Eco House: The Five Fundamental Principles Of Your Eco House
Airtightness
Ventilation
Insulation
Thermal Bridges
Windows and Doors
When building your new eco house, or retrofitting an existing house, airtightness is key.
Buildings are designed with a ventilation strategy
Ventilation systems such as MVHR holes in the building fabric such as trickle vents.
Aside from designed ventilation, there will also be undesirable ventilation.
This unwanted ventilation, is a lack of airtightness that was either not designed when the building was new, or a hole created at a later date.
Undesirable ventilation fixes will reduce heating bills, reduce drafts &reduce mould risk.
A better bank balance, more comfortable house and better indoor air quality are all reasons to get this right.
The Airtightness golden rule is for it to be continuous
Eco House Airtightness
Ventilation For Your Eco House
All buildings require ventilation of the indoor air and also of parts of the fabric.
We ventilate indoor air for 2 main reasons.
To dilute indoor air pollutants
To remove water vapour that can be a source of damp and mould
There are three main methods of ventilation:
Natural ventilation
Mechanical ventilation
Purge ventilation
We must ensure that our ventilation strategy is both quiet and energy efficient.
Taking all this into account, The design of a ventilation strategy is important.
New build houses may be easier to specify, and retrofits slightly harder as the original building will have been changed to include undesirable ventilation
Good airtightness and well designed mechanical ventilation will produce the best indoor air quality results.
Insulating buildings can help in two ways.
It can keep heat in when the outside temperatures are cooler
It can help keep heat out when outside temperatures are higher.
As with airtightness, insulation should be continuous, any gaps will be the path of least resistance for the heat to escape through.
Floor insulation should meet wall insulation, that should meet roof insulation.
Insulation strategies may be inside a cavity, external or internal.
The design of an insulation strategy becomes more critical when insulating from the inside as moisture problems can be caused causing the potential failure of building fabric components.
Insulation
Thermal bridges
Often overlooked by general builders are thermal bridges.
A thermal bridge is a piece of building fabric that has limited or zero insulation and provides a path of conductive heat transfer from inside to outside.
The consequence of these heat paths is that heat can easily escape or enter the building.
Thermal bridges are often repetitive in a building, so if one exists it is likely that there are more.
When there are multiple thermal bridges the consequences can become significant.
Potential thermal bridges can be calculated to prove that they have been suitably mitigated.
The supply of windows and doors is an industry of its own within construction.
Having to perform so many purposes they are complex components in a building.
They must keep the wind & rain out, whilst letting the sunlight in.
They don’t want to let to much sunlight in as this may add to summer overheating risk.
Whilst letting light in they shouldn’t let too much heat out.
All this and they often have to move to open whilst maintaining a suitable level of security.
They have three key components, the glass, the frames and the detail of how they connect to the building.
Once installed, windows and doors need to be airtight, provide ventilation, be insulated, and be thermal bridge free.
Eco House Windows and Doors
Creating Your Eco House
These 5 fundamental principles of your eco house are complex and designed with building physics.
To ensure you achieve the best value for your investment it is important that these principles of construction are designed and verified by experts.
We can help you find the right designers and contractors. If you are looking for eco builders in West Sussex Ecohaus can help.