Weavers Cottage update!

We're very behind with blog posts. The Weavers Cottage deep retrofit is now finished and has been lived in for over a year! The owners are reporting great comfort and low energy bills as expected from the PHPP modelling, and commented "It feels like being hugged by the house. The indoor air quality is brilliant too -and no mould or condensation!"

The owners are currently considering whether to undertake AECB Retrofit or EnerPHIt (component method) certification for the project as the airtightness test came in a 1.1 ach @ 50Pa, which is very close to the EnerPHit requirements. We'll share any updates on that when we know more.

A summary of the insulation and airtightness measures at the project is below:

• Upstairs on original stone walls:  25mm mm of Diathonite Thermoactive flattening, 60mm of wood fibre and 10mm of Lime Green Solo.  U-value 0.365 W/m2K

• Downstairs on original stone walls:  25mm of Diathonite Thermoactive flattening, 80mm of wood fibre and 10mm of Lime Green Solo.   U-Value  0.336 W/m2K

• Stone partition walls:  approximately 25mm of Diathonite Thermoactive

• Cold roof space:  400mm mineral wool.  U-Value 0.128 W/m2K

• Kitchen extension cavity wall:  Wall tightened up internally, 95mm Earthwool batts 95mm and EPS 80mm/ OSB 15mm vertical studs, covered by Intello Plus and carefully taped and finished with plasterboard.  U-Value 0.287 W/m2K

• Kitchen floor:  PIR 100mm with chipboard.  U-Value 0.205 W/m2K

• Kitchen flat roof:  240mm Rockwood Hardrock Multi Fix dd (4 x 60mm) 240mm, as part of a flat roof system; Intello Plus, rafters with services running through, OSB or plywood, Calculated U-Value 0.151 W/m2K

The services strategy included an ASHP for heating and hot water and a PAUL Focus MVHR (mechanical ventilation with heat recovery) system, both from 21 Degrees.