Full house renovation and retrofit guidance

[fisnik]

Hi there.

We're going to do a full house renovation including to the rear and side (2 story wrap around extension) and loft. As you can see from the pictures there's already an existing single story side extension. We'll be adding another level to it on top and extending to the rear too.

All the family will be moving out and the house will be entirely gutted to the brick so it's ideal to install any insulation and whatever else possible to make it as energy efficient as possible whilst the works are being done.

The problem is the budget I was envisaging whilst substantial it will be mostly eaten up by the extension (probably). I don't know how much funds we'll have left to do a lot of the intensive adaptations (like super tight airtightness, MVHR, also dig up the concrete floor and insulate). Getting an idea of what materials and methods and their cost, might help to decide what we should drop out from doing. Current original fabric of the house is solid walls 1930s built.

Just on the face of it what kind of insulation specifically I would be looking at in terms of what materials, internal or external insulation or a combination of both? Although it would be nice, hitting EnerPhit levels I imagine it would probably be too costly and impractical, but I'd like to get some way towards it if I can and if I can do it on the cheap and do some of it myself I'm up for the challenge. Even if it just enough so I can go for a heat-pump and not worry that it's going to cost me more than my current gas boiler in bills. Dream is to have solar, battery and heat-pump and disconnect the gas. (I may need more help later with this aspect later on) 

We're about to re-submit our planning application as we had a hiccup and were rejected, the plans that I've attached are more or less what we'll be ending up with though. I'll still be getting quotes from builders etc but I'd like to have plans in place that include the insulation aspect.

Any guidance is much appreciated.

House extension plans.pdf

[JohnMo]

If you can only afford to do the extension why are planning gutting the house as well?

 

Cut your cloth according to budget.

 

I would have an air test done and ask the guy to spend a hour going around the house finding and identifying air leaks first. Then make a plan of action to fix. Understand your current insulation and see how to upgrade cost effectively. Lofts are easy to upgrade, floor? (New floor or insulation to original), walls? (Internal or external)

 

You plans have zero details on build up of walls, roof, flour etc, so are just a pretty picture. To get what you want the builder needs to quote based on exact specs, hoping for the best isn't going to get what you need.

 

If you aren't airtight don't bother with MVHR, a well designed MEV or dMEV system will be more appropriate. And cost many thousands less.

 

I would step back and get everything planned and realistic to your budget.

 

 

[Redbeard]

Welcome.

 

What's the orientation? Is it conducive to solar? Do you have plans for PV?

 

I assume the house is of cavity construction. is the cavity insulated? If money is tight I am not sure how keen you'll be to completely remove the bays and 'plant' new bays on top of EWI. EWI also needs care to avoid the risk of thermal by-pass via the cavities. 

 

If you were to go for internal insulation (IWI) you'd be limited as to what U value you could achieve, due to the risk of interstitial condensation. Detailing can also be tricky depending on the internal layout. On the other hand, assuming you do not own the land to the right, I'm not sure how practical EWI would be, either. Ideally you need to find a way to use one or the other, or a mixture of both. If perchance, there are 'viable' (50mm+ and 'clean') cavities and they are uninsulated, start with that, with EPS beads (not mineral wool, in my view).

 

 

[Redbeard]

I was typing while @JohnMo was posting. His points are very valid. Why rip out if you cannot afford to re-do? If the potential cost is completely unaffordable why not ask for a staged plan?

[fisnik]

Thank you @JohnMo and @Redbeard for the messages. The orientation is the frontage you see in the photo is south facing. It's nearly perfect south. 

 

Perhaps I should have explained. The house needs "gutting" because everything internally is really old. Artex ceilings, textured wallpaper, exposed central heating pipes, kitchen units falling apart, non existent wall sockets upstairs with old grey style metal consumer unit that is not fit for modern age. It will need full rewire and full new plumbing, new kitchen, new flooring, new everything. 

 

We're a family of five living here with three young children and we need to modernise our home. We bought it with the view of extending. Two of our children are special needs. Our 9 year old son is profoundly Autistic with high needs and will be living with us for the rest of our/his life. We're looking to add a sensory room for him. We will also potentially have grandparents move in once extended as they currently travel in every day to help out with the children and taking them to and from school. Me and the wife are both working full time. That's the reason why we're looking to increase the size of the house as much as we can. Also we need to alter the living space to open plan as we need to oversee the children and have line of sight. Our boy can really go for our toddler if he feels annoyed or any noises are made.  😩

 

In terms what would be a priority is renovation>extension> energy efficiency (insulation, air tightness, solar and battery for bill savings). The aim is to do it once, do it as best we can and we chose to wait and do it this way instead of having a mish mash of renovation and constant upheaval where you're doing a bit at a time. We're lucky that some years down the line after buying we can afford to do this now without putting ourself out financially.

 

The drawings posted are just for submitting planning and not detailed. I will be having detailed construction drawings from my architect once we get the planning accepted.

 

In terms of insulation the only old fabric of the house will be the frontage you see there. and the wall of the existing side extension of ground level. Hoping to do some trial holes and hopefully the foundations are good enough to add the second story on top. The house is definitely solid brick. The existing side extension is cavity wall from the 90s I expect (previous owners built it). I'll have to see if there's any existing insulation within it. I am mindful of this but I'm hoping to fill that cavity with beads. The access road is shared road for garages so strictly speaking I'm not allowed to put anything on the side externally but realistically maybe just 50mm EWI may not ruffle any feathers. The main neighbour that has most of the impact said he was fine with it.

 

From our calculations we have the funds to do the renovation and extension as seen on the drawings and that is the priority. But with what would be left over also we like to get the best cost/benefit analysis in terms of energy efficiency/insulation and eco friendly aspects to our build. Currently we're hoping to not get a loan out but if something is worth is we will.

 

 

Edited 2 hours ago by fisnik

[Redbeard]

10 minutes ago, fisnik said:

maybe just 50mm EWI may not ruffle any feathers.

 

I realise you will probably be there for life, but just in case you ever need to sell, might I suggest that you try to 'buy' that 50mm? A client of mine did exactly that, though they at least knew who owned the land. In the case of a 'shared road' it may not be so straightforward to find the 'owner' to buy from.

[fisnik]

21 minutes ago, Redbeard said:

 

I realise you will probably be there for life, but just in case you ever need to sell, might I suggest that you try to 'buy' that 50mm? A client of mine did exactly that, though they at least knew who owned the land. In the case of a 'shared road' it may not be so straightforward to find the 'owner' to buy from.

I know who owns it. It would be all of the 8 properties that have access to it on the deeds. So I'd need to buy it from the 7 other homeowners. Don't think I'd be able to deal with the paperwork that would need. I was told that apparently you can get a party wall agreement and put all other 7 on it and that "might" be okay but I'm a bit weary of doing that too.

Edited 1 hour ago by fisnik