Heat-loss Building
3rd January 2020
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Differences between new build EPCs and EPCs for previously constructed buildings

The letters’ SAP EPC’ reference Energy Performance Certification issued in accordance with SAP methodology and employing SAP software. Such certification is issued by an ‘On-Construction Domestic Energy Assessor.’

SAP EPC

SAP calculations are how the energy performance of new UK homes is determined. SAP calculations are a requirement for all new homes, converted dwellings or dwellings subject to a change of use. Specialist assessors use SAP calculations to create an EPC outlining the energy efficiency of each tested building.

Assessors derive part of their results from architectural drawings, together with construction, ventilation, and heating information.

EPC’s for Existing Dwellings

The majority of EPC’s relate to existing homes for sale or let. At one time, this sort of EPC formed part of the potential home purchaser’s or tenant’s Home Information Pack. At present, Home Information Packs are no longer used, and a new process for delivery of EPCs has been put in place.

First, a Domestic Energy Assessor visits the dwelling and carries out a survey. To produce the EPC, the assessor carries out a simplified energy assessment called an RDSAP (Reduced Data SAP). In cases where the inspection fails to yield precise details of how a home has been assembled, the RDSAP methodology may incorporate age-based values and assumptions to help assessors reach meaningful conclusions.

Essentially both types of EPC are identical. Both provide snapshots of the dwelling’s energy efficiency and costs. It’s just that one is constructed from highly detailed construction and service specs and architectural drawings (SAP EPC). The other type relies on on-site surveys. In general, EPCs for existing homes tend to be cheaper to purchase than those derived from SAP Calculations.

SAP Calculations and Extensions

Who doesn’t want plenty of light?

Part L1b of the current Building Regulations determines that new glazing must tot exceed twenty-five percent of the new floor area. Extension designs often propose higher percentages, and so render themselves non-complaint. This is where we can help. SAP Calculations are generated by energy assessors holding industry derived accreditations. These calculations can help demonstrate how your specific proposal may remain building reg compliant and still incorporate substantial amounts of glazing.

How do SAP Calculations for Extensions Work?

More heat escapes through glazing than is lost through roofs and walls. This explains why Building Regulations set limits. It is possible to reduce the negative effects of large-scale grazing by upgrading or over-compensating when constructing other areas. Or by demonstrating other solar gains conferred by additional glazing.

These are not the only options that take account of upgrades to an existing dwelling. ‘Change-of-use’ schemes may also fall under SAP regulations, with examples including flat conversions and commercial-to-residential conversions.

What’s Needed?

To carry out a full SAP L1b assessment, your assessor requires:

  • A set of plans for the existing property
  • A further set of plans for the proposed property (scaled)
  • A detailed summary schedule of all intended construction and services proposals

This is enough to allow the assessor to carry out a desktop assessment. No site visits or surveys will be required.

We specialise in SAP Calculations For Extensions

Every day, nationwide, we help 100s of contractors, architects, and homeowners make large numbers of SAP Calculations for extensions. We are therefore best placed to offer guidance and advice in such matters. If necessary, we can deal directly with your Building Control Officer, taking care of everything on your behalf.

EPC’s, SAP & BRUKL: A Planning Guide

It is the responsibility of an energy assessor to produce SAP, BRUKL, and EPC documentation for new buildings. Such documents offer evidence about how a new build is compliant with the regulations for lower carbon designs.

The EPC is the sole document audited by the accreditation body that governs Energy Assessors’ professional conduct. This renders the EPC the most comprehensive verification of the accuracy of the SAP or BRUKL document for third parties.

This short guide has been designed to help third parties understand the documentation and to make sense of what precisely the document says about a building’s energy performance. We’ll explain differences between SAP, BRUKL, and EPC reports, as well as what is meant by the terms’ design’ and ‘as built.’

What kind of information will I find in EPC, SAP, or BRUKL Documentation?

SAP & BRUKL reports verify compliance with Part L of the Building Regulations for energy conservation. Planning authorities occasionally reference these documents to check compliance against low-carbon targets. But perhaps the clearest distinction between Standard Assessment Procedure documents & Building Regulations UK, Part L documentation is that the former relates to dwellings. At the same time, the latter is concerned with non-domestic dwellings.

BRUKL documents may also be referred to as Simplified Building Energy Model reports. Both documents record a Dwelling Emission Rate (known as a DER) or a Building Emission Rate (known as a BER). Both figures predict the amount of carbon generated by the building in kilograms per square metre per annum and for new buildings must not exceed the TER (Target Emission Rate). Target Emission Rates are bespoke for each dwelling. They are the key deliverable of Part L of the Building Regulations.

Part L contains other rules which rely on SAP and BRUKL documentation, including a domestic Target Fabric Energy Efficiency and minimum scores for fabric and equipment performance.

EPC certification contains information targeted at consumers, which facilitates easy comparison between properties regarding running costs, amongst other things.

EPC, SAP, and BRUKL reports may be issued only by an accredited energy assessor working from government-sanctioned computer applications. These documents may vary in look from provider to provider; however, the information they contain is derived from identical data and methods. In some cases, specific assessors add bespoke summaries of their results and assumptions to the standard output.

What do the terms’ design stage and as built mean?

SAP & BRUKL reports are produced at the design stage of a project and are intended to be predictive, based as they are on a design team’s spec or an assessor’s recommendation. They do not confirm the final performance. Instead, they predict outcomes based on accurate dimensions and specs which remain unaltered throughout construction.

The term ‘As built’ refers to reports generated post-construction and intended to reflect the finished building accurately.

EPCs are generated along with ‘as built’ documents after verification — typically emerging from a mixture of on-site tests, certification from third parties, and self-declarations.

Energy Performance Certificates from Briary Energy

We issue EPCs just before the project comes to an end where residential new builds, conversions, and extensions are concerned. Our STROMA-accredited engineers will issue a residential EPC.

These following actions are carried to dot the I’s and cross the T’s:

  • We check that the Dwelling Emissions Rate (DER) meets the Target Emissions Rate (TER) determined by your SAP calculations.
  • We determine any changes or updates to the building’s fabric, cooling, heating, or ventilation systems.
  • We allocate an EPC rating between A–G, where A indicates the most energy-efficient and G, the least.
  • We Log the property in the government’s landmark register to officially complete the EPC certification process.

In general, dwellings are required to have an updated EPC once a decade. However, one may be necessary sooner where a major change has occurred — the introduction of a new heating system, for example.

Why Choose Us?

  • Discounts for SAP/SBEM Calculations
  • Full UK Coverage
  • Experienced and Accredited Team
  • Practical Advice
  • Same Day Certificates

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