Clark Kent

The wall construction is brick-cavity-brick. The cavity has been retro filled in the past with what appears to be blown mineral wool fibres, there is also a DPC. I don’t really fancy cladding internal walls as well.

I like this idea….definitely more viable than taking the whole floor slab out

Yes I’ve tried to weigh all this up. The stairs are pretty knackered anyway so I’m of a mind to replace completely as I believe that differing height risers may fall foul of building regs, if they looked that closely although I don’t think they will. We’re taking the entire rear wall out for the extension and relocating the front door so that problem is dealt with. I can change the height of the other existing internal doors myself. @joe90 I’m not great with all the acronyms on here, I’m guessing IWI is internal wall insulation though? I was indeed also considering some internal insulation. Need to read a bit more about it though as the little I have read suggests it could cause condensation. I know I could use a natural breathable product but that would necessitate using lime plaster and breathable paints etc, sounds like a PITA. Finding a plasterer that would do it could be difficult and costly. If I were to use IWI on the exterior elevations would any internal walls coming off of that exterior wall become a cold bridge?

@Roger440 I have considered an overlay system. I also had a quote from a firm regarding cutting the underfloor into the existing concrete floor after coming across them at Build it Live. I’ve discounted this option as I think the heat would literally be sucked out of the room into the ground. I don’t know the existing slab build up but I’m assuming it’s concrete slab directly onto aggregate or mud. I’m thinking that due to the worst case of heat loss through the floor perimeter being counteracted by the new well insulated slabs on two sides I might be able to run a 25mm-50mm PIR board over the ground floor under an overlay system. I’ve also read on here 100mm PIR is minimum below underfloor, but then there’s also a post stating that if you were pouring a slab the size of a warehouse there’s no need to insulate the centre as heat loss is minimal. The majority of heat is lost through the floor edges. It’s difficult to know what to do, the salesman will tell you that heat loss is minimal through the floor. A builder friend has laid lots of overlay systems and found them to be very good. I’m sure they work and will keep the house warm but the million dollar question is how much will it cost to run…. I guess the other thing to mention is that we aren’t on mains gas here, so it’s either LPG or electricity. I like the idea of the renewables route but again, I only have a finite budget.

I think more of the case of not looking further than their order books….

It’s funny as when i first started looking into heat pumps and UFH the vendors were all telling me that the least heat is lost through the floor “heat rises-right!” Luckily I’m a tad cynical and started trying to dig down into these claims a bit. I did see this, ideally I would do but tbh financially and the fact that we’re living in the property I can’t see it being a flyer…I’ve considered many scenarios such as sending the family on holiday and doing the work but realistically I don’t think it’d work.

I don’t think that a complete rebuild would be feasible as it’s a semi (sorry forgot to mention that) and we’re in an AONB so gaining planning for anything is a pain

@Onoff maybe it’s a Kent thing….the smell was gopping though. @Roger440 yes, I’ve whittled many an hour away on this forum already 👍🏻 I think the main thing I’m interested in atm is insulating my existing slab, as far as I have read the biggest heat loss seems to be from the edges. I will only have the one (existing) side exposed due to the side and rear extension so I’m hoping this makes the situation a lot better. Digging it out and replacing isn’t really viable.

Hello Been lurking on this site for some time trying to glean information and thought it about time to join in and introduce myself…. We bought our house about 18 months ago in a small village in Kent, it was in poor condition as the lady that owned it previously was a bit of a hoarder and had let it go…but we could see the potential. I’m a keen DIYer, fairly practical so intend on doing a large amount of the work myself, or at least overseeing (project managing as they like to say on Grand Designs). The house has been gutted (mainly to get rid of the smell!) and made liveable to a certain extent, currently our only heat supply is a log burner and some oil filled electric rads that we use if we’re feeling really bougie. The Plan is- Double storey side and single storey rear extension Upgrading existing insulation Replace windows ASHP (maybe) I’d like to make the old part as thermally efficient as possible, obviously financial and complexity will dictate how far I can take this. I’ll have plenty of questions, be kind though as I’m a relative newb to these things and nobody was born with the knowledge