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Oak Frame Newbuild, Devon

A 190m2 newbuild house has just been completed by Oakwrights in green oak frame for clients in Devon. The project has aimed for high levels of energy efficiency and has been designed using PHPP (Passivhaus Planning Package).

21° designed, supplied and commissioned the MVHR system for the project as well as supplying ULTRA triple glazed timber windows and doors. 21°'s consultancy service provided PHPP modelling for the house to optimise its energy performance.


The barn-style project has achieved the top rating in SAP and got an airtightness value of just less than 1 ach/ hour. The project was designed using PHPP and a few design elements such as rooflights and form factor meant that the project did not manage to achieve the full Passivhaus standard.


Triple glazed timber windows & doors

21°s ULTRA range of triple glazed timber windows and doors was chosen for the project, including inward opening windows, single doors boarded with grooves and outward opening double doors. All the doors and windows were finished in paint finish colour RAL 7010.

We chose the ULTRA range because it offered the U values and thermal efficiency that we needed on the project. The ULTRA windows and doors look very nice and people comment on how smart they look.


MVHR heat recovery ventilation

A PAUL Novus 300 MVHR system with rigid steel ducting was designed, supplied and commissioned for the project.

We don’t notice the MVHR system – it is just ticking away on its own. We barely touch it and hardly ever need to use the ‘Boost’ button. The MVHR maintains a healthy level of humidity (40-50%) within the house so we have not had any condensation even in the coldest weather, and have the added bonus that laundry dries very quickly.



21°s consultancy service modelled the project using PHPP (Passivhaus Planning Package) which helped the decision-making stage of the project and resulted in a number of key layout and detailing changes early on in the project.

Project details



Case study


Life changing homes