Install new windows – instructions step by step

Are you standing in front of your windows and feel the cold drafts because your window is not properly sealed? Are you annoyed by the street noise, which despite closed windows penetrates into your apartment? Have you built a new house and are now looking for the right windows? Or do you just want to save expensive craftsmanship costs? Just build your own windows and become a home improvement! With our following tips and tricks, window installation is easier to do than you suspect at first glance.

Choose the right frame material

Table of Contents

  • 1 Choose the right frame material
  • 2 Determine the right type of glazing
  • 3 The different types of seals
  • 4 Installing the window: instructions, step by step
  • 5 conclusion

Before you can start installing your new window, you have to choose a suitable window model. There are different materials and colors as well as different frames, sashes and closing mechanisms. While color plays no role in functionality, frame material, glazing and gasket all contribute significantly to energy consumption. So before you install a window, you should decide which materials you want to combine.
To give you an overview of the variety of window frames, we present below the most important and common frames. The acquisition costs differ only minimally in comparison, the maintenance costs and the maintenance costs vary considerably.

Plastic windows

Plastic windows are made of PVC. Unlike other windows, they have high weather resistance. While the prices for the frames within the plastics segment often differ only minimally, the favorable care due to the lower expenditure on cleaning and material maintenance is of particular importance here. Plastic windows are less sensitive compared to other frame types and therefore longer lasting.

Aluminum windows

Windows made of aluminum are light and yet stable, which is an advantage if you want to install windows yourself. Even large formats are possible. Individual window solutions can be implemented relatively inexpensively with aluminum frames unlike the other frames. The maintenance effort for aluminum windows is rather low.

Wooden window

Wooden windows are natural products. By low production costs, they are relatively cheaper. By simply recycling, they are also more environmentally friendly. Another advantage when installing wood is the durability in fires: While plastic windows melt in the event of a fire, treated frames and wings of the wooden windows last longer in the masonry. Also, wood windows provide a more pleasing feel and radiate a soothing warmth, like no other material. However, the maintenance effort compared to the other materials is higher, because the frame and casement require regular and particularly intensive care.
All window frames have a high closing density, making them absolutely suitable for easy installation. For Passive Houses special frames are made that are more expensive than other windows.

Determine the right type of glazing

The glazing also contributes significantly to the energy consumption and thus to the efficiency of the built-in windows.

Single glazing

Simple glazing is no longer available on modern windows, as the energy balance is so poor that installation is not worthwhile. You should therefore basically not use single glazing.


Double glazing is particularly useful in renovations when the rest of the house has a normal energy balance. In new buildings very high standards are often complied with, that even a double glazing is no longer sufficient.

Triple glazing

Triple glazing is worthwhile if you renovate the entire house in a more energy-efficient way.In addition to the energy balance of the disc and the insulation of the house plays a major role. In this regard, the triple-glazing has decisive advantages: The sound insulation is significantly better and also the burglar resistance increases. They are about 50% heavier due to the third disc and thus make the work more difficult if they want to install the window on their own. But the effort is worth it: You have windows later, which let almost no cold through.

Multiple glazing

Multiple glazing must be used in passive houses , so that absolutely no cold from the outside penetrates through the panes. Seal and frame are also custom made. Multiple glazing in normal houses pay less. In this case, you should rather resort to a triple glazing and then seal them well. This way money can be saved in a simple way.

The glazing style of your window goes hand in hand with energy efficiency. Further information on this topic is available from the responsible Federal Ministry at .

The different types of seals

In order for your windows to withstand wind and weather, they must be well sealed. The gasket is usually selected to be complementary to the pane, so that the glazing together with the gasket absolutely seals the window. Depending on the frame type and glazing, the manufacturer will recommend one of the following types of gasket, if this is not already included in the scope of delivery:

  • Sash seals
  • Window lip seals
  • Glazing seals
  • Means seals
  • Rollover seals
  • Adhesive seals

Modern gaskets should always be waterproof and prevent moisture from entering.

Installing the window: instructions, step by step


  1. Choose the frame material to suit your needs: aluminum for exceptional sizes, wooden windows for good energy balance, plastic windows for easy maintenance.
  2. The type of glazing contributes to the energy balance: double glazing for the renovated house, triple glazing for the new building and multiple glazing only for passive houses in order to keep costs down.
  3. The seals are often automatically adjusted so that the energy efficiency of the window is optimally designed.

Last preparations

If you have determined the size of your window by measuring the old window or following the plan when installing it, you can start to install the new windows. We recommend that you have the following – necessary tools, machines and materials at hand:

  • Tools: folding rule, spirit level, protractor, craft knife, cartridge gun, hammer, chisel, screwdriver, joint smoother and possibly a saw
  • Machines: percussion drill for stone, grinding machine
  • Materials: Frame dowels, mounting wedges and blocks, screws, sealing strips, expanding wood, mounting foam, silicone or acrylic, if necessary glaze / paint / paint / mortar

Install windows in 10 steps

  1. Hang the sashes to get to the frame.
  2. Remove the old window frame so that the opening to the outside is exposed. Only then can you install the complete new window.
  3. Remove old wall anchors and measure window reveal, lintel and parapet with the help of a ruler, protractor and spirit level. Between window and wall must be 1 – 2.5 cm space to foam the window later. At this point, you can also replace window sills and repair any damage incurred.
  4. Before you install the window, you should mount the window handle on the wing. Windows should be anchored at three points per meter, so the window will hold securely and will not tip.
  5. (optional) The installation of a sealing tape increases the energy efficiency of the window and prevents drafts. Sealing tapes for joints provide additional sealing between the window frame and the wall. Just attach them to the outside of the masonry.
  6. If you have followed all steps, you can now install the window. To do this, place blocks or mounting wedges around the opening to allow alignment of the frame.Additional blocks and wedges fix the frame to the window reveal, which you now have to align optimally. Otherwise, the window does not open properly, hangs or can not be installed.
  7. Hang the new casements. Tilt, open and test the functions of the window extensively before you install it completely and firmly.
  8. Screw the frame into the masonry with frame anchors and a special percussion drill for stone. The screws should be screwed at least three inches deep in the frame dowel and masonry to provide a minimum of stability. Before you finally install the window, you should then check all the functions again. Then you can insert expanding lumber and remove the assembly wedges and blocks from step 6. Before and after tightening the spirit level, check that the frame is really straight.
  9. After screwing in, you can install the window by foaming it with mounting foam (PU foam), fitting in the new window sills and plastering the walls. From our own experience we can warmly recommend the mounting foam of the company SOUDAL . Now wait until the foam has hardened.
  10. Finally, the window must be sealed from the outside and the inside with silicone or acrylic joints. Both materials are durable and insensitive. Here you will find instructions for clean joints .


In order to install windows, more planning work than actual installation steps are necessary. Once you have decided on the right window frame, determined the fittings, handles, stop and opening type, determined the right size and have all the necessary tools, machines and materials at your fingertips, you are ready to go.

The most important work is and remains the preliminary work – if you select and measure correctly and regularly check for straightness with the spirit level, the installation of the windows is faster. If you then look for friends or acquaintances as helpers who install the window together with you, you will soon stand proudly in front of the self-installed windows and