From February 2023, boiler efficiency standards were increased for all new and replacement boilers in Scotland, according to the Scottish House Condition Survey 2024 Key Findings1. The report states that "from February 2023 boiler efficiency standards were again increased for all new and replacement boilers"1.
The standards set minimum efficiency levels by boiler type. Condensing standard or combination gas boilers must reach 92%, oil condensing standard boilers 91%, and oil condensing combination boilers 86%1. The survey report does not set out the standards that applied before February 2023, so the size of the increase has not been reported1.
| Boiler type | Minimum efficiency from February 2023 |
|---|---|
| Condensing standard or combination gas | 92% |
| Oil condensing standard | 91% |
| Oil condensing combination | 86% |
The change sits alongside other Scottish heating regulation. From April 2024, the New Build Heat Standard only allows zero direct emission heat solutions, a definition that includes heat networks, bioenergy and peat, to be installed in new builds1. The same report notes that Energy Performance Certificates were introduced in January 2009 under the EU Energy Performance Building Directive2.
The Scottish House Condition Survey is based on a national survey of the housing stock, with 2,902 properties surveyed in 20241. It combines a householder interview with a physical inspection of the dwelling1. The 2024 report was published in February 20261.
Why it matters for households
Boiler efficiency determines how much of the energy in the fuel a boiler turns into useful heat, so a higher minimum standard affects the running cost of a replacement appliance over its life. For a household replacing a boiler, the standard sets the floor for what can be installed, which shapes both the purchase decision and the expected gas or oil consumption afterwards. The Boiler Efficiency, ErP Ratings and SEDBUK guide explains how efficiency is rated and labelled, and Condensing Boilers: How They Work covers the technology behind the condensing models that meet the higher thresholds.
For homes off the gas grid, the oil boiler minimums are lower than the gas equivalents, which reflects the different technology rather than a difference in running cost. The Grant Vortex oil boiler page covers one oil range and its efficiency. Households weighing a gas replacement against alternatives can compare the tepeo Zero Emission Boiler against a gas boiler, and the Gas Boilers guide sets out types, efficiency and fuel.
Efficiency standards are one part of a home's overall energy performance. Insulation levels, heating controls and how a boiler is set to run all affect consumption. The Boiler Flow Temperature guide covers how flow temperature settings affect efficiency in use. For households in Scotland considering support, Boiler and Heating Grants in Scotland sets out the grant landscape.
The wider regulatory picture includes the New Build Heat Standard, which applies to new builds rather than replacements, and EPC Regulations and the Reform of Energy Performance Certificates, which governs how a home's energy performance is rated and recorded. The regulation-policy hub and boilers-heating hub collect the related guides.
What happens next
The Scottish House Condition Survey 2024 Key Findings states that a Local Authority level analysis will follow the report, using a three year pooled data set covering 2022 to 2024, with estimates expected to be published in mid 20261. No further change to the boiler efficiency standards has been reported1.
Sources2 cited
- Key+Findings+2024+-+Complete+report.pdf, gov.scot
- Key+Findings+2024+-+Complete+report.pdf, gov.scot