Insulating our conservatory

[H F]

Our conservatory is freezing at this time of year. 
 

It has massive double glazed windows, two poorly executed roof windows and from a rough investigation, no insulation in the roof/ceiling. The roof window is not double glazed - just a thick pane. 

 

How can we better insulate this space? At the moment this room is freezing and we would like to get it a tad warmer as the cold can get into the main house via the two doors.

 

Please excuse the big box in the photo. Didn’t feel like lugging it around. 

[Gone West]

Do you need the roof windows? If they are poorly fitted single glazed and you have enough light without them then remove them and insulate the whole ceiling. Without knowing how the roof has been constructed it's a bit difficult to recommend the best way to insulate. Maybe use a small metal detector and magnets to find fixings in ceiling so you can find rafters and noggins then blow in beads?

[AliG]

I can't believe someone would build something like that without insulating the roof. It clearly would have failed building regs if that is the case.

 

Fixing the roof should be your first job before doing anything else.

 

If you want to keep the windows then you'll need to replace them with something with a much better U-Value or do away with them as suggested.

 

But most of the area is roof so really fixing that is the most important job. I think you may as well open it up and see what you are dealing with. You need to know how it is constructed to know the best way to insulate it.

 

Even with a better insulated roof if that is older poor U-value double glazing in the sides it is unlikely that it will be easy to heat in the winter, but it might stop you losing enormous amounts of heat.

 

I would also look at draught proofing the interior doors. We had a conservatory in our old house and while we were working on it a few years ago removed the internal doors. Our gas bill absolutely skyrocketed.

[Ed Davies]

Is that a conservatory from the planning/building regs point of view? I thought they needed more glass in the roof to count.

[Onoff]

Do you have any heating in there anyway?

[Ferdinand]

4 hours ago, AliG said:

I can't believe someone would build something like that without insulating the roof. It clearly would have failed building regs if that is the case.

 

If a conservatory is outside external quality doors and windows, I believe it does not need building regs:

 

Quote

Building regulations will generally apply if you want to build an extension to your home.

However, conservatories are normally exempt from building regulations when:

• They are built at ground level and are less than 30 square metres in floor area.
• The conservatory is separated from the house by external quality walls, doors or windows.
• There should be an independent heating system with separate temperature and on/off controls.
• Glazing and any fixed electrical installations comply with the applicable building regulations requirements (see below).

https://www.planningportal.co.uk/info/200130/common_projects/10/conservatories/3

 

That is what I did with one of mine which is really a sun lounge.

 

Reversing what I said on the other thread now that the whole roof is in question, I would consider replacing the roof with an insulated corrugated one. Mine is insulated with 100mm rockwool, which is not really that much (+ 75mm PIR underfloor and 50mm PIR in the dwarf walls). Not that well insulated by BH standards, but the tenant uses it as a lounge for 80-90% of the year.

 

My conservatory at home, which has a glass rood, has 100mm PIR everywhere where there is floor or wall, but is also divided off by UPVC 2G French Doors from any inside rooms.

 

Here you need to find out what insulation you have - are there drawings? A thermal camera may be useful as it is winter.

 

I would investigate the roof and walls. I would do the roof investigation from above or through the side of a skylight, as it may be possible to insulate without getting into replacing the internal ceiling. Done carefully you may even get to reuse the corrugated sheet. For that I would say new corrugated will be £700-1000 for the material if you went for the thicker sheet with Plastisol.

 

For the floor, if you are really on a budget it may be that "skirt" insulation around the outside may be a good idea. ie 200mm EPS down the inside of a French Drain to teh base of your foundations rather than digging huge holes inside.

 

I would heat it tactically as needed with a heat / cool split air con unit, or even radiant wall mounted devices.

Ferdinand

 

Edited December 20, 2019 by Ferdinand

[Ferdinand]

3 hours ago, Ed Davies said:

Is that a conservatory from the planning/building regs point of view? I thought they needed more glass in the roof to count.

 

This is a good point. I would just do this one, rather than ask.

 

"Running repairs, Guv'nor"