Contact

 

Energy conservation - windows and doors

Replacing your windows and doors

The type of glazing in your doors and windows can reduce the heat loss from your property.  This in turn will reduce the amount of time your central heating boiler will need to run and will therefore reduce the carbon dioxide emissions from your building into the atmosphere.  It is this carbon dioxide that is contributing to global warming.

This is the reason that the Government decided to make replacement windows and glazed doors subject to Building Regulations from the 1 April 2002.

Meeting regulations

Any replacement windows and substantially glazed doors will therefore need to meet the Building Regulation standards for heat loss.  This is normally achieved by fitting special glass in double glazing with an argon gas between the panes.  The heat loss from the glass is measured by what is known as a 'U' value.  This is the maximum energy that can be lost, measured in energy watts for every square metre of glass and for every temperature difference inside and outside your building.

The current value is 2.0  watts per metre squared per degree Kelvin for the glass and frame.  This is also achieved by a window frame with an energy rating of Band E.  The glass panel should have U value in the centre of the pane of 1.2 W/m2/K.

Other issues to consider with replacement windows

The two important issues to also consider when having replacement windows are fire escape windows and ventilation. 

Fire escape windows:  It is a Building Regulation requirement that all windows at first floor level have openings large enough and positioned so that people can be rescued from a ladder in the case of a fire.  Additionally certain windows in rooms that do not have a direct escape route without going through another room require escape windows.  When replacing windows it is a legal requirement that these escape windows are maintained.

In some circumstances, existing first floor window openings may have  been installed before escape windows were a legal requirement.  In some cases, these windows may still be large enough to escape through.  The Building Regulations require these windows not to be made worse, so your replacement windows should also be escape windows.

If your existing house has no escape windows we strongly recommend you consider escape windows for your replacements to improve your safety and the safety of your family.

Ventilation: The existing ventilation provided by your windows should not be made worse by any replacements.  In some cases this can affect the combustion air provided to heat producing appliances such as fires or boilers. 

It normally affects appliances known as 'open flued' appliances, which take their combustion air from within the room.  One scenario is that existing windows may be sufficiently 'leaky' to allow sufficient air to enter the building, which may permit the combustion appliance to operate safely.

By installing modern sealed windows you may reduce the ventilation and affect the operation of the appliance.  If you are having new windows installed we strongly recommend that you employ a CORGI registered gas installer to check any open flued appliances for safe operation once the windows are fitted.

I want to replace my windows and doors.  What does this mean to me?

When introducing this requirement the Government decided that certain window installers could self-certify their window installations as complying with the Building Regulations avoiding the need to apply for approval from  the local authority.

The current self-certifying schemes are applicable  to installers registered with either FENSA (Fenestration Self-Assessment Scheme), British Standards Institute (BSI), or Certass Limited.  These self-certifying schemes may be extended so check whether your installer is exempt for applying to the local authority for approval by viewing the current schemes in force at Communities and Local Government website under building regulations.  Alternatively you can call Building Control for advice.  We recommend that you check with the CPS scheme that your installer is registered.

if your window installer is registered with a current scheme they can install your windows and doors without any inspection from the local authority.  They must supply you with a certificate and their Competent Persons Scheme will supply your details to a database to be held by the local authority so that your installation is recorded.  You need to keep your certificate safe in case you decide to sell your house.  This will be proof that you have had the work done legally.

For DIY installers a Building Regulation Application must be submitted to the local authority normally in the form of a Building Notice.  You will pay a fee to the Council and a Building Control Officer will visit and check that the installation complies with the regulations.  The council will write to you confirming that the work complies with the relevant requirements.

Energy conservation

Global warming and rising energy costs affect us all and the Building Regulations, which came into force in April 2006, will affect homeowners when undertaking building and repair work.

The aim of the regulations is to improve the energy efficiency of existing houses when alterations are made to the walls and roofs.  The energy efficiency of a house built before 2002 is about half that of a house build after 2002.  This means that heating and lighting costs are much higher for older houses and they therefore produce more carbon dioxide. which is damaging our environment.  About 95 per cent of our houses are built before 2002.

What work is affected?

Building Regulations have applied to replacement windows since 2002 and the Government now wants to improve walls and roofs when they are being altered.  This could be when you are building an extension, converting a building such as a barn into a house, making alterations internally or when renovating your house.

These new regulations represent a significant change, as they will require you to improve the insulation of your roof, wall or floor if it is to be replaced or renovated.

This means building work such as the replacement of external render or tile hanging to a wall, extensive re-plastering internally or having new roof tiles or slates may require extra insulation to be added at the same time.  The Government call this work the alteration of a 'Thermal Element'.

Examples or works that require the submission of a Building Regulation application
  • Renewal of pitched or flat roof coverings - for example re-tiling, re-slating or re-felting of roofs.
  • Renewal or replacement of ceilings under a roof space or flat roof (with or without the renewal of the supporting structure).
  • Renewal of cladding to external walls or dormer cheeks.
  • Renewal of a finish or cladding to an external wall area or elevation (render or other cladding) or applying a finish or cladding for the first time.
  • Re-building an external wall including the outer leaf of brickwork or stonework only.
  • Renewal of internal wall plaster or plasterboard to an external wall or where plaster or plasterboard is being applied for the first time, for example re-plastering or dry lining floor deck.
  • Renovation or replacement of a solid or suspended floor, involving the replacement of a screed or a timber floor deck .
How much insulation should be provided?

The regulations expect the cost of improving the insulation of thermal elements to be recovered within 15 years through reducing energy costs.

If the cost of upgrading the insulation to modern standards cannot be saved within 15 years or less or they are not technically feasible, the element should be upgraded to the best standard possible at a cost that can be recovered within 15 years.

How is the cost calculated?

In some cases it may be possible to agree what is reasonable with the Building Control officer.  However for more complicated situations you may need to employ a suitably qualified person to advise of technical and economic feasibility.  Building Control may ask you to provide this information depending on the circumstances.

Emergency repairs

In certain situations it may be necessary to carry out emergency repairs to thermal elements.  For example if your roof is damaged in a storm.  If this situation arises a Building Notice must be submitted at the earliest opportunity after commencement; please note that repairs must comply with the new regulations.

Changing the energy status of the building

Changing the energy status of the Building may also require upgrading of the insulation.  This can occur when converting a previously unheated or cooled space into one that is heated, for example the conversion of a domestic garage into a living space.  When such a change occurs, the existing envelope of the building should be upgraded to reduce the amount of energy needed to heat or cool this space.