Installing new window frame with insulation glass HR++ was a best job. At the front of our house we had already installed double glazing. The back was a bit more difficult because the window frames were hoisted over a high hedge with an aerial platform.

Why plastic window frames?
We didn't choose plastic window frames. We opted for wooden frames. We find that more lively. The maintenance is a bit more intensive, but we are willing to do it. Sanding and painting the window frames every five years.

The frames with the windows in them were installed by a construction company. The frames on the second floor were already primed. We painted those ourselves.
We finished the window frames on the first floor with oil.

Why a sliding door?
We didn't choose a sliding door. We use the garden a lot and the door opens and closes constantly. The dog often goes out into the garden and we often sit by or in the pool. We can just open the garden door, but we can also turn it into two sliding doors.

Lower energy bills?
We noticed it pretty quickly. The house is now well insulated. New window frames and double glazing is an investment, but our gas bill is already down. Better for the environment and for ourselves of course :-)