Frequently Asked Questions
Please click on the links below to take you to your desired FAQ:
What are Accredited Construction Details?
What is a UPRN and RRN?
Why do I get a poor rating when my building is electrically heated?
My house was built under the 2002 edition of PartL Building Regulations. How do I obtain my EPC?
Why does a heat pump produce a good DER or BER figure but produce such a poor SAP or SBEM rating?
How does under floor heating affect my Dwelling Emission Rate?
How does a mechanical ventilation with heat recovery affect my rating?
What is SAP and why do I need a SAP calculation?
Standard Assessment Procedure (SAP) calculations are a mandatory requirement for any new build dwelling. SAP is used to show compliance with Part L of the Building Regulations and is applied at the design stage of the build process.
SAP is the calculation methodology which determines the energy cost and carbon emissions generated to heat and light a dwelling. Please click here for DEFRAs full description of SAP.
What are Accredited Construction Details?
Accredited Construction Details (ACDS) deal with insulation continuity around the junctions of the build and the air tightness of the dwelling.
ACDS were introduced into the building regulations Part L on the 6th April 2006 and can be found on the Planning Portal website and downloaded FOC.
Accredited Construction Details are not a mandatory requirement of Part L of the Building Regulations, however, they can significantly improve your DER (Dwelling Emission Rate) or BER (Building Emission Rate) and help you to achieve compliance.
What is a UPRN and RRN?
When producing an EPC (Energy Performance Certificate) you will need to check with the Landmark Registry that the property in question is registered.
A UPRN is a Unique Property Reference Number, this number acts a unique identifier for each individual property in the UK. When your survey is lodged with Landmark, the EPC can be retrieved from the Landmark website www.hcrregister.com by using the EPC RRN (Report Reference Number).
Why do I get a poor rating when my building is electrically heated?
Although electric heating is 100% efficient it is very expensive compared to other fuel types. SAP and SBEM are part based on the cost of heating the building, therefore, the more it costs to heat the building the worse your rating will be. The same theory applies to your DER (Dwelling Emission Rate) and BER (Building Emission Rate) figure. As before, your electric heating system is 100% efficient but you will produce a greater amount of CO2, thus having a negative effect on your DER or BER.
There are many choices available in terms of electric heating. However, there are various types of 'more efficient' electrical heating options in the market place such as:
- Heat pumps
- Low energy panel heaters
An alternative would be to use a renewable energy source such as:
- Photovoltaic cells
- Solar panels
My house was built under the 2002 edition of PartL Building Regulations. How do I obtain my EPC?
We take the original SAP calculation and we import that calculation into the latest version of the software. This enables the EPC (Energy Performance Certificate) to be produced based upon the standards that your house was built in accordance with. Therefore, a change in the Building Regulations will not prevent you from obtaining an EPC. Please note that your rating may be slightly lower on your EPC, this is due to ever increasing energy standards.
Why does a heat pump produce a good DER or BER figure but produce such a poor SAP or SBEM rating?
A heat pump will produce a good DER or BER figure because the CO2 emissions from this system is very low, the SAP or SBEM rating on the other hand will be poor because:
- The initial cost of buying/installing the heat pump is higher than that of a gas fired boiler system.
- The heat pump has an electric back-up system and the cost of electric is high resulting in a poor SAP or SBEM outcome.
How does under floor heating affect my Dwelling Emission Rate?
If you are applying under floor heating to a screed or in a timber floor construction, this will have approximately the same DER compared to wet radiators.
If you are placing under floor heating within a concrete slab the DER will be poorer than that of a typical wet radiator system - this is due to the mass of the floor and it's resistance to react to changes in temperature.
How does a mechanical ventilation with heat recovery affect my rating?
Surprisingly, your Dwelling Emission Rate (DER) will be higher when incorporating a Mechanical Ventilation Heat Recovery (MVHR) system into your building. This is due to the fact that the system requires a constant electrical demand which omits CO2 - this is reflected negatively in the rating.
The more accurate the information when supplied to Elmhurst regarding your chosen system, will in turn allow for a more accurate rating.
My Dwelling exceeds 150msq in gross floor area. Will I need to improve the standard of my heating system?
For any new dwelling exceeding 150msq the heating system should be zoned to meet the general requirements of the Building Regulations.
Why do I need an 'As Built' calculation when I have had an 'As Designed' calculation produced and nothing has changed?
The 'As Built' calculation is required by building regulations. This is because at 'Design Stage' a number of assumptions could be made in order to complete the energy rating i.e. assumed heating details and pressure testing figures.
Any alterations from the original design that have taken place during construction will be taken into account on the 'As Built' calculation. i.e. Actual pressure testing results and specific heating details.
