PAS 2035
PAS 2035:2023 Retrofitting dwellings for improved energy efficiency - Specification and guidance is one of a number of Publicly Available Specifications covering retrofit, refurbishment and building upgrades. The others public specifications include; PAS 2030:2023 Installation of energy efficiency measures in existing dwellings and PAS 2038:2021 Retrofitting non-domestic buildings for improved energy efficiency.
PAS 2035:2023 (Incorporating Corrigendum No. 1) Retrofitting dwellings for improved energy efficiency – Specification and guidance describes retrofit building physics, building pathology, thermal models and calculations, approaches to retrofit in the medium term and at scale, performance considerations, standards and constraints, fabric first, interfaces, wholedwelling assessments, distressed replacement, retrofit designs, testing, commissioning and handover. It also also describes the various retrofit related roles, such as the main contractor and retrofit installer, retrofit advisors, coordinators, assessors, and evaluators aswell as standards, frameworks, competency and qualifications relating to these roles.
The PAS document says "Statutory national targets for the reduction of greenhouse gas emissions in response to the threat of climate change imply that very significant improvements need to be made in the energy efficiency of the UK’s building stock, including nearly all its 27 million domestic buildings. The Climate Change Committee sets “carbon budgets” under the Climate Change Act 2008, and the Government’s Net Zero Strategy includes a commitment to improvements in Energy Performance Certificate (EPC) scores in existing dwellings." It goes on to say that it "supports work towards those objectives by promoting and defining technically robust and responsible “wholedwelling” domestic retrofit work, i.e. highquality work that supports:"
- "a) improved functionality, usability and durability of buildings;
- b) improved comfort, health and wellbeing of building occupants and visitors;
- c) improved energy efficiency, leading to reduced fuel use, fuel costs and pollution (especially greenhouse gas emissions associated with energy use);
- d) reduced environmental impacts of buildings;
- e) protection and enhancement of the architectural and cultural heritage as represented by the building stock;
- f) avoidance of unintended consequences related to any of the above;
- g) minimization of the “performance gap” that occurs when reductions in fuel use, fuel cost and carbon dioxide emissions are not as large as intended or predicted; and
- h) protection of the general public and the client in relation to retrofit work."
[edit] Related articles on Designing Buildings
- Alterations to existing buildings.
- Do the building regulations apply to works to existing buildings?
- Demolition.
- Material amendment.
- Material change of use.
- Minor material amendment.
- Non material amendment.
- Change of use class.
- PAS 2038:2021 Retrofitting non-domestic buildings for improved energy efficiency.
- Planning permission.
- Permitted development.
- Principal designer.
- Renovation v refurbishment v retrofit.
- Retrofit.
- Retrofit projects and roles
- Types of work to existing buildings.
Featured articles and news
The need for a National construction careers campaign
Highlighted by CIOB to cut unemployment, reduce skills gap and deliver on housing and infrastructure ambitions.
AI-Driven automation; reducing time, enhancing compliance
Sustainability; not just compliance but rethinking design, material selection, and the supply chains to support them.
Climate Resilience and Adaptation In the Built Environment
New CIOB Technical Information Sheet by Colin Booth, Professor of Smart and Sustainable Infrastructure.
Turning Enquiries into Profitable Construction Projects
Founder of Develop Coaching and author of Building Your Future; Greg Wilkes shares his insights.
IHBC Signpost: Poetry from concrete
Scotland’s fascinating historic concrete and brutalist architecture with the Engine Shed.
Demonstrating that apprenticeships work for business, people and Scotland’s economy.
Scottish parents prioritise construction and apprenticeships
CIOB data released for Scottish Apprenticeship Week shows construction as top potential career path.
From a Green to a White Paper and the proposal of a General Safety Requirement for construction products.
Creativity, conservation and craft at Barley Studio. Book review.
The challenge as PFI agreements come to an end
How construction deals with inherited assets built under long-term contracts.
Skills plan for engineering and building services
Comprehensive industry report highlights persistent skills challenges across the sector.
Choosing the right design team for a D&B Contract
An architect explains the nature and needs of working within this common procurement route.
Statement from the Interim Chief Construction Advisor
Thouria Istephan; Architect and inquiry panel member outlines ongoing work, priorities and next steps.
The 2025 draft NPPF in brief with indicative responses
Local verses National and suitable verses sustainable: Consultation open for just over one week.
Increased vigilance on VAT Domestic Reverse Charge
HMRC bearing down with increasing force on construction consultant says.
Call for greater recognition of professional standards
Chartered bodies representing more than 1.5 million individuals have written to the UK Government.





















