Thermal Performance
High Levels of insulation - U values.

The table below illustrates the typical u values that are required to achieve the u values required to meet the u value required for a passive house.


Typical wall sections

Typical U values to meet building regulations are as follows
Walls - 0.22 w/m2k
Floor - 0.18
Roof - 0.15
Windows - 1.6

Typical values for a passive house are as follows
Walls - 0.14 w/m2k
Pitched roof - 0.10
Flat roof - 0.10
windows  - 0.9
roof lights - o.58 w/m2k
External doors - 0.9

How to achieve these U values - Typical Build up 

Wall Build-Up

1- Timber cladding 

2 - 38mm service void 

3 - Wood fibre insulation solid board. typically 100mm

4 - timber frame filled with flexible wood fibre insulation . typically 245mm

5 - 9mm OSB timber sheeting 

6 - Airtightness membrane

7 - 50mm ventilation gap

8 - plasterboard ( taped or skimmed)

Pitched roof construction

1 - roof finish , slates / tiles / metal 

2- 50mm ventilation gap

3- Wood fibre insulation solid board. typically 100mm

4 -  flexible wood fibre insulation . typically 300mm

5 - 9mm OSB timber sheeting 

6 - Airtightness membrane

7 - 50mm ventilation gap and plasterboard finish 

Flat Roof Construction

1 - green roof (optional )

2-  single ply flat roof waterproofing 

3 - 18mm wbp plywood

4 - ventilation . 100mm

5 - breather membrane

6 - wood fibre insulation solid board . typically 120mm thick 

7 - wood fibre insulation flexible - typically 220mm thick

8 - Airtightness membrane

9 - 38mm service void

                                                                   10 - plasterboard finish 

Windows and Doors

All glazing must be triple glazed. We work with a number of different manufacturers all offering exceptional quality products. 

Passive house standards 
Passivhause standards require a figure equivalent to less than <0.6 air changes /hr @n50.  

How to achieve an excellent air tight building

Airtightness is achieved by installing an airtightness membrane wrapped inside of your home onto the timber frame of the building and behind the plasterboard.  This membrane ( intello shown in the attached photos ) is taped to the walls and ceiling and around each penetration. Careful attention must be paid to ensue that all the tapes are correctly installed. Challenging areas are corners, penetrations and windows and doors. 
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