Most of our granite homes were built when energy was cheap and coal was in plentiful supply.
Granite homes were designed to be "water-vapour-open" meaning that sources of internal moisture (from cooking and bathing) and sources of external moisture (from wind driven rain and ground moisture) were allowed to permeate through the fabric of the house and any accumulation of moisture was avoided by high levels of ventilation throughout the home.
The high levels of ventilation mean energy losses in granite homes are very high (frequently more than 300kWh/m²yr), but care must be taken when making these buildings air-tight for fear of allowing moisture in the fabric to accumulate.
Old buildings must be allowed to "breath".
Best Practice Approach
Walls
Typically external walls have no insulation between the stone wall and the plaster linings. Walls can be insulated externally or internally, but obviously there are constraints.
It's really important that wall insulation is designed and installed by professionals who understand the local situation.
Read our Granite Wall page for more information
Roofs
Roofs are complicated because most of them have dormer windows installed.
The best way to insulate the roof is between the rafters, with appropriate insulation. This can be done from the inside or the outside, depending on your budget and how much disruption you're willing to accept
The best time to do this is when the roof needs repair.
The pattern book offers different solutions to achieving this.
Floors
The majority of granite dwellings have suspended timber floors with a void underneath. If this void is deep enough for access then this can be once of the most cost effective insulation measures.
If the void is too shallow then insulation can be installed above the flooring, and there are advantages to this approach as well.
The pattern book offers multiple solutions to this problem depending on the specific situation
Tricky areas
Bay Windows
Although a beautifully detailed feature of many granite homes, the way in which they penetrate the walls of the home mean they are usually hard to insulate well and cause a lot of thermal bridges.
Stripping the timber panelling can allow for
Period Features
One of the many attractions of living in a period property is the ornate details, skirtings and cornice work that adorn them.
Naturally if we are to add insulation to
Entrance Porches
While many appreciate the convenience that an entrance porch brings, their thermal efficiency is often falsely praised.
When designing an energy efficient building one must be clear about where the line of insulation and airtightness lies. In an entrance porch neither doors offer much thermal resistance although the outer door may have weather seals.
This Pattern Book will be available for distribution in the coming months. Please check back for updates or get in touch