Need some advice on a new property that I moved into this summer. With winter now setting in and temperatures falling I have become increasingly concerned with the buildings insulation / heating.

A fairly powerful 35kw combi has been installed. Radiators all perform as expected with no cold spots on any of the panels. Thermostat controls are in the main hall on the ground floor. Setting the thermostat at a fairly reasonable 20c results in the boiler operating constantly, never reaching the 20c setting.

Its been really cold for a few nights now and I am getting really concerned about this. As far as I can tell the combi is working correctly. Its the ability to retain heat within the house that appears to be the problem.

How can you tell if your house has been insulated properly??

Don't say have a look in the loft, lol, I don't have one! The house is split over three floors, the top floor being double height with a sloping roof. I know that the cavity between floors (2nd/1st & 1st/ground) is not filled. The ground floor is concrete, again no insulation, with the floor boards fitted to wooden batons.

Is it possible that the floor cavity's should be insulated?

The internal and external walls show no signs of being insulated. Since moving in I have fitted my fair share of shelves, curtain rods, blinds. Not once have I drilled and found any evidence of insulation within the walls. Not being in any way clued up about building regulations I am not sure if this is normal.

How can I tell if the house is properly insulated? Is it possible to get it inspected in some way??

Another issue that cropped up this morning was caused by the car being garaged last night for the first time (saves me from scraping!) Started the car up this morning in the garage but needed no move some boxes that had fallen over during the night before driving out. We are talking about 10 minutes max with the garage door fully opened, within this time the bedroom above, where my wife was still in bed, was filling with exhaust fumes. Garage doors aren't exactly air tight and as it isn't heated it would explain the ice box conditions in the master bedroom.

The big question is who do I turn to? I want to get a professional advice before contacting the builder / NHBC. Just not sure who I should be contacting.

Any advice greatly appreciated.