Advice needed re heat retention issues in an extension

If it cannot retain the heat it would suggest lack of insulation or to high an expectation (and perhaps lack of heat input) 1996 spec?, Velux windows allow the summer sun to beat straight in and give the greenhouse effect (as per conservatories) Re the summer heat put blinds on the velux (anti heat). Unless you actually know what insulation is there its hard to suggest a way forward other than overboarding the ceiling with Kingspan (thickness??) but then there is the extra load issue to consider and other construction issues

 

You say it was a garage before. Was it demolished down to foundations and rebuilt or was it converted for habitation? What kind of roof does it have ? Flat or sloping. It may not have a loft but does it have a hatch ? Finally, did your solicitor supply any paperwork from building control ?

 

If the extension was built in 1996 there probably isn’t any insulation anywhere.

If you want to address it properly it needs a thorough overhaul which really means re building the inside.

 

You will have insulation if done properly to standards extant in 1996 but rather less than current requirements.

You need to investigate. but high ceiling won't help the cause

 

Insulation standards were first created in 1965 and subsequently amended in 1976, 1985, 1990, 1995, 2002, 2006 and the latest in 2013. That means it will have some but not to the latest standards. To give you a gauge, current standards require 10x the insulation required in 1965.

your insulation may have been poorly installed or possibly damaged by ingress of damp etc.

Standard and quickest solution is to view the heat loss via a thermal camera to understand the areas with high loss. You can hire these from tool hire shops. Once surveyed an action plan can be created.

It’s best to do this now with heating still on and days still cold.

 

I can save you the bother, I've got a thermal imaging camera and I do insulation all day long.

You've got hardly any, and what you have got is badly installed, because no one cared about it when it was done.

So you need to move on from that which pragmatically means taking it apart, re building the cold roof with insulation between the rafters dealing with ventilation and then going over it again because you can't get enough between the rafters and you also need to deal with the thermal bridge the rafters create.

Then you need to look at the walls and floor.

If you want to deal with it properly then its expensive, and 90% of people don't do it when they realise how expensive it is so you might want to thing about what your budget is and make a decision about just living with it vs taking the project on.