Start of a long journey

[G51]

Right at the beginning of a what will inevitably be a long journey.

 

About to move abroad for work, but we come back we will be looking to be our first self build. Having already done some reasonably sized DIY renovations in our current house, I am beginning to do the relevant research to be in an informed position to start a self build.

 

We will be looking to make it to the PassivHaus standards, and I am big into my tech so will be looking to integrate a lot of 'smart' home features. 

Currently have a lot of this, with ASHP, solar, batteries, automatically controlled zoned UFH etc so not brand new to all of it, but I have been lurking and reading up on other users success (and failures!) to hopefully try and learn and avoid some of the common pitfalls. 

 

G51.

[-rick-]

Welcome!

 

Reguritating some of the things I've learned by reading BuildHub over the last year or so, search the site for more details:

 

If you build to true PassivHaus standards then you won't need much heating. Sometimes on the internet you see people saying don't need any at all but the consensus here is that you do need something, whether its worth the expense of a big complicated system though is doubtful. So think in terms of keeping things simple and the house at one consistent temperature (no zones). With UFH in a PassiveHaus the floor will never feel warm as it won't be running hot enough. Using UFH to provide mild cooling is possibly a bigger reason to get it than for heating.

 

As far as smart stuff goes, try to think in terms of an add-on layer that all basic functions will continue to work without the smart stuff. You want the main services to work reliably (and have the ability to call out someone to fix them if say you aren't around but family is when something breaks).

 

While many self-builders think of the project as a forever-home/once in a lifetime thing, life does tend to throw up curveballs so always keep in mind that you might have to sell it at some point. So avoid doing things that would put potential purchasers/mortgage companies off.

Edited Monday at 21:37 by -rick-

[G51]

25 minutes ago, -rick- said:

Welcome!

 

Reguritating some of the things I've learned by reading BuildHub over the last year or so, search the site for more details:

 

If you build to true PassivHaus standards then you won't need much heating. Sometimes on the internet you see people saying don't need any at all but the consensus here is that you do need something, whether its worth the expense of a big complicated system though is doubtful. So think in terms of keeping things simple and the house at one consistent temperature (no zones). With UFH in a PassiveHaus the floor will never feel warm as it won't be running hot enough. Using UFH to provide mild cooling is possibly a bigger reason to get it than for heating.

 

As far as smart stuff goes, try to think in terms of an add-on layer that all basic functions will continue to work without the smart stuff. You want the main services to work reliably (and have the ability to call out someone to fix them if say you aren't around but family is when something breaks).

 

While many self-builders think of the project as a forever-home/once in a lifetime thing, life does tend to throw up curveballs so always keep in mind that you might have to sell it at some point. So avoid doing things that would put potential purchasers/mortgage companies off.

Thanks - my first thoughts on heating/cooling is UFH downstairs and fan coils upstairs for that exact reason. I will keep reading and I am sure I will flip flop opinions many times yet - but I am starting now with a good couple of years before I break down so hopefully I can get to a good place before I begin. 

And yes - I have actually done two iterations of 'smart' homes, very much agree, a 'smart' home should be such that your Gran could walk in and use the house as intended without needing to learn anything, and not accidentally turning anything off stopping anything working.

 

My lights currently are all wired directly back to latching relays, controlled both by non latching light switches and a microcontroller/relay setup for this reason.

[-rick-]

24 minutes ago, G51 said:

My lights currently are all wired directly back to latching relays, controlled both by non latching light switches and a microcontroller/relay setup for this reason.

 

Would you mind sharing more about this? I haven't got this far yet (automation is one of those tasks I want to leave until much nearer the time) but this does sound somewhat along the lines of my thoughts.

[nod]

I completed  the plastering and framing on a 2000 m2 weekend place in the lake district About five years ago He filled this with every smart device that is out there Some tgat gadnt even come to market Hes a real techi and own the largest electrical and fire alarm company in the UK 

But concedes that he hardly uses any of it 

If you have an unlimited budget like him Then load it up But in my experience the bells and whistles are usually the first casualty in a spiraling budget 

[jack]

15 hours ago, -rick- said:

So think in terms of keeping things simple and the house at one consistent temperature (no zones). With UFH in a PassiveHaus the floor will never feel warm as it won't be running hot enough. Using UFH to provide mild cooling is possibly a bigger reason to get it than for heating.

 

Hopefully most people no longer suggest that a PassivHaus doesn't need heating. It certainly needs less heating, for less of the time.

 

When it's very cold outside (near or below zero) for long periods, the weather compensation means that our floor does feel slightly warm underfoot. It's nothing like the warm/hot feeling you get underfoot with UFH in a house with less insulation, but I find that sort of heat very uncomfortable.

 

It's also important to understand that a house with PassivHaus class insulation and airtightness is not necessarily a PassivHaus. While our insulation and airtightness are PassiveHaus class, I suspect that we wouldn't meet the full formal specification. The shape of the house isn't ideal. We have a lot of glazing in places and several north-facing windows probably need to be a lot smaller. I therefore find that our heating comes on earlier than many others with similar levels of insulation and airtightness.

 

That said, we use less energy to heat this 290 m² house than we did to heat the 90 m² bungalow it replaced, and we're a lot more comfortable, so I'm not complaining!

 

15 hours ago, G51 said:

automatically controlled zoned UFH

 

I'm sure you've spotted this in your research, but zoning generally isn't needed in a PassivHaus class house. Most on BuildHub with that sort of insulation run their entire downstairs slab as a single zone with a single thermostat. Some temperature variation can be achieved in different rooms with UFH pipe spacing, with fine tuning done by manually adjusting flows at the manifold (no need for electronic controls).

[Marvin]

We have challenges with over heating when the outside temperature is above 11C.  Thank god my wife insisted on openable windows.

 

With two of us in a 104m2 bungalow, when were cooking or washing or my behaviour is being discussed the building usually over heats without putting the MVHR on boost and or the windows being opened..

 

M

[Alan Ambrose]

>>> or my behaviour is being discussed

 

😁

[mjc55]

I know it is a personal thing but I really don't get this "windows and doors closed" idea.  We have slept with our bedroom window open, whatever the weather for close to 40 years and do not wish to change this.  I have heard the argument that with MVHR the air is fresh so why open the window but it doesn't compute with me.

 

We went to see someone last year who had built a 'passive house' (although I don't think it was certified) and they did make a big fuss about keeping windows and doors closed, to the extent that we had to more or less creep in.  They have no UFH and when we stayed for a few days early last year the ambient temperature was great.  It still felt a little stuffy in the bedroom though.

 

We fully intend for our house to be as passive as possible but still intend to install UFH. 

[joe90]

10 minutes ago, mjc55 said:

We have slept with our bedroom window open, whatever the weather for close to 40 years and do not wish to change this.

Then don’t, it’s a personal thing, but you will pay more for heating as your fresh air is colder. If you need to up the flow rate to meet your needs then by all means do that. Jeremy Harris years ago did experiments on different levels of ventilation, window open no MVHR, windows (plural)open no MVHR, MVHR only and measured PPM of co2. His conclusion was MVHR gave a more even rate of ventilation which with open windows was very variable depending on wind speed and direction and in so doing required less heat input (and the air was filtered.) don’t get me wrong I love having windows and doors open (in warm weather) and think MVHR should be controlled by air monitoring, a bit like thermostats control whether heating is needed or not. One person at home, MVHR not required , two or three people at home MVHR on trickle, having a party, MVHR on boost, all controlled by co2 monitoring. (Or by monitoring moisture levels which are also an indication of CO2 levels. The last few months I spent in my build during a hot summer i turned the MVHR off and was venting the house at night through open windows and closing them by day. 

 

13 minutes ago, mjc55 said:

they did make a big fuss about keeping windows and doors closed, to the extent that we had to more or less creep in. 

Sorry I don’t get that.

[SteamyTea]

Welcome.

 

The adding of 'tech' is often misunderstood.

There is the hardware i.e glazing, heating, lights, security.

Then there is the control of it, i.e manual, semi-automatic, automatic, remote and/or local.

Finally there is the monitoring, i.e. remote, local, just data  data and control.

 

Most end up with a basic heater and an adjustable weather compensation controller.

Not enough people collect and analyse usage data.