Why is this room so cold?

[MisterBoy]

Our main sitting room is unfortunately the coldest room in our house and I'm wondering what would make the most difference.

It's a downstairs room 5x5m in an old, solid brick 1860s property. It's on the north side of the house but only has one exterior wall (most of ours have 2) most of which is taken up with a huge chimney breast (the chimney is sealed so no draughts).
And the rest is 90% windows, one is double glazed the other an old single glazed sash.

It is the only room in the house with a solid (concrete) floor, the others all have suspended wooden floors and I'm wondering if this could be a factor? Obviously the old window isn't great but is one window realistically going to make a big difference? There's very little wall to insulate.

 

[Scarlet Pimpernel]

I think you already know the answers.
Your floor is uninsulated, your walls are uninsulated, your windows are suspect, your room is on the north and receives little solar gain but the worst of the wind, what about the ceiling? If the rest of your house is not insulated there's a real chance that your ceiling is also not insulated.

 

[freddiemercurystwin]

Perhaps that room is haunted?

 

[MisterBoy]

I think you already know the answers.
Your floor is uninsulated, your walls are uninsulated, your windows are suspect, your room is on the north and receives little solar gain but the worst of the wind, what about the ceiling? If the rest of your house is not insulated there's a real chance that your ceiling is also not insulated.

Why would you insulate the ceiling anymore than you would an internal wall?

As you say I know all the reasons it's cold, but not why it's colder than other rooms. Even the other room on the north... Which is a corner so has 2 external walls and a huge single glazed bay window... Is less cold.

I'm asking which thing would make most improvement, or give most bang for buck. Is a concrete floor likely to make a big difference compared to an (uninsulated) suspended floor or is that a red herring?

 

[MisterBoy]

Perhaps that room is haunted?

Since that's not a thing, I doubt it

 

[freddiemercurystwin]

Perhaps your house was built on an old Indian Burial Ground?

 

[JohnD]

is the concrete floor original? Or was it tipped in to hide a leak after a wooden floor rotted?

You could check the temperatures of the walls and chimneybreasts, in case you spot the cold one (e.g. if the chimney is damp, and airflow is evaporating off the water, it will be cold)

Are you sure it's not just heat loss from the large window? And, facing north, there will be no solar gain?

Carry a smoking joss-stick around the room looking for draughts. Old sash windows can be very draughty but that plastic film is effective.

 

[MisterBoy]

How would I tell if it's original or back filled @JohnD? I've wondered myself, I'm not sure if concrete floors were used 150 years ago but we think this might have originally been the kitchen so possibly flagged?

I like the idea of trying to measure. Regarding windows, it doesn't seem to make a huge difference even closing some write thick curtains we added. Less draughty but not much warmer.

 

[JohnD]

have a look at the threshold, skirting and architrave. Does it match the other rooms, and does it seem original? If it used to be suspended timber, there would have been airbricks to ventilate the void.

I had an old house where some of the floors were terrazzo on concrete, and another quarry-tiled. In the kitchens there were definite dips in the traffic paths and in front of the sink and cooker, I think from wear.

if you put a piece of clear plastic on the floor, taped down at the edges, you will see if the floor is damp, because condensation will collect under the plastic. (you can do it on walls, too).

 

[Scarlet Pimpernel]

Why would you insulate the ceiling anymore than you would an internal wall?

Sorry, I missed the "downstairs room" bit that you mentioned. It's obviously a two storey house. I somehow imagined it as a bungalow.
But I agree with John, check for draughts first. Then check the efficacy of your windows and double glazing, and as John said, check for damp.

 

[MisterBoy]

We definitely have some damp coming up... We had a box in the corner and when we moved it there was a mouldy wet patch underneath from condensation.