New build property – insulation & heating advice

[wmsteele]

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.

 

[htgeng]

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.

Any advice greatly appreciated.

Sounds bad. If new, then it should come under very stringent building regulations for energy efficiency.

Go to the building control office and request to see the plans for the house. That should show you how much insulation and what grade was used. You might be able to speak to the building inspector who signed off the job.

 

[JohnD]

I'm just an ignorant housholder but here's my two penn'orth.

you say "the top floor being double height with a sloping roof"

that's always going to be a prob. I used to live in a thing like an Oast house with an attractive exposed roof and a gallery half way up. All the hot air rises and the gallery would be boiling with the main hall rather cool. Very likely your roof has been properly insulated, but it won't hurt to check. Any draughts will allow cold air into the house to replace the hot that rises.

The walls, I expect will have insulation in the cavity, so you'd have to drill a deep hole to find it. Are the walls about 13" thick? As you're three-storey (like me) the inner leaf may not be of lightweight foamed blocks, as it has to support quite a tall heavy wall.

It's not usual to insulate intermediate floors as any heat passing from a downstairs room will just help heat the upper one.

Air passing from the garage into the house is relevant, because the garage is presumably cold. The main door is probably draughty. With luck the garage ceiling/floor above will have insulation in it (mine has). Look for gaps around the ceiling, especially around pipes, light fittings and ducts. I use expanding foam but it can be a messy nuisance when you first try.

Last thing - if you assume a typical room needs 3kw of heat, and a big room twice that, is your boiler big enough? (yes, i know this is not a scientific calculation). Have you got thermostatic valves so that you are not heaing unoccupied rooms?

 

[wmsteele]

Thanks for the feedback.

As far as I can tell the plasterboard walls are 12mm thick, after this it's a void (empty space). This is the same for both internal and external walls, difference being that you eventually hit brick on the external walls after the void. Concerned that I haven as yet found any evidence of insulation.

The garage needs further investigation. Will get the step ladders out tonight and give the ceiling a good look over. Hopefully it will have been insulated, as I assume it should have been. Still doesn't explain why fumes are getting into the bedroom above so quickly maybe it is a lack of insulation? Aren't garages ceilings supposed to be double lined with fire proof material anyway?

Main door to the house isn't that bad, as far as drafts are concerned. Traditional wooden type, not the best but not the worst.

Having a look at the original plans sounds like a good idea. At least I would then know what should have been done. Still not sure who to turn to for some professional advice. Ideally I would like someone to have a look at the house specifically looking at its adherence to building regulations regarding heating / insulation. Anyone have any ideas on who to contact?????

 

[slippyr4]

Setting the thermostat at a fairly reasonable 20c results in the boiler operating constantly, never reaching the 20c setting

Does the house actually get warm enough? or is it always cold? it's not that clear from your post.

It's entirely possible, and probably more likely, that your heating controls are wired up wrong and the boiler is ticking along when it doesn't need to.

As far as I can tell the plasterboard walls are 12mm thick, after this it's a void (empty space). This is the same for both internal and external walls, difference being that you eventually hit brick on the external walls after the void. Concerned that I haven as yet found any evidence of insulation.

Sounds like your external walls are dot-n-dabbed plasterboard. Behind that void should be brick or thermalite, then a cavity (which should be insulated) and then the outer skin of brick. How thick are the external walls overall? (tip: look at the sides of the window recesses).

Last thing - if you assume a typical room needs 3kw of heat, and a big room twice that, is your boiler big enough? (yes, i know this is not a scientific calculation). Have you got thermostatic valves so that you are not heaing unoccupied rooms?

I'd halve those estimates - the biggest room in my uninsulated 1930's semi needs 2.4 KW. Most small-to-medium houses get 12KW ish boilers, which has to go round all the rooms...