Passivhaus standard windows and doors

To complement the air-tight, well insulated structure of your home it is vital that windows and doors are manufactured and installed to a similar high specification. These must be super-insulated, draught proof products and they need to be fitted in such a way that no air escapes around the edges of the frame, which is a common problem when windows are poorly installed.

Typically, these windows are clad in aluminium to the external face to minimise the need for maintenance, triple glazed and draught free, with special attention paid to minimalise and eliminate thermal bridging through the frames.

We are currently recommending Internorm/Ecohaus and Green Building Store triple glazed windows for the majority of our current projects.

The window market is very competitive, but  these companies stand out in that they have their own dedicated install teams.

Because the installation process is as important as the quality of the product itself when it comes to efficiency, we strongly recommend that you ensure your supplier will both supply and fit your windows and doors to passivhaus standard, rather than simply supplying the product for you to oversee the installation of yourself.

ecoHaus Internorm

Ecohaus Internorm have supplied and fitted the windows on a number of our projects, including Weymouth Passivhaus and Brindleshaw barn. Our clients have told us how impressed they were by the professional manner in which Ecohaus handled their commission. EcoHaus arranged to be on-site to take delivery of the products, and then set about the installation process without fuss, with no expectations from the clients to be involved or give directions to the installation team.

EccoHaus triple glaze window

Outward casement

  • Inward opening
  • Triple glazed
  • Aluminium clad exterior to RAL colour
  • U values to 0.6 / 0.69


Green Building Store windows

We have used Green Building Store windows on some of our projects. These come in two main options: the PERFORMANCE with u-values to 0.85; and the higher performance Passivhaus certified ULTRA which offers u-values to 0.68.


These are ideal for both traditional and contemporary build projects. The tilt & turn style offers a "European" appearance and can be used interchangeably with the casement option for design versatility.


Outward casement

  • Inward tilt & turn
  • Triple glazed (with double glazing option)
  • Whole window U value: 0.81 W/m2K
  • Mock sliding sash option
  • FSC 100% certified laminated redwood (or oak)


High performance, cost-effective timber window range developed for Passivhaus and low energy projects. Up until now it has been hard to source outward opening casement windows for Passivhaus & low energy projects. The ULTRA outward opening range has been developed to help fill this gap.


Outward casement

  • Triple glazed
  • Passivhaus-certified insulated frame option
  • Whole window U value: 0.75 W/m2K (solid frame option)
  • Whole window U value: 0.68 W/m2K (Passivhaus certified, insulated frame option)
  • FSC 100% certified laminated redwood

Green Building Store: Progression

The PROGRESSION window creates an appearance with minimal frame visible from outside - the rain screen covers most of the window frame so creates a minimalist modern look. U values are 0.68 so are suitable for passivhaus projects where inward opening windows are acceptable to the client.


Green Building Store: Rationel

Fox Barn (as seen in our gallery) is one of many of our projects in which Rationel windows have been installed, and has been featured in their series of case study brochures. The Rationel range tend to be slightly cheaper than the competition with a minor reduction in insulation and quality. At the time of writing, Rationel do not have their own dedicated install teams, and instead rely on a network of independent fitters, which has led to some quality issues on past projects, with different teams having different abilities.