ok, so what is passivhaus ?


the passivhaus standard, first established by building physicists in germany some 25 years ago, has been rigorously tested + refined since then


adopted internationally by forward-looking designers and clients, it is now being used for a wide range of buildings - from houses to schools + from new-build to refurbishment.


in the UK, it is still in an earlier phase of adoption - although thousands of passivhaus projects exist

some simple aspects of the low energy  / passivhaus approach are illustrated here:

and living proof below that PH does not equal soul-less... 

a norfolk social housing PH scheme by parsons whitley >>>

the essentials...


of the standard are derived from scientific research to find a building-fabric based approach achieving exceptional warmth and comfort 


derives both from super-insulation of all external elements

 - walls, roofs, floors, windows + doors  +  minimising cold-bridges

 - and high levels of airtightness to enable controlled  ventilation


is achieved by both warmth, the lacks of drafts  through excellent airtightness, and comfort ventilation  - whole-house mechanical ventilation with heat recovery [mvhr]

open source

most uk passivhaus designers are working in an open source way, sharing their rapid learning on this pioneering UK approach

the details...

for the technically minded, the  following standards are a guide to passivhaus design, although every scheme is modelled in great detail

cosy - very low ‘U’ values:  ± 0.1 w/m2k

comfortable + draft-free - 0.6 ac/h air-tightness needs to be achieved not only in theory [hard] but also in practice [much harder]


in addition, the standard rigorously designs away cold-bridges - the little ways that heat escapes through the structure 

the whole design is achieved using specialised software - the PassivHaus Planning Package [PHPP

but equally important is the quality on site - needing special attention to details such as airtightness membranes

enerPHit barn conversion, crickhowell | 2016


this project is complete, a converted grade II listed barn built over 200 years ago into a house suitable for the next 200 years, targeting the passivhaus enerPHit standard


located in the brecon beacons, the site offers an unusual combination of rural peace and village facilities - completed 2016