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Retrofitting Britain’s homes is no longer an option- it’s a necessity. With over 17 million UK homes still below EPC C, meeting the 2050 net-zero target means retrofitting five homes per minute, every minute, for the next 30 years. That’s where the PAS 2035/2030:2023 framework becomes essential.

🔍 What is PAS? 

PAS stands for Publicly Available Specification—a fast-tracked framework for setting industry standards, aligned with the British Standards Institution (BSI). While the numbers (e.g., PAS 2030, PAS 2035) can appear arbitrary, they help distinguish between specific guidance such as PAS 911 for fire safety or PAS 2030 for energy efficiency in buildings.

For retrofit, PAS 2035 and PAS 2030 are the two standards that define how retrofit projects must be assessed, designed, installed, and evaluated ensuring high quality and consistency.

What’s Covered Under Each PAS?

PAS 2035 focuses on the process of retrofit and applies to all publicly funded domestic projects:

• Full dwelling assessment
• Evaluation and design of energy efficiency measures (EEMs)
• Monitoring, evaluation, and continuous improvement
• Advice to occupants on optimal use of their homes

PAS 2030 outlines the installation requirements for EEMs:

• Installation methods and materials
• Commissioning and service standards
• Installers’ training and qualifications
• Co-functioning of multiple measures in the same dwelling

These standards are enforced through TrustMark, the only approved certification body, which stores all project documentation for compliance and quality assurance.

Why PAS 2035/2030:2023 Matters

• Comprehensive: Covers the full retrofit journey, from assessment to evaluation.
• Free to access: Both PAS 2030:2023 and PAS 2035:2023 documents are freely available.
• Mandatory for public funding: Required for schemes like ECO4, SHDF, GBIS, HUG, and the new Warm Homes Local Grant.
• Efficient and collaborative: Enables stakeholders to work effectively with shared goals.
• Risk mitigation: Ensures safer, better-performing homes with fewer errors.
• Supports net-zero goals: Enables scalable, lasting energy savings aligned with the UK’s climate action plans.

What’s New in PAS 2035/2030:2023?

As of March 31, 2025, the 18-month transition period ended, making PAS 2035/2030:2023 the active standard. Key updates include:

• Greater focus on whole-house retrofit, replacing a measure-by-measure approach.
• New requirement for a Medium-Term Improvement Plan (MTIP).
• Stronger consumer protection clauses and alignment with national policy.
• Simplified risk assessment and revised qualifications for Retrofit Designers.
• Updated guidance on airtightness strategy, ventilation, moisture management, and climate adaptation.
• Recognition of BS 40101 for performance monitoring and BS 7913 for heritage buildings.

Practical Implications 

• Assessments done under PAS 2019 can often be upgraded to 2023 via software updates.
• Retrofit Coordinators can now take on the designer role for 1–2 measures. For 3+ measures, only certified professionals like chartered architects or building surveyors can design.
• Photographic evidence is more structured: pre-, mid-, and post-photos must be lodged under new categories in the TrustMark data warehouse.
• In-person inspections by Retrofit Coordinators are mandatory for interconnected measures.

Traditional Buildings & Heritage

Ventilation & Damp Prevention

Ventilation is aligned with Approved Document F. Where mould or condensation is evident, upgraded systems like MEV or MVHR must be specified. The incoming Awaab’s Law (Oct 2025) further enforces this, especially for social housing.

Final Thoughts

PAS 2035/2030:2023 provides a robust, technically sound framework for achieving energy-efficient homes across the UK. It ensures:

• High standards
• Consumer protection
• Consistent documentation
• Strong alignment with sustainability goals

At RetrofitWorks, we’re committed to upholding these standards across all our projects. Whether you’re a local authority, homeowner, or installer—PAS compliance is your roadmap to a warmer, safer, and net-zero future.

🔗 Useful Links:

• PAS 2035:2023 (BSI)

Top 5 Energy Efficiency Upgrades for Your Home in 2025

Enhancing your home’s energy efficiency is a strategic investment that can lead to significant cost savings and increased comfort. As we progress through 2025, several key measures have emerged as both effective and accessible for homeowners. Here are the top five energy efficiency upgrades to consider:

1. Comprehensive Insulation

Proper insulation is foundational to an energy-efficient home. Addressing areas such as lofts, walls, and floors can significantly reduce heat loss.

Key Areas to Insulate:

• Loft/Roof: Prevents heat from escaping upwards.
• Walls: Cavity wall insulation can lead to substantial energy savings.
• Floors: Insulating underfloor spaces enhances overall thermal efficiency.

2. Air Source Heat Pumps (ASHPs)

Transitioning to an air source heat pump offers an eco-friendly alternative to traditional heating systems. ASHPs extract heat from the outside air to warm your home, even during colder months.

Benefits:

• Lower carbon emissions.
• Potential reduction in heating costs.
• Efficient performance, even in colder climates.

3. Solar Photovoltaic (PV) Panels

Harnessing solar energy through PV panels allows homeowners to generate their own electricity, decreasing reliance on the grid. Integrating battery storage systems can optimize energy usage by storing excess power for later use.

Advantages:

• Reduced electricity bills.
• Lower carbon footprint.
• Potential earnings through schemes like the Smart Export Guarantee (SEG).

4. Smart Heating Controls

Upgrading to smart thermostats and heating controls enables precise management of your home’s temperature. Devices such as Google Nest or Hive learn your schedule and adjust heating accordingly, ensuring comfort while minimizing energy waste.

Features:

• Remote control via smartphone apps.
• Learning capabilities to optimize heating schedules.
• Energy usage reports to track and manage consumption.

5. Upgraded Glazing

Replacing single-glazed windows with double or triple glazing enhances thermal insulation, reducing heat loss and external noise. While the initial investment can be significant, the long-term energy savings and increased property value make it worthwhile.

Benefits:

• Improved thermal comfort
• Lower heating costs.
• Enhanced soundproofing.

By implementing these upgrades, homeowners can achieve substantial energy savings, enhance property value, and contribute to the UK’s net-zero emissions target. It’s advisable to consult with certified professionals to determine the most suitable measures for your home.

“Discover the top 5 energy efficiency upgrades for your home in 2025. Enhance comfort, reduce energy bills, and contribute to a sustainable future with these essential improvements.”