFEE). Again the Dwelling Target Energy Efficiency is produced from a model notional property the exact same size and shape where all of the thermal elements conform.

In order to carry out the calculations you will need to provide your Sap Assessor with the following:

• Floor Plans to include sections and elevations
• Orientation
• Construction specification of walls, roof and floors
• Specification for all doors and windows
• Primary and secondary heating
• Provisions made for hot water
• Any renewable technology (if any)

What you will receive

• All the relevant SAP documentation to include
• Compliance report
• U-value calculations
• An Energy Performance Certificate (EPC) on completion
• Additional advice and recommendations to ensure the dwelling achieves compliance.

To achieve the necessary targets, an air tightness test is also required and the thermal values of the property fabric will usually need to be higher than that described in the building regulations. We are able to assist if you require sap calculations in or around London or indeed anywhere in the UK. 

Contact us today for advice or assistance.

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