The challenge - how can we transform a Victorian home in a conservation area into a comfortable and healthy low energy home that meets Passivhaus standards?
Install a whole house ventilation system
- Noisy extractor fans are not needed in the kitchen or bathrooms.
- No trickle vents are required in windows.
- Stale inside air is constantly replaced with filtered fresh air, with pollen and allergens removed.
- Healthy humidity levels are maintained, reducing dust mite levels.
Fact: U value measures the ability of a material to prevent heat loss – the lower the better! The walls will have a U value of no more than 0.1. Current building regulation requires only 0.25.
Recycle and use natural resources
A constant supply of hot water is produced by solar thermal panels on the roof and by capturing heat from waste water and stale air via the MVHR.
- Hot water is generated during daylight hours and stored for use throughout the day.
- Bricks and timbers from the original building are reused where possible.
- Air will be passed through the underground heat exchanger to use the constant natural temperature of the ground (13 degrees) to pre-heat or pre-cool (depending on the season) the air before it enters the house.
Fact: The hot water produced by the solar thermal panels is stored in two hot water cylinders to provide enough hot water for at least two days for a family of four. This is to make sure hot water is available even if sunshine is limited.
Stop heat from escaping
The external walls are entirely lined (on the inside) with thick, high performance insulation and an air-tight layer. This ‘internal blanket’ ensures that no heat can escape the house, which minimises the need for heating, even in winter.
- Custom made triple glazed windows and doors continue the airtight layer and meet strict conservation area requirements.
- Thermal bridging is minimised preventing heat from escaping where the insulating layer is interrupted e.g where the basement or floors meet the wall.
Fact: The only thermal bridging in the home on the external walls is the carbon ties which have very low heat transfer properties.
Maximise space and comfort for tenants
- Removal of the chimney breast compensates for any space lost through installing insulation.
- A+ rated appliances and low energy lighting will be supplied.
- Refurbishment of the previously unusable basement creates an extra bedroom and bathroom.
Fact: The design of the insulating layers means that tenants can still hang pictures using shorter nails – this is traditionally not possible in a Passivhaus due to its airtight nature.