Introduction
When building a new home, airtightness is key to comfort, energy efficiency, and long-term durability. Even small gaps around windows, doors, or service penetrations can lead to heat loss, drafts, and condensation. In the UK and Ireland, strict standards exist to ensure new builds meet energy efficiency and indoor air quality requirements. In this guide, we’ll explore the standards, testing procedures, and best practices for achieving airtightness, helping your home stay warm, dry, and cost-effective.
Why Airtightness Matters in New Builds
Air leakage is a hidden problem in many new constructions. Even well-insulated walls can lose significant heat through gaps and unsealed joints, increasing energy bills and reducing comfort. Poor airtightness can also cause condensation, damp, and mould issues, particularly in corners and around ceilings.
Ensuring a continuous air barrier across the building envelope is essential for compliance with building regulations and energy efficiency standards. For a detailed guide on maintaining high performance, see our how airtightness works.
Airtightness Standards in the UK and Ireland
UK Standards
- Part L of the Building Regulations: Sets energy efficiency requirements for new dwellings, including maximum air permeability targets (usually ≤ 5 m³/h/m² at 50 Pa).
- PAS 2035 & 2030: Focus on retrofit and new build airtightness to support energy efficiency improvements.
- BRE Best Practice Guides: Provide detailed advice on airtight construction methods and materials.
Ireland Standards
- NZEB (Nearly Zero Energy Buildings) Regulations: Require airtightness testing for new builds to achieve high energy performance.
- Technical Guidance Document L: Sets the recommended air permeability targets (typically ≤ 5 m³/h/m² at 50 Pa) and specifies testing protocols.
These standards ensure homes are energy-efficient, reduce carbon emissions, and maintain healthy indoor air quality.
Airtightness Testing Procedures
Airtightness testing is the most reliable way to confirm compliance with UK and Ireland standards. The blower door test is the industry standard:
- Set Up: A temporary frame with a calibrated fan is installed in an external door opening.
- Measurement: The fan depressurises the home to a standard pressure (usually 50 Pa).
- Detection: Air leaks are identified with smoke pens or thermal imaging.
- Reporting: The air permeability result (m³/h/m²) is compared to regulatory limits.
Regular on-site inspections during construction help catch leaks before finishes are applied, ensuring the final test passes without costly remedial work.
How to Achieve Airtightness
Creating an airtight home requires careful planning and attention to detail:
Creating an airtight home requires careful planning and attention to detail:
- Continuous air barriers: Use membranes, sealants, or airtightness paint across walls, ceilings, and floors.
- Sealed penetrations: Ensure pipes, ducts, and wiring are properly sealed.
- High-performance windows and doors: Correct installation and sealing are crucial.
- On-site inspections: Check for gaps at each construction stage to avoid hidden leaks.
Airtightness paint is a simple yet effective solution. Applied to internal walls and ceilings, it forms a continuous air barrier that reduces leakage, improves energy efficiency, and helps homes pass blower door tests.
Key Benefits of High Airtightness
- Reduced heat loss, lowering energy bills
- Improved indoor comfort with fewer drafts
- Minimised condensation and damp risk
- Compliance with UK and Ireland building regulations
- Supports long-term energy-efficient home performance
Supporting Airtightness Products
- Airtight Membranes – Continuous barriers across walls and roofs
- Sealants & Tapes – Perfect for penetrations and joints
- Airtightness Paint – Easy-to-apply solution to create seamless internal air barriers
Trust & Expertise
Heat Recovery Direct has extensive experience advising on airtight construction. Our team provides guidance and products that help builders and homeowners meet UK and Ireland standards, ensuring homes are energy-efficient, durable, and comfortable.
Conclusion
Airtightness is critical for energy-efficient new builds in the UK and Ireland. By sealing gaps, following standards, and using proper testing procedures, your home will stay warm, dry, and cost-effective.
👉 Contact our team for expert airtightness advice or explore our range of airtightness products.
FAQ
What is the recommended airtightness level for new builds in the UK and Ireland?
Typically, new builds should achieve ≤ 5 m³/h/m² at 50 Pa, meeting Building Regulations Part L (UK) and Technical Guidance Document L (Ireland).
How is airtightness tested in new homes?
A blower door test depressurises the house to detect leaks. Smoke pens or thermal imaging highlight areas needing attention.
Where are homes most prone to air leaks?
Common spots include around windows, doors, roof-wall junctions, skirting boards, and service penetrations.