Should I insulate my home and how much will it cost?
If you want to make your home more energy efficient, one of the best and most cost-efficient ways to do it is to upgrade your current insulation. Every home has a certain level of insulation, but improving areas like the loft, walls and windows can make a big difference. So if you’re wondering if you should insulate your home and how much it will cost, we explain more below.
Roof insulation
It is estimated that about 25% of the heat generated by your boiler escapes through the roof (compared to 35% through walls, gaps and windows), so insulating your loft or attic will improve energy efficiency and save you money on energy bills in the long run.
Unused loft spaces are relatively easy to insulate by laying mineral wool in-between and over the joists. Even if you already have some insulation in place, adding to it so you have a thickness of at least 270mm will reduce heat loss.
Avoid blocking the eaves and perhaps insulate the cold water tanks so they do not freeze. And for a more natural option, sheep’s wool offers a sustainable alternative.
Converted lofts will likely already have insulation in the floor, but it can still be added to the roof, although this takes more work. In terms of cost, the Energy Saving Trust estimate an average semi-detached house will require you to spend £300-£400. Detached houses are £400-£500, while terraces are cheaper at £200-£300. However, due to the impacts of Covid, these estimates can vary.
Wall insulation
The type of insulation you need for the walls depends on how old the property is and the type of walls you have in place.
Sold walls (single leaf)
Built pre-1919 and made from brick or stone. You can insulate solid walls inside or out, although it can cost quite a bit of money either way. For period homes you’ll have to consider how to maintain the original aesthetic and weigh up the pros and cons of internal wall insulation (IWI) and external wall insulation (EWI).
Cavity walls
There are two categories here: uninsulated walls which were built between 1920-1975, and insulated walls built after this period. Both will be made from either brick or block work. Retrofitting cavity wall insulation will always have some effect on the ventilation between masonry leafs, so it is best done by professionals who can also assess if it is the right type of insulation based on the local climate.
Costs vary according to the type of property you own. The Energy Saving Trust estimate you will pay around £500-£600 to insulate cavity walls in a semi-detached and £700-£800 for a detached property. Insulating solid walls will cost more money, with the price estimated at around £7,000-£8,000 for internal walls and £13,000-£14,000 for external walls, based on a typical semi-detached house. Again, due to the impacts of Covid, these estimates can vary.
Window insulation
More heat is lost through gaps around window frames than through the glass panes themselves, so if the windows haven’t been upgraded in a while it is a good idea to consider installing replacements. Even if you live in a period home, if you have single glazing windows it will help to replace them with double or triple glazing.
If you already have enhanced glazing in place, in most cases you should be able to hire a professional to carry out repairs, rather than installing completely new windows. This is true of both modern uPVC varieties and older styles made from timber. Secondary glazing usually costs even less than double glazing and also has less of an environmental impact. Repairs are generally a more cost-effective option compared to a full upgrade across the entire house. Although, secondary glazing is considered a more temporary solution rather than a long term one.
You can also make simple changes inside the home by using thicker sets of curtains or using well-fitting shutters, as they will help reduce heat loss. The long-term benefit of investing in repairs or upgrading will pay off in the long run as you should see lower energy bills, so the alterations will pay for itself in the end.
The cost of double glazing can be anything from £500 to £3,200 per window, depending on the type of glazing you install. Alternatively, secondary glazing can be as much as 50% cheaper per window.
Are there any grants for home insulation?
The government is making a big push to make homes greener in the UK, which means you can make an application to receive a Green Homes Grant to insulate your home.
As long as you are carrying out primary work such as adding insulation or low-carbon heating (heat pumps etc.), you can apply for financial assistance for installing things like double glazing and draught proofing.
People on low income can claim up to 100% of costs up to £10,000. In other cases, you will be able to claim up to £5,000.
Make the right home improvements
If you are in a position to build your own home, or can’t afford to move to a larger property and are considering adding an extension, TEREYN Architects can help you plan, design and manage the entire project. We’re located in Cambridge and have years of experience working on retrofit/refurbishment projects, so to find out more and to arrange free consultation, get in touch today on 07984 760 920, send us a message here or email us at info@tereynarchitects.com and we’ll get right back to you.
