Plain-English guides to SAP Calculations, Part L compliance and energy assessments for builders, architects and self-builders.
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Passing Part L Extension Rules Without a Full SAP Calculation
When you’re told your extension needs a SAP calculation, it can feel like another costly hurdle in an already expensive build. But…
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Building Regs Wall U-Values
There are two building regs wall u-values in Approved Document L for new builds and extensions. It is best practice to design…
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Building Regs U-Values: Limiting & Notional Values
Table of Building Regulations U-Values for New Dwellings in England Limiting U-Value (W/m2K) Notional U-Value (W/m2K) External walls 0.26 0.18 Floor 0.18…
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Manchester Local Plan: What It Means for Building Compliance
Manchester’s new building standard lands in 2027 with Passivhaus-level targets. Find out how it differs from the Future Homes Standard and what…
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Understanding DFEE: Why Fabric Matters More Than Renewables
DFEE measures your building’s fabric performance, unlike DER, you can’t fix it with solar panels. Learn why getting it wrong leaves you…
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BREL Reports Explained: What They Are and Why You Need One
What is a BREL report? The Part L compliance document from your SAP calculation. Required for all new builds in England before…
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What Software is Used For SAP Calculations in 2026
SAP software explained: Elmhurst & JPA Technical, how calculations work, and why you need qualified assessors. Plus 2026 pricing and HEM transition.
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SAP vs SBEM: Which Energy Assessment Do You Need?
Confused about SAP vs SBEM? This guide explains exactly which energy calculation you need for your project, from mixed-use to student accommodation.
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How Roof Insulation Affects Your SAP Calculation
SAP 10 is sensitive to roof heat loss. This short guide explains how insulation thickness, timber bridging and ceiling-level insulation influence results.
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How to Pass SAP: The Practical Checklist for Builders
Most SAP failures are avoidable. They usually come from small changes during the build that were never fed back into the calculation,…
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How Air Tightness Affects Part L Compliance
Airtightness is one of the biggest influences on SAP compliance. Here’s how leakage affects your numbers, what Part L expects and why…
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Part L 2021: What Builders Must Do to Stay Compliant
Part L 2021 changed how new homes must be built. This guide explains the key requirements and what builders need to provide…
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