Mhairi McDougall, Country Manager UK and Ireland at Dakea, reveals how roof windows can enhance an extension.
It is important to make sure that the balance of light and air within a new extension is exactly right, as otherwise the space risks being cold, dark, and stuffy. Roof windows are a great way to achieve that balance, as they increase the amount of daylight and fresh air and, if properly designed, will make the extension a more pleasant place to be, both in the depths of winter and in the heat of summer.
Natural light is one of the most obvious benefits of installing roof windows, as they make sure that the new living area is as bright as possible, without the need to use artificial light – providing health benefits and reduced energy bills to your clients. A good way to see whether an area will get enough light is to make sure that the amount of roof windowpane visible is equal to at least 10 per cent of the floor area. Getting this formula right will not only provide residents with the advantages of increased exposure to daylight, such as being more productive, happier, and healthier, but natural light also helps to reduce mould and mildew growth.
After light, it is fair to say that the next main benefit of a roof window is its ability to improve a building’s air flow. In fact, it’s advised that at least half the air inside a home is refreshed every hour, as fresh air not only stops a space feeling stuffy and unpleasant, but it also boosts immune systems as well as improve concentration and energy levels. Installing a roof window with a ventilation valve is a great way to ensure a constant supply of fresh air into an extension.
While you want air to come in, there are a few things best left outside – such as rainwater. Windows on a sloped surface get hit by more rainwater than vertical windows, as the shape of the roof will funnel water over its surface. This means that it is vitally important to check the roof window’s water tightness to determine whether it will be able to withstand what the elements are going to throw at it.
One of the other key roles that a roof window plays when it comes to the comfort of the home’s users is its ability to keep them cool when it is hot and warm when it is cold. The effectiveness of a window to achieve this can be determined by its thermal transmittance properties, which shows how much heat goes through the window. A low thermal transmittance value is therefore best, as it will stop cold or hot air from moving into the house, both making it a more pleasant environment, and cutting down on energy bills.
There are some key design features to look for which can improve the thermal transmittance and energy efficiency of a window. Choose a roof window that uses krypton gas, instead of argon, to fill the space between the panes. The former conducts much less heat and therefore is better at stopping the transference of thermal energy from outdoors to indoors. In addition, triple pane windows with an additional pane and two gas filled cavity spaces provides a much better standard of insulation.
Thermal transmittance goes together with air permeability, as there is no point installing energy efficient glass if the window fitting itself is not airtight. Windows can be tested for their ability to avoid unwanted air leakages, a test which places them in one of four classes depending on how well (or poorly) it did, with a higher class indicating a higher level of airtightness.
As we can see, there are a lot of different issues and design aspects that go into choosing the right roof window. Working with a supplier who understands all these factors is essential, as they will be able to advise on everything from the type of glass or frame material to when it can be delivered as well as what certifications and test data are most important.
For further information on the Dakea range of roof windows visit dakea.co.uk/products/roof-windows/
Dakea recently launched its Trade Matters campaign to help installers with the everyday business challenges they face, such as managing their finances or getting their name out there in the local area. You can find out more about the campaigns and even download a selection of free tools designed to help those in the trade industry at tradematters.co.uk