G and J

A lifetime mortgage is for us wrinklies. No monthly repayments, interest charges roll up and it’s only repaid when the property is sold on death of the last surviving mortgagee (or them going into care). A fab way of funding growing old disgracefully if one doesn’t care how much of a financial legacy one leaves behind.

That’s very kind of you to say. Behind that little row of houses is a quiet little area of back gardens which I’m hoping will prove a lovely place to be whilst still being in easy walking distance of more cafés than one can shake a loyalty card at. We've engaged a company called Vantage. They were recommended by our architect and I have spoken to a couple of the inspectors and they seem good, practical guys to work with. They’re currently looking at our plans so we’ll see what comes back.

After reading your stuff about it we did try doing the future homes spreadsheet. Now we are doing it very strictly and we could not get the results thing all ok. We do have some fixed windows, and from memory one of the issues is that the patio doors aren’t in a huge room, so proportionally it appears on the spreadsheet to be too much. However, I’m now scratching my stubble and thinking, ‘ok, maybe I’ll try this again’….

If you are staying at the house for a good few years fit a Clearview Pioneer, expensive but brilliant. I've owned 3. It's small enough to not need a vent, and it will reduce wood usage massively. The payback will be a couple of years but you'll be up and down to load the fire a lot less.

Quick thoughts.....what does your local planning guidance have to say on the subject of infill or within/without village envelope/boundaries.....where does your house fall? Also does your planning authority have a "cluster policy"? Maybe unpalatable but I've seen situations such as this where a small development of houses is allowed around an existing house with one larger plot to be retained for a singleton property. Some friends did this but it was a long haul to get through.......

I think the actual overheating issue is exclusively me, under the collar, when I contemplate the box ticking exercise that really is a sledgehammer nutcracker. We are aiming at nicely airtight as we will have MVHR, but our insulation levels are modest (for a number of reasons more or less building regs in fact). Our design has limited amounts of glazing, but it does have a 4m wide patio door at the back. We can’t use the simplified method, as we can’t claim blow through and the patio doors blow it for one room. So we are required to do the dynamic method to prove the bleedin obvious, but rules is rules. Here are the elevations. In glazing terms it’s not exactly Crystal Palace is it?

Did you get your doorbell sorted? If not, I saw this and thought of you….

We’ve just submitted our design for building regs approval. Our BCO has agreed that we can use PHPP to demonstrate that our design won’t overheat and thus is ok with part O. I think PHPP 10 is the latest and will cost me somewhere between £200 and £250. Is this what I need to purchase? Or do I need other bits too?

Option 3, treble MVHR extract vents over stinky bit? Option 4, cook stinky stuff in utility room, (trendily renamed ‘spice kitchen’) and open the window…. I'm building in option 5, cook stinky stuff in spice kitchen (see above) and have a closable inlet and extract just for that room.

Re Lewis decking and screed upstairs, I really, really hope that’s not needed as I’ve not designed anything like that in. Most peeps manage with just posijoists and caberboard methinks. But then, there’s just the three of us (one little dog, one grown up, and me) so maybe the requirements are less onerous.

Ta. I had that option and was nervous about bounce so I’m designing in a sleeper wall so our max span is 3.7m.

@Iceverge is your preference for EPS over PIR primarily due to environmental or other considerations?

My understanding is that there isn’t a huge airflow typically below BnB floors, the vents are more to prevent gas build up than humidity control. On the build of our current house we switched last minute to BnB as a land drain was discovered where the house was going, although we diverted it to where it was supposed to be on medium elasticity clay it still meant BnB was cheaper than continuing with a solid floor. On the new pad we’re going for them as the slope is such that at the back of the house we’d have to dig down circa 700mm and then put lorry loads of stone is to build up, on a sight where we can’t bring in a tipper. With BnB we cart a lot less away. There’s also no need for a BnB floor to be any higher than a solid one as long as you are happy to dig down a bit to get the void under (opinions appear to vary between 150mm min and 225mm min. In our case we might have to push some soil towards the back of the house, but that’s it. However I’d go for solid if I didn’t need BnB, but I think it’s potentially a ‘save having to think’ option for an architect.

On the brightside, if you did have a problem at least you would know about it as your socks got wet through when you walk into the utility room.

Oooh you got a blank look from Iceverge lol What was you largest span?

Thanks folks. It seems to me the risk vs benefits don’t look good for our build. I’m not as brave as JohnMo. So it’s back to either a temporary floor or simply sticking with a standard bnb floor.

I’m assuming that the network is the balancing item/buffer in the system. Sizing for max need may incur a lot greater cost than is economically sensible.

Accepted that the primary role of the VCL is to keep moisture out of the structure, in our case a standard 140mm stud based OSB skinned timber frame. But I am working on the notion that from floor to ceiling VCL, with wall VCLs joined by Tony trays, is effectively a balloon with as few penetrations as possible. At all points those VCLs are sandwiched between either OSB, plasterboard or insulation, so there should be no possibility of ballooning.

Ouch. Hadn’t thought of that. I’m going to have a long pipe run from ASHP to UVC so that might require some thought. As it will only happen when I need cooling - therefore on warm days - maybe it’s not an issue but a simple delay on the 3 port valve might sort it.

That’s the bit we are worried about. Others on here having described using pipe temperature sensors to control the fan on the Fancoil in what sounds like a relatively simple and elegant set up. I think our FC will be used for cooling only, in which case the fane will only come on if the room controller says ‘cool me’ and the pipe sensor says ‘I’m just soooo cool’. Hopefully that will mean that the ‘burp’ of unwelcome hot or cold from the FC will be minimised.

I’m having an insulated beam and block ground floor. I’ll happily set out my reasoning if peeps are interested, but…. What downsides are there to putting in the insulation/dpm/UFH/concrete screed from a lorry before I build me walls? The fibre reinforced sand and cement screed can be poured from a lorry and once cured it will give us a good base to build off of. It’s not my original idea, I stole it from a buildhub stalwart, but I think it’s a good one. But practically, what issues might it cause?

It’s a bit like alcohol and sound logic. Both exist but not at the same time. In our case we might use spare solar power directly to heat the water when the sun shines and we need cooling. But we might not, we might just use schedules to have a blast of hot water (should be reasonably efficient on a warm day therefore not take too long and still have a decent COP), and then run on gentle cooling the rest of the day. At the mo I think I’ll be wiring to allow the installation of a solar diverter but start without one. Less (kit) is more (money left in the piggy bank). Or maybe less (kit) is less (balance on the mortgage).

Not finally, as we won’t be buying them till next summer at the earliest and availability changes and new stuff is launched. I’ve been working on the premise in various design areas that by finding one solution that is economically and technically viable, and allowing for the requirements that that option requires, we have a base case which we may be able to improve upon when the time comes to order. I’ve been looking at Reverso units, which seem a sensible design and cost.

Maybe they spent so much on the build they can’t afford heating lol Being serious our design started timber frame and no masonry skin. We did a good few hours research and concluded that at least a partial masonry outer skin increased the number of normal mortgage lenders (and we think house insurers) which would accept our house, and more importantly for us a significantly greater number of lifetime mortgage companies which would accept our house. We changed our design to just over 50% rendered block as a result. We will never know whether it would have caused us issues….

We’ll be running drain pipes to our Fancoil locations in case. The cost of a bit of pipe for first fix is tiny. The hassle of doing it later is huge. However, to get lots of supercool from our fancoils I’ll need to zone them and that won’t be day one, we’re going to try using them above the dew point. (Crumbs, I almost sound like I know what I’m talking about!)