Standard Assessment Procedure calculations are a requirement for every new build dwelling in the UK.

This article will go through the procedures and best practices to ensure that your new build project is compliant to Standard Assessment Procedure calculations, also known as SAP calculations and all of the regulations require

1.Define the requirements your project needs to meet

Every new build will be required to meet Building Regulations Part L1a criteria, this regulation covers the conservation of power and outlines the requirements that your project must meet. However today’s demand on reducing carbon emissions at an all time high, additional criteria may be set for your project. It is always worth checking if any conditions have been set at planning stage for your project to improve upon Building Regulations, some criteria will require 10%, 21%, 35% etc.

2. Insulation, insulation, insulation

When it’s comes to meeting Building Regulations Part L1a SAP calculations, it is essential to ensure that your thermal elements, such as wall, floor and roof, are insulating to a high standard. It is common practice for thermal elements to be specified with the maximum value u-value allowable in Building Regulations, however when looking to ensure your SAP calculations comply, improving on these figures is almost always a must. Below outlines the MAXIMUM allowed u-values that we look to improve on.

• Wall/external facade – 0.28 W/m2K
• Floor – 0.22 W/m2K
• Roof (insulated at sloped or flat section) – 0.18 W/m2K
• Roof (insulated at ceiling level) – 0.16 W/m2K
• Glazing – 1.6 W/m2K
• Door – 1.8 W/m2K

Again, we would always look to improve in the above figures rather than just meet them.

3. Get your SAP Calculations completed as early as possible

This is an obvious one but so important to ensure your project runs smoothly. Completing SAP Calculations early opens the opportunity for a number of things,

• Ease of alterations to design to ensure compliance
• Possibility to review different options to reduce running cost or construction cost
• Take advice on other elements such as thermal/cold bridging details and air tightness.

4. Heating & Heating Controls

SAP Calculations review the C02 emissions produced by a dwelling and heating is one of the main factors for this, ensuring that the heating system & heating controls are designed in a way to reduce these emissions is a key element when it comes to compliance. if you are looking to use a boiler or you would like to review the options of an alternative heating systems such as air source heat pump, it is a crucial to ensure that the heating and heating controls are designed early and review if some small alterations to the system may be able to make a big difference to your calculations.

5. Renewable Technologies

Moving forward the criteria and regulations are becoming more stringent to work towards a carbon neutral target, the use of renewable energy sources could be a great way to not only ensure compliance to your SAP Calculations, but could also future proof your homes. the use of Solar PV, Solar water, battery storage, Air source Heat Pumps, Ground source heat pumps or wind turbines would dramatically reduce your carbon emissions as well as heating costs.

6. More points to consider

Thermal/Cold Bridging – Thermal bridging is a key point in ensuring compliance to new build regulations, this ensures that the weak point in your structure (junctions between elements such as wall & floor) minimise heat loss. well designed thermal bridging details will ensure a much easier route to compliance. discuss this with your assessor to find out more.

Glazing – When designing your project, it is essential to consider the u & g values of your glazing. openings in your facade are weak points as glazing will always be lower performing than the facade itself, therefore ensuring good performing glazing is specified can reduce the heat loss through these elements.

Secondary Heating – In some circumstances, installing secondary heating with a sustainable fuel such as a log burner, can assist in achieving compliance to New build SAP Calculations, discuss the potential of this with your assessor

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