Building Regulations and Planning Permissions

Building Regulations: Approved Document B, Volume 1 for Glazing

Approved Document B, Volume 1, lays out the guides for fire safety in dwellings. For the purpose of this article, we will be focusing on the requirements that relate to architectural glazing and how we can help aid with a safe home design.

Dwelling refers to a place of residences such as a house or a flat, and therefore these regulations don’t apply to non-residential buildings such as schools or offices. Although the guidance is separated out many regulations and options overlap, so it is important for the document to be considered as a whole.

It is also important to note that although the fire safety requirements of the Building Regulations will likely be satisfied when following the guidance of Approved Document B, Volume 1, there are some exceptions.

This guidance is for common building situations and for more bespoke architectural designs there may be alternative methods that can be used to ensure the home complies, and regulations can differ depending on what purpose group the building comes under.

Recent amendments were made to Approved Document B in June 2022, so always check you are reading the most up-to-date version.

Fire Rated Glazing for Escape Routes

Sections 2 and 3 outline the regulations for means of escape in houses and flats respectively. For Section 2 which focuses on houses, all habitable rooms apart from the kitchen need either an opening that directly leads to a hall that leads to a final exit, or an emergency escape window or door.

Here the sizes of the window and opening configuration come into play as depending on the design of the room, the bespoke window design may need to allow for easy escape for the home’s occupants.

Homes with storeys that are more than 4.5m above the ground level must have a protected stairway and the fire resisting construction around the stairways must have a minimum fire rating of EI 30. Glazing in areas of fire resisting construction should be fixed shut and fire resisting in terms of integrity, but not insulation, with a minimum rating of E 30.

IQ’s fire rated glazing can reach up to EI 120, and so can easily meet the standard for Requirement B1 in Approved Document B, Volume 1. For more information check out our technical article on fire resistant glazing and ratings.

If glazed elements in fire resisting enclosures and doors can only meet the minimum integrity performance, then the amount of glazing that can be used is limited. These limitations depend on whether the enclosure forms part of a protected shaft and the provisions set out in regulations.

If both integrity and insulation performance can be met, which IQ’s fire rated glazing systems can, then there is no restriction in this document on the use or amount of glass.

There are also regulations outlined for replacement windows when working on existing dwellings. It is up to the architect to calculate the required size of the window, but IQ will assist with helping to ensure the window meets opening and performance requirements.

Essentially these regulations want to ensure that in the event of a fire, there are adequate means of escape and precautions put in place to ensure these fire escape routes limit the spread of fire, allowing time for the occupants to evacuate.

Fire Rated Glazing for Residential Lifts

Although fire rated glass lifts are more common in commercial projects, some dwellings may have residential lift systems installed, and for these, the lift must either be in the protected area with the stairway or be encased in a fire resisting lift shaft.

There are also regulations outlined for replacement windows when working on existing dwellings. It is up to the architect to calculate the required size of the window, but IQ will assist with helping to ensure the window meets opening and performance requirements.

Essentially these regulations want to ensure that in the event of a fire, there are adequate means of escape and precautions put in place to ensure these fire escape routes limit the spread of fire, allowing time for the occupants to evacuate.

Section 3 has the same aim for flats which similarly can be achieved through means such as protecting stairways, escape windows and doors of the lower floor flats and adequate means of fire detection and warning.

Fire Resistant Glazing to Prevent Internal Fire Spread

Options here help to inhibit the spread of fire over the internal linings of a building, looking and internal fire rated doors and using non-flammable materials. In this section of Approved Document B, Volume 1, ‘internal linings’ refers to any materials or products used in the lining of and partition, wall, ceiling, or other internal structures.

These linings must be able to adequately resist the spread of fire across their surface and if they do catch fire, a reasonable rate of heat release or fire growth.

In this requirement, a wall includes the internal surface of internal and external glazing systems but does not include doors (including door framed and any glazing within the door) or window frames and frames in which glazing is fitted.

Within this requirement ceilings also include any glazing (excluding any framing around rooflights), meaning that any glass specified for the wall or ceiling must comply with the regulations set out in Table 4.1 (classification of linings) of Approved Document B, Volume 2.

Fire Resistant Glazing to Prevent Fire Spread

These regulations ensure that the dwelling is built in such a way that in the event of a fire the premature collapse of a building is avoided, allowing occupants a reasonable amount of time to escape, fire separation is provided within buildings and between adjoining buildings, automatic fire suppression is provided where necessary and the unseen spread of fire and smoke in cavities is restricted.

This outlines regulations for using load bearing elements of structure that are able to withstand the effects of fire without loss of stability and using fire resisting construction elements to separate compartments of a building or adjoining buildings.

Stairs or shafts connecting compartments within a building should be protected to restrict the spread of fire between compartments. The term used for this is a ‘protected shaft’, which should be used for stairs, lifts, chutes, ducts and pipes.

An uninsulated glazed screen may be incorporated in the enclosure to a protected shaft between a stair and a lobby or corridor entered from the stair. The enclosure must conform to Diagram 7.2 and meet all of the following conditions:

• The standard of fire resistance required for the protected stairway is not more than REI 60.
• The glazed screen complies with the following: it achieves a minimum rating of E 30 or it complies with the guidance on limits on areas of uninsulated glazing in Appendix B, Table B5.
• The lobby or corridor is enclosed with fire resisting construction achieving a minimum rating of REI 30.

Regulation 38 & Appendices

Regulations 38: provide fire safety information to building owners

When you’re moving into a new build home or an existing dwelling, it is vital that the home's occupants are aware of information such as the fire escape routes, fire rated glazing and self-closing fire rated doors, the location of smoke detectors and smoke control systems.

Details should be provided to the homeowner on things like specifications of fire safety equipment including maintenance schedules.

Appendix A: Key Terms

Fire doorset is defined as a door or shutter that, together with its frame and furniture as installed in a building, is intended (when closed) to resist the spread of fire and/or gaseous products of combustion and meets specified performance criteria to those ends.

A fire doorset may have one or more leaves. The term includes a cover or other form of protection to an opening in a fire resisting wall or floor, or in a structure that surrounds a protected shaft.

A fire doorset is a complete door assembly, assembled on site or delivered as a completed assembly, consisting of the door frame, leaf or leaves, essential hardware, edge seals and glazing, and any integral side panels or fanlight panels in an associated door screen.

Appendix B: Performance of materials, products and structures

The fire resistance necessary for different circumstances is set out in the following tables.

• Table B3 gives the specific requirements for each element of structure.  
• Table B4 sets out the minimum periods of fire resistance for elements of structure.
• Table B5 sets out limitations on the use of uninsulated fire resisting glazed elements.

This table can all be found in Approved Document B, Volume 1, available on the UK government website.

Appendix C: Fire doorsets

All fire doorsets should be classified in accordance with BS EN 13501-2, tested to the relevant European method from the following.

• BS EN 1634-1.
• BS EN 1634-2.
• BS EN 1634-3.

Summary of Approved Document B, Volume 1 and Glazing

Fire rated glazing must meet a minimum of E 30, and in order to have no limitation on the amount of glazing that can be used it must achieve both integrity and insulation with a minimum fire rating of EI 30.

If a window is being used as an escape route, it must meet to requirement outlined in Requirement B1.

The glazing only forms part of the regulations and this document must be considered as a whole. We would always recommend involving and architect in your project as they are experts in building regulations and will be able to ensure that the dwelling design complies.

This is by no means a comprehensive guide but aims to outline some of the key fire safety considerations when specifying bespoke glazing for a residential project.

IQ are not experts in building regulations however it is vital that all of our employees have a strong understanding of the UK Building Regulations and how they relate to architectural glazing so we can work closely with architects to ensure that our glazing meets all the requirements.

To discuss fire rated glazing for your next project, contact the team today.

Further Reading

The following technical articles might also be useful if you are designing or specifying fire rated glazing.

Fire Rated Glazing

What is fire rated glazing and what are the design options?

Internal Glazing for Wine Cellars