Heating an empty building

[MarkC]

Hi everyone,

I co-own a small single story thatched cottage in Essex (2 up 2 down). It is very old but well maintained and mostly sound. It is a holiday cottage and usually unoccupied. For at least the last 50 years it has benefited(?) from background heating over the winter months from 2 storage heaters. This was an easy decision when electricity was cheap. The thinking was that by putting heat into the property when unoccupied it would in some way safeguard the physical structure of the building, by warding off damp or by some other effect. I would like to re-assess this plan and work out whether there would be any detrimental effect to the building by leaving it unheated over winter whilst unoccupied.

Can anyone advise? I wonder whether by changing the habit of a lifetime I may end up with a precious place falling into disrepair.

Thanks

Mark

 

[CliffordPope]

My first thought is that ventilation might be better than heat. Presumably with permanent background heating you've not been giving it too much ventilation, because obviously that would lose the heat?

 

[Cubist]

Hi Mark,

To my mind the key consideration is the nature of the internal water supply. Assuming the cottage is broadly weather-tight then the most significant risk is that of water distribution pipes repeatedly freezing and thawing. This can lead to the development of minor leaks at the junctions of pipe fittings, pin-hole leaks and even catastrophic failures of a pipe or a storage tank. Whether you heat the house or not you should, if it is to be left empty for long periods, shut down the external water supply and, if you intend to not heat the place, drain down 'all' the internal water distribution systems including the hot water cylinder and cold water storage tanks.

The last thing you will want to find after leaving the place for a few months is that the place is being continually flooded. Not least because of the bill if your water is provided by a utility company. The damage to the house both immediate and long term could be horrendous.

Cheers,
Steve

 

[Gothichome]

I may not be the best person to answer this never having to deal with a thatch cottage but I would be inclined to leave the heat on. If nothing else the heat will stabilize the humidity level of the building, once the inside gets cold and the dampness sets in it will take a lot of time to drive the dampness out, repeat cycles of damp, freeze and warming can play havoc over the long term. Just my thoughts.
Ron

 

[worms]

Regardless of what might work best for the fabric of the property, it is quite likely that your insurance company will have its own views on this. I've seen one insurance company insist on a minimum of 10C and another that stipulated that the temperature in the property wasn't to fall below 16C. :shock:

 

[CliffordPope]

I'm assuming that the heat was not exactly "on" but set at a very low level in an attempt to keep the damp out?

I don't think that would keep a level humidity,it would rise and fall anyway with weather changes. It would simply cause the average temperature to be slightly higher, and warmer air would hold more moisture than colder. I've never noticed an old building with broken windows, doors left open, etc to be especially humid, simply freezing cold.
The only way to keep a building bone dry would be leave the heat on at a permanently high level .

I think structures survive pretty well just left in the open air, as long as rain is kept off. It's sealing off all the doors and windows and partly heating them (and living in them) that sets up the cycle of humidity changes that causes condensation.