Opening Watti Energy Windows

Depending on the selected glazing Lammin Watti Energy Windows can be executed in many different energy classes. A++, A+ A or B. Watti Energy Windows are suitable for new building and renovation.

Watti Energy Window is ideal for your home and year-round-heated cottage

The Lammin Watti windows are designed keep the generated heat inside the house. That’s why Watti is a good window choice for home and leisure homes which are used all year. Watti windows are commonly used in renovation projects and in new building. The exterior structures are of aluminium-clad wood. The aluminium cladding makes the window maintenance-free and highly weather-resistant.

Quadruple-glazed Watti window retains heat effectively

The price of energy rises year by year, and the environmental impacts of home heating are becoming an issue for more and more people. A quadruple-glazed Watti window is a good choice when it comes to saving on heating costs. It's also a good alternative from the home value viewpoint - in the future, energy efficiency is likely to be increasingly more weighted for the resale value of the house.

We deliver Watti Energy Windows with the accessories you wish for example, with blinds. Read more about window accessories!

Technical information


0.70 – 0.76 W/m2K, depending on glazing.

Sound reduction index (Rw):

43-47 dB, depending on frame depth and glazing.

Aircraft noise insulation (Rw+C):

41-46 dB, depending on frame depth and glazing.

Road traffic noise insulation (Rw+Ctr):

38-43 dB, depending on frame depth and glazing.

Air tightness:

In compliance with standard EN 12207, classification 4.

Rain tightness:

In compliance with standard EN 12208, classification E 1050.

Resistance to wind load:

In compliance with standard EN 12210, classification C3.

Inner sash glazing:

Double selective insulation glass with Argon gas.

Outer sash glazing:

Double selective insulation glass with Argon gas.

Inner sash material:

Knot-free finger-jointed pine.

Frame material:

Two sides of knot-free finger-jointed pine.

Outer sash and exterior cladding:



Threefold seal.


Financing service

If you need funding for your window and/or door purchase, it is easy to apply. Complete the application on our website, and you will get the credit decision immediately.


If necessary, we will come and measure the window and door frames on the spot. This is to ensure that the new windows and doors will fit your home perfectly.

Home delivery

We deliver the windows and doors securely directly to your site within the agreed schedule. We can also help you when you need windows and doors to your site at short notice: you will get stock products from us even in 1-2 days delivery time. 

Order just the kind of window you need

We design and manufacture the right windows just for your home. This means a tailor-made look, excellent weather resistance and the best guarantees in the industry.