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Green Homes Grant - replacing windows and doors


Green Homes Grant - replacing windows and doors

With the Government’s recent announcement about the Green Homes Grant, from September homeowners should be able to apply online for up to £5,000 of vouchers for energy-efficient home improvements. (*At the time of writing it is unclear whether there will be an assessment needed to get the vouchers so look out for further announcements.)

The vouchers should cover 2/3 of the cost of any eligible energy-saving improvement and it is expected these will include double glazing as well as insulation, boilers and more. It is thought the lowest income household won’t pay anything and could get up to £10,000 of vouchers.

If this is the incentive you need to think about replacing your windows and doors, now is a good time to start doing some homework prior to Autumn. To be eligible for a voucher, in September when the scheme is due to launch; you will need to complete an online application for a recommended home improvement, get a quote from a recommended supplier (no details of these yet) and have the quote approved before going ahead with the work.  This is not only great news for homeowners but will help the UK meet its target for 2050 of zero carbon emissions and create tens of thousands of new jobs.

Choosing a window style
This should be in keeping with your property externally and your own interior design taste might also play a part. Do you prefer minimalist, simple styles or intricately designed frames?  If you are only going to replace existing windows and doors (not making larger or new openings), a window specialist who is FENSA registered will be able to advise you on what styles will suit your home and décor.

UPVC is the most commonly used window frame material, being typically three times cheaper than a traditional wooden frame. It is also recyclable, durable, easy to maintain and the most energy efficient type of frame.  Frames are available in varying colours, white to the latest graphite and black trends. 

Aluminium frames are equally durable and can be manufactured in slimmer, lighter profiles because of their strength.  They too come in many colours and offer a sleek, modern look. Cost wise they will be more expensive than UPVC.

Wooden/timber frames are a greener alternative and fit well in period or traditional style properties.  They are likely to be a more expensive option and will need maintaining, however they should last a long time if looked after.

Consider how each window will be used.  Do they all need to be openable or do you have room for a fixed pane feature/stained glass window?  (There are certain requirements under the building regulations where windows must be of a certain size and have a certain sized opening, such as where they are used for means of escape in the event of a fire and we will be happy to discuss this with you.)

Would it be useful to include skylights to existing rooms to provide more natural light?  Would bi-folds look more in keeping with your modern home and help to bring your indoor and outdoor living spaces together?  Walking through your home will give you a better idea of how you could make improvements.

Can be the worst culprit when it comes to heat escaping from your home so new glazing needs to comply with the building regulations U-values. (The amount of heat that can pass through the glass.)

Most windows use double glazing however if you are keen to block out outside noise or have a particularly cold room in your home you could consider triple glazing those rooms only.  Triple glazed windows have a third pane of glass with either a gas between the panes to prevent heat loss and low-E glass to reflect sunlight inside. The cost per window will be more expensive but may be worth it in the long run.

There also requirements for special types of safety glass in certain areas, such as in low level windows and glazed doors where there is a possibility that someone could fall into them and injure themselves.

A new double-glazed window could cost up to £3,000 so to replace a whole house of windows is a big financial outlay.  There are however ways you can look at costs, UPVC windows are a lot cheaper than hardwood sash windows and aluminium windows whilst expensive will stand the test of time better than UPVC.

Similarly, the more glass or detailing a new door has the more expensive it is likely to be however you shouldn’t compromise on cost if every time you open your door you wish you’d spent that little bit extra! 

Adding patio doors
Whilst adding new doors or creating new window openings won’t come under the Government scheme, it is worth mentioning in this blog, as open plan living and extending your living space into your garden continues to be a popular trend. By adding glazed access doors, you also bring in more natural light to your home.

There are various types of doors to choose from, French doors, sliding doors or bi-fold doors.  Again, you should consider what style would suit your property best.

French doors are a great addition to a modern or period home and are usually made of hard or softwood. Softwood being less expensive but requiring more maintenance.

Sliding patio doors now come in modern, sleek designs and you have the option to make them into ‘pocket doors’ which cleverly fit into a wall compartment when open.  Usually made of aluminium or UPVC.

Bi-fold doors are easy to maintain and fit well in a modern home. They usually run on tracks within the floor of your house and concertina-up when fully open.  You therefore need to make sure you have sufficient space at one end of the structural opening for the doors to sit when fully open.

Will I need planning permission?

If you are replacing like-for-like windows you are unlikely to need planning permission (unless you live in a listed building or conservation area when different rules apply) but we would still advise you to check with your local planning department and the planning portal interactive house will also help.  If you are creating a new opening in a wall or enlarging a window to create a doorway you will again need to check with your local planning department as this is an aesthetic change to your property.

When can I use a FENSA approved installer?
If the replacement windows and doors are being fitted by a FENSA approved installer you do not need to let building control know as they will inform us on your behalf. FENSA is a government authorised scheme whereby each registered installer can self-certify that their work complies with the building regulations and the glazing is safe and energy efficient.

When do I need to notify building control?
If you are making new openings, changing the size or shape of an opening for example to install bi-fold or French doors, or your builder is fitting the frames for you and is not FENSA registered, you will need to make a building regulations application before you start work.  Once the work has been carried out we would come out to check the structural integrity and that the glazing meets glazing and safety standards. (We may also need you to provide structural calculations for larger new openings.)

You will find a more in-depth chapter on replacing and adding windows in our online Guide to Extending your Home here.  If you would like to talk to us about your project, please get in touch on 0330 0249355 or email

* Update October 2020

Improvements must be carried out by 31 March 2021. Visit the Government's Green Homes Grant website pages here to find out about eligibility, how much you can get, what improvements are included in the deal and how to apply.


Categories: Blog