Windows and Doors and Building Regulations (England only)

This brief guide provides useful information for specifying windows and doors to provide compliance with Building Regulations. For full detailed information, please go to where all the Approved Documents are free to download. Before ordering Windows and Doors, it is essential to check with Qualified Building Experts that the proposed installation will conform with current regulations. Building Regulations in Scotland and Wales are very similar to those in England, but they are a responsibility of the Devolved Parliaments.

The Documents relating to the installation of Windows and Doors are:

Structure: Approved Document A – 1 September 2013 Statutory guidance
Fire safety: Approved Document B – 7 December 2010 Statutory guidance
Resistance to sound: Approved Document E – 4 March 2015 Statutory guidance
Ventilation: Approved Document F – 1 December 2010 Statutory guidance
Protection from falling, collision and impact: Approved Document K – 3 January 2013 Statutory guidance
Conservation of fuel and power: Approved Document L – 13 October 2017 Statutory guidance
Access to and use of buildings: Approved Document M – 9 March 2016 Statutory guidance
Security in dwellings: Approved Document Q

• Structure: Approved Document A – All our windows and doors should be considered non-load bearing. Exceptions are where very light-weight roof constructions are used in Conservatories and Porches.

• Fire safety: Approved Document B – Gemini does not supply any Fire-Rated Doors or Windows. Fire doors and windows are commonly required between a dwelling and a garage, or in buildings such as blocks of flats, where doors and windows open onto communal internal areas.

• Resistance to sound: Approved Document E – Generally there is no requirement for sound insulation to the exterior of a dwelling. However, should external noise be a factor in the selection of Windows and Doors, then you should consider installing “Acoustic Laminated Glazing”.

• Ventilation: Approved Document F – For replacement windows, the rules state that the new installation should not be worse that the original windows.  For New Build properties, then the required amount of ventilation can be found in Tables shown below.

Table 5.2a System 1 – Background ventilators and intermittent extract fans (for additional info see Table 5.3 and worked examples C1 and C5 in Appendix C) Background ventilators (follow Steps 1 to 3 below)

Step 1: Determine the total equivalent ventilator area – See Table A below for a dwelling with any design air permeability. As an alternative, the guidance in Table B below may be followed for a dwelling designed to an air permeability leakier than (>) 5 m3/(h.m2) at 50 Pa which recommends less ventilation provisions, but see the cautionary advice in paragraph 5.10.

Step 2: Follow (i) or (ii) as appropriate depending on the number of storeys:
(i) For multi-storey dwellings, and single-storey dwellings more than four storeys above ground level:

• Use the total equivalent ventilator area from Step 1.
(ii) For single-storey dwellings up to and including the fourth storey above ground level:

Add a further 10000 mm2 to the total equivalent ventilator area from Step 1, preferably shared between several rooms.

Step 3: For dwellings which have a single exposed facade, or at least 70% of the equivalent area is designed to be on the same facade, cross-ventilation is not possible, or is limited, and additional ventilation provisions are recommended. In this case background ventilators should be located at both high and low positions in the facade to provide enhanced single-sided ventilation. The total equivalent area as described in Steps 1 and 2 above should be provided at the high position (typically 1.7 m above floor level) for all dwelling types and all storey heights. In addition, ventilators having the same total equivalent area should be provided at least 1.0 m below the high ventilators as shown in Diagram 2b. Single-sided ventilation is most effective if the dwelling is designed so that the habitable rooms are on the exposed facade, and these rooms are no greater than 6 m in depth.

• Protection from falling, collision and impact: Approved Document K – There are a number of sections which must be followed regardless of whether the installation property is a new build or existing construction. The sections of the Approved Document relating to windows and doors are:

Section 5: Protection against impact with glazing
Section 6: Protection from collision with open windows etc.
Section 7: Manifestation of glazing
Section 8: Safe opening and closing of windows etc.
Section 9: Safe access for cleaning windows etc.
Section 10: Protection against impact from and trapping by doors

The most common requirement is for safety glazing where there is a risk of human impact. The graphic below shows examples where safety glass is mandatory.

• Conservation of fuel and power: Approved Document L – There are 4 distinct sections to Part L of the Building Regulations:

• L1A – New Dwellings
• L1B – Exiting Dwellings
• L2A – New Buildings other than Dwellings
• L2B – Existing Buildings other than Dwellings

Under L1A – Windows and doors must have a maximum u-value of 2.0 W/m 2K.

Builders usually require windows and doors with better performance than this in order to achieve the Target Energy Performance of the whole building.

Under L2A – Windows must achieve the standards as shown in the table below

All windows and doors supplied by Gemini Windows comply with the requirements of Approved Document L2A.

• Access to and use of buildings: Approved Document M – The main entrance door of dwellings should be fitted with a threshold capable of allowing Wheelchair access. Gemini Windows supply doors with a standard threshold or when specified a Document M compliant low aluminium threshold. When specifiying a low aluminium threshold, it is important to ensure the door has protection from driving rain such as a canopy above the door, as doors with accessible thresholds are not storm-proof.

• Security in dwellings: Approved Document Q – This applies only to new dwellings, whether formed by new build or material change of use. Replacement windows and doors or those fitted into extensions or buildings other than dwellings do not need to comply with Approved Document Q.

The requirements apply to all “easily accessible” windows and doors. “Easily accessible” is defined as “any window or doorway, any part of which is within 2m vertically of an accessible level surface such as the ground or basement level, or an access balcony, or a window which is within 2m vertically of a flat or sloping roof (with a pitch of less than 30 degrees) that is within 3.5m of ground level.

Any new dwelling where plans have been approved since 1st October 2015 will need to comply. After the 1st October 2016, all properties will need to comply regardless of when plans were approved.

Windows and Doors must be manufactured to a design that has been shown by test to meet the security requirements of PAS24:2012 (other standards are included).

Main entrance doors should be fitted with viewers and chains. Viewers can be omitted if there is an alternative and chains can be omitted in circumstances where entry needs to be gained in certain circumstances such as sheltered housing.

Where doorsets, coupled side panels and windows adjacent to door-sets contain glass, each glazed area shall include at least one pane of 6.8mm laminated glass. Where windows contain glass and non-key unlocking hardware, each glazed area shall include at least one pane of 6.8mm laminated glass.