What is Part L of the Building Regulations
“Part L” of the building regulations in England refers to the section of the regulations that deals with the conservation of fuel and power in buildings. This part of the regulations sets requirements for the energy performance of new and existing buildings, including standards for insulation, heating systems, and overall energy efficiency. It aims to reduce carbon emissions and improve the energy efficiency of buildings.
A copy of which can be obtained by clicking here.
What are SAP Calculations?
SAP, an acronym for ‘Standard Assessment Procedure,’ is the sole official and government-endorsed method for evaluating the energy efficiency of new homes. Accreditation and registration with a certification body are prerequisites for individuals acting as SAP assessors.
A SAP Rating serves as a means of comparing the energy performance of various homes, yielding a numeric value ranging from 1 to 100+ (where 100 signifies no energy costs, and values above 100 imply energy surplus). A higher SAP rating correlates with reduced fuel expenses and diminished carbon dioxide emissions.
SAP Calculations determine the energy costs based on factors like home construction, heating systems, internal lighting, and the incorporation of renewable technologies. Notably, these calculations do not account for energy consumption related to cooking or household appliances.
While SAP Calculations may seem perplexing and vexing, they play an indispensable role in the design of new homes in the UK.
They are a mandatory stipulation of the Building Regulations, applicable to all newly constructed dwellings in the country. Since 1995, a SAP Rating has been a prerequisite for all new homes under Part L of the building regulations, which means that most seasoned developers are well-acquainted with it.
Nevertheless, for many first-time self-builders and developers, SAP Calculations may represent a novel and sometimes daunting facet of the planning and building control process.
SAP Calculations serve three primary functions:
- Establishing a SAP Rating, which quantifies the energy-related operational expenses of a dwelling.
- Demonstrating conformity with Part L of the building regulations.
- Generating an Energy Performance Certificate (EPC).
It’s worth noting that you might also require SAP calculations for conversion or extension projects, with specific rules and considerations, and that Scotland has its own unique requirements in this regard.
Demonstrating Part L Building Regulation Compliance
Compliance with SAP Calculations is imperative for home builders to meet current building regulations. Without obtaining a ‘pass’ in these calculations, building control will not grant approval for the development, and the property cannot be legally leased or marketed for sale.
However, the significance of SAP extends beyond mere regulatory compliance. SAP assessors play a pivotal role in assisting designers and architects in shaping the energy efficiency of a new dwelling, thereby reducing its energy consumption and carbon emissions.
These assessments provide a precise gauge of the impact of various construction methods, heating systems, and technologies, ensuring that energy efficiency measures are effectively implemented.
Additionally, the SAP rating serves as a public indicator of a property’s energy performance, informing the creation of the Energy Performance Certificate (EPC) that is visible to prospective buyers and tenants.
To achieve a ‘pass,’ several compliance targets must be met, encompassing aspects such as the thermal efficiency of the dwelling’s structure, solar gain, construction quality, and the performance of systems, as well as predicted CO2 emissions from the dwelling.
Reduce Emissions and Improve Fabric
Ever heard of the expression, fabric first? By reducing demand by improved fabric and reduce emissions.
The primary emissions target is met through the use of DER/TER values, where carbon dioxide (CO2) emissions are assessed by contrasting the Target Emission Rate (TER) with the anticipated Dwelling Emission Rate (DER).
The TER is established in SAP calculations by referencing a notional dwelling of comparable size and shape, employing a predefined set of baseline values.
Of significant note, these CO2 emissions data are increasingly harnessed by urban planners and local councils to advance various objectives, encompassing sustainability goals, local renewable energy policies, and the determination of community contributions under initiatives like Section 106 agreements.
In England, homes constructed after April 2014 are additionally evaluated for their Fabric Energy Efficiency. This assessment is not focused on carbon emissions but rather on energy demand, quantified in kilowatt-hours per square meter per year. A home’s ability to retain the heat it generates plays a vital role in both its CO2 emissions and its independent compliance assessment.
The evaluation of Fabric Energy Efficiency involves the use of DFEE/TFEE figures. Similar to emissions, the target for this metric is established within the SAP framework, relying on a set of baseline values that vary according to the size of the property.
The SAP Calculation Process
A SAP Assessor commences their work by utilizing architectural plans and construction specifications in conjunction with a comprehensive HVAC (heating, ventilation, and air conditioning) specification. Consequently, the drawings must be meticulously scaled, accurate, and encompass all facets, including elevations, sections, floor plans, and site layouts.
The assessor then proceeds to create a model of the dwelling(s) within SAP software, working from these scaled plans, whether manually or electronically. This digital representation forms the foundation for SAP Calculations.
Within this model, the assessor integrates the heating, lighting, and ventilation systems, selecting specific products from manufacturer databases when applicable. Detailed thermal elements, encompassing walls, floors, roofs, and openings, are meticulously included, along with calculations for thermal junctions. Additionally, any renewable technologies and cooling systems are incorporated.
Upon finalization, the SAP calculation generates an array of comprehensive reports, spanning site layout, heat losses, energy demands, seasonal variations, CO2 emissions, renewables contributions, and numerous other aspects.
Hints and Tips
We conduct daily SAP Calculations for various projects, from self-builds to apartment complexes. However, the key point is to start early. Late plans leave limited room for improving a building’s energy performance, often leading to poor practices and expensive, last-minute fixes for compliance.
- Engaging with your SAP Assessor as early as possible—prior to planning and building regulation applications—is vital.
- Challenge Minimum U-Values: Exceeding minimum U-Values reduces reliance on costly renewable tech.
- Optimize Windows and Doors: Choose openings with U-Values of 1.2 W/m²K or less.
- Prioritize Control Systems: Effective heating controls are pivotal.
- Ensure Airtightness: Test and seal the envelope,
- Address Thermal Bridging: Mitigate heat loss at junctions with schemes like Registered or Modelled Construction Details.
Part L for Existing Buildings and Retrofits
SAP Calculations under Part L1of the building regulations are typically necessary for various project types, including:
- Extensions with over 25% glazing-to-floor area (SAP Calculations for Extensions).
- Barn conversions.
- Conversions from commercial to domestic use.
- Conversion of a single dwelling into flats or apartments.
- If more than 50% of any building fabric element is considered to be having ‘building works’.
Let’s Talk About Your Project
Just give us a call on 01621 493594 , or email us at contact@buildingcompliancetesting.com