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Things to consider before you buy

New windows and doors will create a better internal atmosphere. However, there are a few conditions you should be aware of so that you can get the most out of what is likely to be a significant investment.

Measure the windows and doors correctly

Consider the tolerances before you calculate the measurements of the window frame. We recommend that you leave 10-12 mm for tolerances around the window and they should be taken from the structural measurements.

If you are going to replace windows in an older property do not just take the measurements of one window even though all the other windows may appear identical. This is not always the case. To be certain take measurements for all the windows.


Questions to ask before you install Rationel windows

Is the window able to open without the roof being in the way?

Is there adequate space for the fresh air vent in the side frame? Is it covered by a lighting panel, tiles or something similar.

How would the new window fit in relation to, for example, the height of a kitchen work top?

Does the bottom section of the new door fit with the floor height inside and outside? 

2. Think of both appearance and your view

Be careful that your view is not obstructed when looking out try to avoid placing bars and posts at eye level. 

3.  Large glass panels and the sun

Large areas of glass will let in a lot of daylight. High levels of daylight will brighten your mood and will reduce your heating bills.

In the summer you will be exposed if you have a typical urban house without eaves. In this case the house will be totally exposed to the sun making it feel very hot inside.

You should refer to the glass section on this website and decide your own requirements for specialist glass, in this case solar glass would be necessary. Otherwise it might be worth considering placing the larger glass facades toward the north or east.

Once Rationel windows are installed in your home

1. Let in some fresh air!

New windows are sealed.

It is up to you how and when you air your house. It is a myth that it is expensive and energy inefficient to keep a house ventilated. You just need to make sure you do it the right way.

Open a window or a door all the way to ideally allow a draft. By doing this you will exchange the warm moist air inside with the cold and dry air outside in less than 10 minutes. In such a short time there will be no cooling of the room's larger items such as furniture, walls and floors etc. and the loss of energy will be so small that it will be hardly noticeable.

2. Wash the whole window - not just the surface

We recommend you open the windows a couple of times a year to wash and clear all window frames. Only use water with a small amount of cleaning agent. It is particularly important to remove spider webs and any debris that inevitably gathers in corners that obstruct the automatic drainage and necessary ventilation paths. Blockages can cause dampness and rot the wood.

It is this maintenance that can extend the life of your windows considerably.

3. All windows and doors require maintenance

To ensure the longevity of your windows and doors maintenance is necessary.

If you have chosen ALDUS wood/aluminium windows you only need to wash the windows and frames a couple of times a year or when you are cleaning the windows. In order to keep the aluminium frame shiny, we suggest that you polish it with wax such as car polish, say once a year. If you give the movable hinge parts a drop of oil once in a while you will have windows that look new and function for many years.

If you have chosen DOMUS wood windows they should be looked after as ALDUS but the windows will eventually require repainting or staining.

Keep an eye out for gaps in the outside surface treatment on a regular basis, especially at the south and west-facing facades. In these areas the sun's UV-rays are hardest on the timber and once you have gaps in the paint dampness will start to set in and the deterioration of the wood will have begun.

It's a good idea to inspect the windows once a year and make good the surface with a brush and paint where needed. The wood humidity should be between 15 and 18 percent and the air temperature should be approximately 15 degrees when you do the work. Avoid painting in damp conditions.






A few things to consider

  • Rationel Windows Ltd.
  • 7 Avonbury Business Park
  • Bicester, OX26 2UA
  • United Kingdom
  • Phone +44 1869 248 181
  • Legal disclaimer