Buy and install plastic windows - what do you have to pay attention to?

For the plastic window purchase, there are numerous, often well-known tips. Often, however, is not thought of the installation. The window installation causes costs and effort, and must be considered when buying a window in any case.

Calculate installation costs

The first, fundamental question when buying a window is: who builds the window after? Many window manufacturers also offer their own installation service - either directly themselves or through partner companies.

Conversely, many specialist companies also sell windows. In both cases you get both services practically from one source. This almost always means a cost advantage, considering the total cost.


Of course, it is optimal if the windows are installed by the same company where they are used. This avoids a back-and-forth blame for subsequent problems between window manufacturer and einbauendem operation.

If both are delivered from one source, it does not matter if there is a mounting error or the window was damaged. There is then a single contact person who is in any case obliged to provide a functioning and tight window, no matter what the error was in the end.

Costs with separate window cover and installation

Many companies charge surcharges when they need to install windows that are not from standard partners. Most of the time is also a bit higher when it comes to windows with which the installation team is unfamiliar.

In any case, one should obtain offers, and compare both price variants before a window exchange.

Deductibility of installation costs

In the case of energy renovation or modernization of the living space, the tax office allows the deduction of the craftsman's costs from the income tax. However, this is only possible if - even if the fixed price has been agreed - the assembly costs and the material costs are strictly separated from each other on the invoice.

Deposable are then:

  • the labor costs for the craftsmen
  • the journey costs are shown on the invoice
  • these costs but only up to the maximum design limit currently 6,000 EUR) per year

The tax office then reimburses 20% of the craftsman's costs. Another requirement is that the bill is not paid in cash, but the invoice amount was transferred to the account of a specialist firm, and you prove the corresponding tax office.

Tips & Tricks

If you buy windows from Poland, be sure to ask several craft shops, what cost they will incur for installation, and whether to install Polish windows at all. Make sure you compare the individual offers for installation.

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