What can I do about cold areas in my home? (without causing problems)
Do you have an area of your home that is too cold to use as you would like? Often this can also be an area with condensation a mould growth, and so not a valuable part of your home.
As Architects who specialise in environmentally friendly warm comfortable homes, we often have clients come to us with cold, draughty unhealthy buildings and we do our best to change things round and make them warm, cosy, health spaces that can be used, without the owners resorting to salopettes and face masks.
Looking firstly at the building physics, heat wants to move towards cold areas so if its cold outside the heat will want to escape, heat is lost in a number of ways, and can be explained with our tea pots:
- Efficient shape – heat is lost through the outside surface, – the bigger the area the bigger the heat loss – so a round tea pot is more efficient than a square.
- No Draughts – leave the lid off your tea pot and the heat will quickly escape, this is one of the biggest areas of heat loss in a building. Have you noticed your house is coldest on a windy day rather than the coldest day outside?
- Cold bridges – Metal and other highly heat conductive materials can bypass any insulation and form a quick way for heat to escape. Such as a spoon in a cup of tea.
- Putting a tea cosy on your pot keeps it warm, so does adding insulation, but ensure there are no gaps.
However, be warned, you need to be very careful to avoid interstitial condensation – this is condensation within your structure. Basically, moisture in the air will condense and turn into water at about 12° C (depending on humidity, higher temp in bathroom) you do not want this happening in the middle of your wall particularly at wooden joists and framing that are at risk of rot. For this reason, you are limited to the amount of insulation you can add internally.
1, Add insulation externally if possible
2, Ensue a continuous air barrier on the inside of the insulation to stop moist air getting into the walls, and causing draughts.
3, Ensure the insulation is continuous and tight fitting, leave bigger gaps that can be filled easily rather than small ones that you only fill the front.
4, If adding insulation internally, return the insulation into the reveal onto the window frame otherwise the heat will bypass the insulation.
5, When upgrading windows go for triple glazing – the body can detect 4° C difference in air temperature and surface temperature, with good triple glazing the temperature difference is less than 4° even on the coldest days (freeing you to put your radiators elsewhere).
6, Consider using breathable natural materials that allow air and moisture to move in and out of the walls.
7, If you can reduce the area of heat loss by removing a recessed front door, or projecting window.
8, Keep any metal fixings through the insulation to a minimum.