Northern Ireland guidance

Ventilation & Building Regulations (Northern Ireland)

Ventilation requirements in Northern Ireland are set by the Building Regulations (Northern Ireland) and supported by Technical Booklet K. England’s Approved Document F is not the applicable guidance for Northern Ireland projects.

This page is a homeowner-friendly overview. A specific design must be assessed against the building, the proposed work and the current requirements.

The correct local framework

What Technical Booklet K covers

Technical Booklet K provides guidance supporting regulations 65, 66 and 68, which set requirements for ventilation in Northern Ireland.

Adequate ventilation is required

Ventilation should provide appropriate indoor air quality and control moisture while taking account of the building and its use.

Technical guidance is not one-size-fits-all

Following a Technical Booklet can create a presumption of compliance, but a different approach may be used if compliance is demonstrated to the district council.

Building Control assesses compliance

The relevant council’s Building Control service reviews the proposed work. It has the final decision on whether the project satisfies the Building Regulations.

Official sourcesDepartment of Finance: Technical Booklet K — Ventilation Department of Finance: current Building Regulations Technical Booklets Building Control Northern Ireland

Different ventilation strategies

MVHR is not the only option

Technical Booklet K describes more than one ventilation approach. The correct strategy depends on the design, airtightness, layout and type of work.

MEV

Mechanical Extract Ventilation continuously removes stale air from wet rooms. It is one recognised ventilation approach when designed appropriately.

MVHR

Mechanical Ventilation with Heat Recovery provides balanced supply and extract through ductwork. It is not mandatory for every property or project.

PIV

Positive Input Ventilation may be suitable in some circumstances, particularly in existing homes, but it is not automatically accepted as the complete ventilation strategy for every building.

Why the building design matters

Building Control may consider the property type, airtightness, existing extract fans, background ventilators, proposed airflow rates, combustion appliances, fire safety, room layout and the scope of the work. New homes and major alterations normally need a coordinated ventilation design rather than a single product decision.

Read how Positive Input Ventilation moves air through a home, compare our Nuaire Drimaster and wall-mounted PIV systems, or see the ventilation FAQs.

Important disclaimer

DryHome cannot approve Building Regulations compliance

DryHome Ventilation can explain the proposed PIV installation and provide product information, but we cannot approve a design or confirm that work complies with the Building Regulations. Approval and enforcement sit with the relevant council’s Building Control service. Always ask Building Control when a regulatory decision is required.

Want to discuss your property?

Use the online suitability check for an initial PIV recommendation, or contact us directly. Neither route replaces advice from Building Control where approval is required.

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