edwardian house early 1900s - type of walls?

[Coco9]

apparently it's easier and cheaper to insulate the walls if they are cavity walls as opposed to straight walls - does anyone have any idea what they are likely to be in a house built in 1904? A full survey would probably tell but not at that stage yet.

Unlikely to be cavity walls, I think.

My last house was built around that time (1906) and did have cavity walls. It was one of those typical of the period with bay windows at the front.

At that age it is extremely unlikely to be cavity walls. It might have an unusual kind of brickwork called rat-trap bond, which has gaps but is not a true cavity wall, especially if it is quite a large house. I don't think the approval for CWI would permit it to be installed.

In some cases there will be lath-and-plaster attached to studwork fixed to the inner surface of the walls, where there will be a gap between the plaster skin and the brick or stonework. Again this is not a true cavity wall and you couldn't blow in CWI, though you could strip it off and replace with insulated drywall.

1905 and cavity here (insulated)

1911 here, cavity walls but unsuitable for CWI as we are near the sea and get driving rain, sand, etc so apparently it predisposes the house to damp. Make sure you check it out carefully OP. We have had several companies try to sell it to us but surveyors and reputable companies all say no.

Is the brickwork visible? Cavity walls are normally stretcher bond, all long bricks, solid nine inch walls have "headers" visible i.e. the ends of the bricks.

1925 here and no cavity walls, just single skin brick. (which led to it needing to be insulated with polystyrene stuff round the outside then rendered to stop it being horrendously damp)

thanks this is helpful though would need to go ahead with the survey to find out for sure

What fossil said - look here

you can actually tell by measuring the thickness of the walls. Do it at a doorway or window where you can touch both the inner and outer surfaces.

An English brick is nine inches long and four inches wide (ish). If the wall is about ten inches thick, it will be a single brick plus the depth of the plaster

If it is thirteen or fourteen inches thick, it will be two separate leaves, plus the cavity, plus the plaster.

Yes, you can also tell at a glance by looking for the presence or absence ot Headers (brick ends) in the wall, provided it is not rendered or painted.

Sometimes window bays and porches are built differently to the main house wall, and may be only half a brick thick.