Two cold rooms in renovated house

Hi folks,

Gutted and renovated a 1960s house. House is cosy except for our downstairs bathroom and entrance hall which are both cold.

As I said, rest of the house retains heat really well as it's well insulated but once the heat is off, the downstairs WC and hall get cold quite quickly. All the other rooms have no such issues including a large open plan area.

Both rooms are north facing but living room and play room also with northerly aspect are fine.

Both rooms are under a porch and I think the pitched roof may be the source of the heat loss.

Builder says he will look into it and has promised to make good if it's something that should have been prevented from his end.

Anyone have any ideas what might be causing the issue?

Thanks in advance.

mickdw

Would need to see the layout really but it may well be something to do with roof you mention.

mickdw

mickdw wrote: »

Would need to see the layout really but it may well be something to do with roof you mention.

Hall and wc just to the right of the main door as you look at it:

mickdw

If your house has a cavity wall with partial fill Insulation, it's most likely that wind is blowing around in the free part of the cavity outside the Insulation and making it's way into ceiling of porch and into that hall and wc.

mickdw

mickdw wrote: »

If your house has a cavity wall with partial fill Insulation, it's most likely that wind is blowing around in the free part of the cavity outside the Insulation and making it's way into ceiling of porch and into that hall and wc.

Thanks for reply.

Original house had cavity wall with pumped bead insulation but the pre-purchase survey noted that the original porch was cavity block that had not been pumped.

We insulated the whole house internally during build.

To support what you say, issue is worse when the wind is blowing.

mickdw

Do you mean the porch is a double wall with unpumped cavity or built of cavity blocks (hollow blocks)
Also just looking a the bit of the house next door in the photo - did you build on top of a previous shed on the right side?

MicktheMan

OP, have your builder test for air tightness.

mickdw

mickdw wrote: »

Do you mean the porch is a double wall with unpumped cavity or built of cavity blocks (hollow blocks)
Also just looking a the bit of the house next door in the photo - did you build on top of a previous shed on the right side?

As per survey: "The external walls consist of 300mm masonry cavity wall construction.
The cavities have been pumped with bead insulation as evident by the core marks on the
external walls.
Note the side flat roof structure walls are cavity block and do not contain pumped cavities."

Front was originally a flat roof over the porch. Does that answer your question?

Demolished an existing garage, piled new foundation and built a two storey extension on right side.

mickdw

If main walls are all pumped and the porch is pumped, it can really only be an issue with the external soffit over the front door and the airtightness and Insulation within the porch roof.

mickdw

mickdw wrote: »

If main walls are all pumped and the porch is pumped, it can really only be an issue with the external soffit over the front door and the airtightness and Insulation within the porch roof.

Thanks a lot for input. That's my suspicion too.