New information outlines the prospects of replacing your property's windows with funding from the Green Homes Grants. 

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With details about the scope of the Government's Green Home Grant slowly feeding through, – the Glass and Glazing Federation’s consumer advice website – has firmed up some specific information relating to the replacement of single glazing with double or triple glazing, or the addition of secondary glazing. 

This includes some stringent restrictions on who can apply for vouchers to partially fund the replacement of single glazing. 

Read more: The Green Homes Grant scheme: how does it work?

Can I apply for vouchers to replace single glazing in my property?

For those who had pinned their hopes on the Green Homes Grant to help to replace single glazing in a property, the latest news of the scheme makes for important reading. The information supplied to Grand Designs magazine outlines that the energy-saving measures covered by the grant will be separated into two categories: primary measures and secondary measures. 

The Green Homes Grants will give homeowners, including owner-occupiers and social/private landlords, vouchers of up to £5000 to cover two-thirds of the cost of installing one or more of solid wall, under-floor, cavity wall or roof insulation, air source or ground source heat pump or solar thermal, which all count as primary measures. This increases to grants of up to £10,000 for those in receipt of certain Government benefits

If your home already has these primary insulation measures in place, you can use the grant to top up or extend these elements, but not to replace them fully. If you do opt to claim funding for a primary measure through the Green Homes Grant, then you are eligible to apply for any secondary measures, including the replacement of single glazing.

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However, it is worth noting that you cannot receive more funding for secondary measures than you do for one of the primary measures. This means if you claim £1,000 for insulation or a heat pump installation, you'll only be able to claim up to £1,000 for replacing windows in your property. 

Do I have to replace glazing with a certain type of window?

Those eligible to undertake replacement glazing work will be included on a Government provided-list, made up of TrustMark registered businesses, including those approved via the Microgeneration Scheme (MCS).

The scheme does not outline any restrictions on options for replacing glazing other than it must be applied to homes with single glazing – meaning that if a homeowner wanted to replace a single-glazed wooden sash window with a new triple-glazed sash window, that would be covered by the scheme, despite the costs differences compared to a standard u-PVC window, as long as the cost is within the £5,000 voucher and does not exceed the cost of the primary measure. 

Depending on the window type, size, frame materials and specification replacing the single glazed window, the average cost (based on an average 1200 x 900 casement u-PVC window) would be approximately £300-£400 for the whole window (glass, frame, seals, hardware) etc, while a replacement sash window should be expected to cost between £1000-1500. 

There could be other costs to consider such as extra labour costs if it’s a larger window opening or perhaps in an awkward position. Upper floor windows also are usually more expensive to replace.

Can I replace faulty double glazing under the scheme?

No, the Green Homes Grant only covers the replacement of single glazing. However, as 24% of heat can leave the house through inefficient windows, it's worth considering replacing leaky windows or double glazing that dates to before 2002 effiency guidelines outside of the Green Homes Grant to ensure your home is as energy efficient as possible. 

The scheme does not cover orangeries or conservatories. 

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