ADF Update Service - Issue 27

July 2010

Building Regulations are good news

The 2010 revisions to Part F of the Building Regulations covering ventilation, which are due to come into force in October, have been welcomed by leading ventilation manufacturer Titon.

Titon says Building Regulations are good news for:

Housebuilders and consumers
Ventilation industry and consumers
Window and door industry and consumers

Summary
Further information
Contact

Housebuilders and consumers

The revisions now make it legally binding to ensure that all fixed mechanical ventilation systems are commissioned and that the relevant Building Control Body is notified. Also, it has been made mandatory that air flow shall be measured on site – for all mechanical ventilation systems whether whole house systems or extract fans/cooker hoods. The regulations also ensure that the householder is given sufficient information about the system and its maintenance requirements to ensure correct operation.

As the housebuilding industry moves towards higher levels of the Code for Sustainable Homes, it is essential that ventilation systems are correctly installed to ensure they reach the energy efficiency levels they were designed to achieve while maintaining healthy indoor atmospheres. It is this common sense approach to best practice and accountability which has been underpinned by the revised regulations.

Domestic Ventilation Compliance Guide
Of particular note is the new Domestic Ventilation Compliance Guide, which lists in detail installation guidelines for all of the major ventilation systems including System 1 (extract fans and background (trickle) vents). The Guide contains checklists for declaration of the equipment, its performance and its commissioning which must be submitted for each installation address to the Building Control Body. Used in combination with the instructions supplied with all Titon ventilation products, the new compliance guidelines and checklists will ensure the installation is of a satisfactory standard in order to avoid subsequent problems either in maintenance or operation.

Air permeability
It has been recognised in the revisions that more and more houses are being built to be increasingly air tight, because of the drive to energy efficiency and sustainable, lower carbon homes. This “build tight, ventilate right” approach has been highlighted by the new guidance which has increased the amount of ventilation required in a more air tight house. Titon's range of products – both whole house systems and background ventilators – enable compliance regardless of the amount of ventilation required. For example, Titon's range of HRV Q Plus ultra-efficient whole house systems are designed for every size of property from an apartment up to an extremely large dwelling and trickle vents.

Installation and commissioning
In Titon's experience in supplying whole house ventilation systems problems have arisen when the system hasn't been installed or commissioned correctly – for example where too much flexible ducting has been used, the unit hasn't been wired correctly, sufficient space for access hasn't been allowed or it hasn't been commissioned at all. Titon expects the new regulations will go a long way to address these issues and more, helping householders get the very best out of their ventilation systems.

Control of ventilation
The regulations have also clarified that for all systems, door undercuts have to be: “10mm above the floor finish if the floor finish is fitted, or a 20mm undercut above the floorboards, or other surface, if the finish has not been fitted.” In addition, windows with less than 15 degrees of opening are not suitable for purge ventilation.

Ventilation industry and consumers

As the housebuilding industry moves towards higher levels of the Code for Sustainable Homes, it is essential that ventilation systems are correctly installed to ensure they reach the energy efficiency levels they were designed to achieve whilst maintaining healthy indoor atmospheres. It is this common sense approach to best practice and accountability which has been underpinned by the revised regulations.

Domestic Ventilation Compliance Guide
Of particular note is the new Domestic Ventilation Compliance Guide. Aimed at ensuring installed performance meets with the aims of improved energy efficiency and ensuring a healthy indoor atmosphere, the new document provides detailed guidelines relating to the installation and commissioning of all ventilation systems and helps raise awareness of mechanical systems which are becoming far more popular but where knowledge and experience is often lacking. The Guide also contains checklists for declaration of the equipment, its performance and its commissioning which must be submitted for each installation address to the Building Control Body. Used in combination with the instructions supplied with all Titon ventilation products, the new compliance guidelines and checklists will ensure the installation is of a satisfactory standard in order to avoid subsequent problems.

Air permeability
It has been recognised in the revisions that more and more houses are being built to achieve higher levels of airtightness and therefore the new guidance requires increased ventilation rates in more airtight dwellings, thus following the “build tight, ventilate right” approach. Titon's range of products – both whole house systems and background ventilators – enable compliance regardless of the amount of ventilation required. For example, Titon's range of HRV Q Plus ultra-efficient whole house systems are designed to ensure a suitable performance option is available for every size of property from a small apartment up to an extremely large dwelling.

Window and door industry and consumers

The revisions now make it legally binding to ensure that all ventilation systems and products including trickle vents, are commissioned and inspected and a full checklist and report must be submitted to Building Control. The regulations also ensure that the householder is given sufficient information about the ventilation products and their maintenance requirements to ensure correct operation.

As the housebuilding industry moves towards higher levels of the Code for Sustainable Homes, Titon believes that it is essential that ventilation systems are correctly installed to ensure they reach the energy efficiency levels they were designed to achieve, as well as the importance in understanding the overlap between trickle ventilators and the rest of the ventilation in the home. It is this common sense approach to best practice and accountability which has been underpinned by the revised regulations.

Air permeability
It has been recognised in the revisions that more and more houses are being built to be increasingly air tight, because of the drive to energy efficiency and sustainable, lower carbon homes. This “build tight, ventilate right” approach has been highlighted by the new guidance which has increased the amount of ventilation required in a more air tight house. Therefore, there are now two levels of total equivalent ventilator area for trickle vents required, depending on the air permeability of the dwelling. With this increased scrutiny, care will need to be taken to ensure the slot size is as per the manufacturer's instructions to achieve the EA claimed. Titon's background ventilators are available in a wide range of sizes for optimum compliance whatever the house design.

Control of ventilation
Although the need to fit trickle ventilators in replacement windows is not mandatory, it should be noted that the general guidance, which is applicable to both new build and existing dwelling states that: “Trickle ventilators are intended to be normally left open in occupied rooms or dwellings. A window with a night latch position is not recommended because of the difficulty of measuring the equivalent area, the greater likelihood of draughts and the potential increased security risk in some locations.” These locations are obviously more commonly found in replacement situations. As before, where the original windows were fitted with trickle ventilators, the replacement windows should also include them. Where they weren't, it is good practice to fit them – as the Glass and Glazing Federation (GGF) states in their guidance leaflet 'A Guide to trickle ventilators'.

The regulations have also clarified that for all systems, door undercuts have to be: “10mm above the floor finish if the floor finish is fitted, or a 20mm undercut above the floorboards, or other surface, if the finish has not been fitted.” In addition, windows with less than 15 degrees of opening are not suitable for purge ventilation.

Summary

In essence the overview of the changes are as follows (quoted from the Approved Document F 2010):

This edition of Approved Document F, Ventilation, replaces the 2006 edition and comes into force on 1 October 2010.
The following are the main changes to the legal requirements in the Building Regulations 2000 and the Building (Approved Inspectors etc) Regulations 2000, and in the technical guidance in Approved Document F.

Changes in the legal requirements

All fixed mechanical ventilation systems, where they can be tested and adjusted, shall be commissioned and a commissioning notice given to the Building Control Body.
For mechanical ventilation systems installed in new dwellings, air flow rates shall be measured on site and a notice given to the Building Control Body. This shall apply to intermittently-used extract fans and cooker hoods, as well as continuously running systems.
The owner shall be given sufficient information about the ventilation system and its maintenance requirements so that the ventilation system can be operated to provide adequate air flow.

Changes in the technical guidance

Ventilation provisions have been increased for dwellings with a design air permeability tighter than or equal to 5m³/(h.m²) at 50 Pa.
For passive stack ventilators, the stack diameter has been increased to 125mm for all room types. Use of passive stack ventilation in inner wet rooms has been clarified.
The guidance for ventilation when a kitchen or bathroom in an existing dwelling is refurbished has been clarified.
Reference is made to a new Domestic ventilation compliance guide for guidance on installing, inspecting, testing and commissioning ventilation systems in dwellings. Guidance in Appendices D and E of the 2006 edition of Approved Document F, on installing passive stack ventilators and fans in dwellings, can now be found in Section 2 of the new guide.

Please contact experts@partf.co.uk to discuss the revisions specific to you in more detail.