SAP calculations for heavily glazed extensions
If you build an extension where the glazing is over 25% of the floor area, then we can undertake a SAP assessment to demonstrate compliance with Approved Document L1B.
Using SAP, we can provide you with an economic and feasible solution to ensure your extension achieves compliance, no matter how much glazing you wish to include in the design.
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FAST
– receive your results within 5 working days.
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RELIABLE
– we will provide you with all the documentation required to demonstrate compliance. No hidden extras and no hidden charges.
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VALUE
– we aim for every quote to be the most competitive. Our service includes all the support required to ensure every project achieves a pass.
Call now for a quote.
Three steps to compliance:
- Use SAP to calculate the CO2 emissions for the existing house along with the proposed extension.
- Calculate the CO2 emissions for the existing house with a notional extension. A notional extension is an extension that meets the minimum standards of Approved Document L1B.
- Compliance is achieved provided the “proposed” CO2 emissions are no greater than the “notional” CO2 emissions.
What is SAP?
The Standard Assessment Procedure ("SAP") is the Government's approved methodology for calculating the energy performance of dwellings.
How long does a SAP assessment take?
We aim to complete every SAP assessment within five working days.
What happens if my extension fails the SAP assessment?
Our assessors will be happy to provide you with a free consultancy service, advising you on all necessary amendments to ensure a pass is achieved every time.
How can Energytest help me?
We can provide an economic and feasible solution to ensure your extension achieves compliance, regardless of how much glazing you wish to include in your design. Options for achieving compliance include:
- Installing high levels of insulation within the fabric of the proposed extension;
- Adding insulation to the existing dwelling (for example, adding insulation to an existing loft space);
- Upgrading an existing heating system(s); or
- Adding renewable technology, such as photovoltaics or solar hot water panels.
What do I need to provide to the SAP assessor?
- Plans, elevations and sections for both the existing dwelling and the proposed extension;
- A detailed specification for the construction of all floors, roofs and external walls within the proposed extension;
- An approximate age and construction type for all floors, roofs and external walls within the existing dwelling (for example, 1970s cavity wall);
- Specification for all windows and doors within the buildings external envelope, including frame material, width of gap (if multiple glazing) and emissivity of glass;
- Details of the primary heating system (such as the make and model of the boiler) and associated controls;
- Details of any mechanical ventilation (for example, the number of mechanical extract fans);
- The number of standard light bulbs and the number of low energy light bulbs;
- Details of the hot water system, including cylinder size, details of any insulation to the cylinder and pipes, and associated controls;
- Details of any fixed secondary heating, cooling, and hot water systems (such as open fire place); and
- Details of any renewable technology, such as solar hot water, photovoltaics, or wind turbines.
Please follow this link for more details regarding Part L1B SAP calculations for heavily glazed extensions.
