Wondering whether to make the leap

[v4169sgr]

Hello all and what a wonderful bunch of peeps you are !

 

Long time lurker taking first unsteady steps. And also complete cack-handed airy fairy impractical nincompoop with nary a chance of getting any DIY right. To give you an idea, re-hanging a door took three attempts to get it almost slightly better than it was originally. Common sense: reading empty. People skills: flatlining. A right idiot in need of education.

 

But! I am cursed with ideas! So, here goes.

 

Looking at a PH single storey construction, common envelope with two living units, wrap around BIPV solar glass (opaque walls as ventilated facade, solar tiles etc), salt water batteries with hydrogen as back up, GSHP vertical borehole supplying heating cooling and potable water. Live in one unit (3 bed), granny annexe or self catering let in the other (1 bed).

 

A bit of savings in the bank, and taking a long look at a specific plot in East Anglia. Edge of village location, just less than 1/4 acre. Good road frontage, easy access, services available if desired, dark skies ( ), OPP for something completely different won on appeal. Lots of opposition rightly so to opportunistic developers proposing massive housing estates, lots of pressure on local services (run off & foul water, doctors etc). Would be a big ask, a huge risk, and would clean me out. Looking at selling up here, moving up & renting, and using proceeds to finance the build, starting Q4 2018 or Q1 2019.

 

Trying to decide if this is a good opportunity to get started now and sort out the detailed PP, or walk away and look for something closer to the time.

 

Primary motivation: financial in the long term, to reduce outgoings.

 

I suppose at the end of the day only I will know how much of an utter idiot I am being

[Tennentslager]

opaque walls as ventilated facade

What's that mean?

And how come you chose your car registration as your username thingy???

[MikeSharp01]

Welcome.... Sounds like a great idea. 

[Triassic]

It really is down to location, is this a place you are happy to live? Have you a support network locally, 

 

regarding the house, keep it simple, timber frame, insulated foundations, insulated walls and roof, solar panels (if you must!) ASHP for the heating and hot water. 

[ProDave]

I don't know what house prices and plot prices are where you are looking, but few of us would advise a self build as a way to get a cheaper house, unless you can do a lot of the work yourself.  Rather it is a way to get the house that you want, built to the standards that you want, rather than a builders off the peg standard box.

 

You don't need to jump through all the hoops and pay fees for a house certified as a PH. Many of us are just building very well insulated, well sealed houses that we know will be very energy eficcient without having them certified as such.

[gravelld]

I think a GSHP is overkill if you're building to Ph levels (not necessarily certified). Part of the point of Ph is it can make a building and its services simpler.

 

You might be able to get away with a couple of Argos plug in oil filled rads.

 

For DHW, solar, immersion, maybe inline modulating heaters.

 

For cooling, design the shading correctly.

Edited August 23, 2017 by gravelld

[Nickfromwales]

If the two properties will never be divorced, I'd say heat with gas and have one boiler servicing heating and DHW for both units, or a bigger ASHP doing the same, with a single unified heating / DHW setup. Lower capital outlay and you could easily split them later if so required with a bit of thought in the plumbing layout now. 

Oh, and welcome. !

 

[gravelld]

A gas boiler is also probably overkill for space heating, although it could be an expedient choice wrt DHW. There's also the "whaaaaa?" factor us Brits have confronted with a properly built house which might not need a boiler; this can affect resale value as commonly discussed here.

 

You say lower capital outlay but it's still a lot more than plug in heaters and an immersion coil (and if PV panels are going in anyway...).

 

A lot might depend on the DHW demand.

[Nickfromwales]

Rental appeal is not at its best when people see little electric panel rads TBH, even though they may be more than adequate when used in conjunction with a timeclock. If a communal system is used then the property with the least space can be plumbing-clutter free, but that could also easily be acheived with an electric shower, and an small electric water heater ( if no bath ). 

Best to remember that an UVC can be purchased to lay flat ( horizontally mounted, and purchased specifically ) so can be hidden in very little attic space. Boilers can go in the attic too with a vertical flue.

Gas would be overkill if it were one system for each unit, but it is undeniably simple, widely understood, effective and efficient to boot. 

@v4169sgr, is grid gas available ?

Also, tell us your name ??!!!!

[Jeremy Harris]

Sounds a very challenging set of goals, be interesting to see how you get on.

 

I've been trying to buy some BIPV glazing for over a year now, with no success, as I want to add a BIPV glazed walkway down the side of our build.  There's lots of "new product" guff around, but frankly it doesn't seem as if there is much in the way of a supply chain that's actually retailing the stuff, at least not at affordable prices.

 

The second point is the borehole.  We have one, and there are some pitfalls with trying to use the same borehole for both potable water and as a GSHP (more accurately a water source heat pump) collector.  Obviously you cannot use a conventional down-hole collector, as that would make it impossible to also fit a submersible pump.  That means looking at using a standing column collector, and there are several problems with that in the UK, not least of which the fact that there were no UK companies who had expertise with this technique - all were only familiar with down-hole collectors.. 

 

The first is that the EA classify a standing column collector as "abstraction", even though the water is going back down the same hole.  That means getting an abstraction licence, as you'll almost certainly be pumping in excess of the 20,000 litres per day at times.

 

The next is that you will have to convince the EA that there is zero chance of accidentally contaminating the aquifer with the pumped back water.  I couldn't find a way around this, as they wanted certification that there was no way that the water to refrigerant heat exchanger in the heat pump could fail and contaminate the return flow.

 

There is also the power that the water pump draws, in order to supply the heat pump.  A standing column system uses a circulating pump on the primary that will draw around 500W or so, which hits the COP of the heat pump pretty hard when it's running.

 

Then there is the issue of having to fit filters in the heat pump primary, in order to keep the input plate heat exchanger free from blockages by sediment, etc.  These filters need regular (6 monthly) replacement, adding to the maintenance burden and cost.

 

Finally, all the pipe work from the borehole to the heat pump needs to be frost protected, as it may be subject to sub-zero temperatures when the heat pump is off and the weather is cold. 

 

As someone with a lot of hard-won experience with boreholes, I would try hard to avoid having one if you can possibly get a mains water connection.  There is a constant cost in maintaining and running a water supply borehole, that comes close to the cost of mains water, in practice.  If the water company eventually decide to run a main down our lane then I will connect to it and abandon the borehole, for sure.  The only reason we have a borehole is because the water company wanted £24k to run a pipe down the lane.  For heating and hot water pre-heat we have an air source heat pump.  Massively cheaper than a GSHP, and not significantly worse in terms of performance.  I think I worked out that the extra capital cost of having a GSHP was many decades of ASHP operating cost difference.

[reddal]

I have a GSHP connected to boreholes that also supply water.

 

However for reasons Jeremy describes - it wasn't simple to use the same borehole for both - so we ended up drilling seperate holes - which was obviously expensive.

 

If you have to drill a borehole to create a water supply - and you are decided on a GSHP, then it might make sense to drill another at the same time given a lot of the cost is in getting the equipment onsite and setup. i.e. the extra cost of another borehole might be something like £6k, which might compare well to the cost of installing a near surface loop, and deliver slightly better performance.

 

If I was doing it all again I would think very carefully about options other than GSHP - it ended up costing a lot.

 

The one thing a borehole based GSHP does probably better than other solutions is passive cooling - which is what persuaded me to go down that route. However the extra cost would have paid for a lot of other cooling options.

 

Good luck!

 

- reddal

[Ferdinand]

Where are you in East Anglia, roughly?/ And which Council area you are in?

 

If you are renting one or part out, your very best guarantee of success is to be within walking distance of a <60 min train journey to London.

 

Wrt to this plot, you need to go and see local letting agents information and find out what rents for how much in that place, what it costs to rent one out, and what the demand is for. And who is your target market. Without at least that you are just playing Pin The Tail on the Donkey. 

 

Then you are in a position to identify your gross and net returns, which means you can then make a sensible decision.I have not started building rentals, but I plan to start in the next years - I will be targeting build cost including plot and fit-out (not incl. furniture) in the £90-120k ballpark. I have no idea whether I can achieve this (yet) with target rents of perhaps £700-750 a month. Even that is a low return compared to what can be achieved with refurbs but I want to do some newbuilds and see what is possible.

 

You will need something attractive with no showstoppers for your target market, and something that works to keep them there for 5+ years. And something SIMPLE and ROBUST so you do not spend your weekends mending or tuning it.

 

Tenants will be best with a single cordless controller in a house which is warm throughout with bills of <£500 per annum, annd never needs anything adjusting. Unless they are eco-boffins they will not give a hoot whether it is certified or not.  And eco-boffins tend to have built their own eco-houses or want to do so and so will want to be moving on from yours not staying in it.

 

Ideally the whole house should have zero moving parts an nothing to break down, but many are incredibly suspicious of electric heating.

 

The need to exclude complication is one of the biggest lessons we are learning collectively here.

 

And do not underestimate the amount of management involved in rentals - especially holiday ones.

 

Ferdinand

 

 

Edited August 23, 2017 by Ferdinand

[ToughButterCup]

20 hours ago, v4169sgr said:

[...]

Primary motivation: financial in the long term, to reduce outgoings.

 

If outgoings reduction is the real end in mind, and you can make a compelling evidence-based case for doing so, there is no question.

The only thing to worry about is your evidence base.

 

If you are certain of your facts, Just Do It.

[v4169sgr]

Thank you all for your wonderful replies - I feel quite humbled. And 100% my fault for being so terse I generated a few misunderstandings - sorry !

 

@JSHarris I've been talking to Onyx Solar [ 

http://www.onyxsolar.com/ ] . They supply world-wide, and were happy to talk to me in the context of domestic / residential, even though the majority of their work is much larger scale. Unlike quite a lot of the 'near market' stuff we hear about, they've got an extensive back catalogue of finished installations. Attraction for me is they could supply BIPV windows, roof tiles (made to look like red clay pan tiles) and opaque BIPV glass for ventilated facades (note @Tennentslager ).

 

My handle is astro-related, not vehicular. Enterprising detectives might use this route to un-mask me !

 

@Triassic You are right. I don't have much of a network here (read above for socially inept ) but am confident that new circumstances and activities will bring their own rewards, via astronomy, agro-forestry and social action interests, providing only that I make a go of it.

 

@ProDave I agree with you: I am not likely to save money on a custom build. @recoveringacademic is exactly right and understands me well. Within reason, I am exchanging higher initial capital costs for lower outgoings in the future, coupled with as much independence from utilities as possible as a hedge against future instability. Even to the extent of not paying particular attention to payback periods, ROI calculations etc.

 

It's the evidence-based case that bothers me at the moment. No point in wishing on the moon if I am not likely to be in a position to achieve it. And I have significant responsibilities I must continue to fulfill (two older teenagers needing a base, father who is not getting any younger, etc)

 

@gravelld: I've actually had initial feedback from one firm of architects that three significant trees just to the S of the plot, in combination with a single storey build, might make PH unachievable, if built on the existing OPP footprint, elongated N-S. However from what I understand, cooling PHs is more of a challenge than heating them. DHW could be immersion during high insolation months and HFC CHP during the winter.

 

@Nickfromwales and @Ferdinand: My apologies for misleading you. The granny annexe could also serve as a short term self-catering holiday let of one double bed self-contained accommodation within the single building unit. Relatively easy entry into this market: a fire inspection (recommended anyway!) and some understanding of customer service and market research, coupled with a willingness to hire and pay well a cleaner on a changeover day. I'm looking at Green Tourism accreditation as a way in. The plot is right next door to an established mid sized country hotel, though, which could make life interesting!

 

I would definitely not be in the long term rentals market, and nor do I have the slightest interest in resale value. This is an extremely long term commitment for me.

 

And shared facilities is definitely the way to go: one MVHR & one heating + cooling + water system for both main and annexe.

 

@JSHarris and @reddal Thank you kindly for your testimonials about GSHP. Per the above, ROI is not what I am looking for. I thought though that GSHPs didn't involve refrigerated coolants, and were water: water. I am looking at open loop systems such as http://www.synergyboreholes.co.uk/geothermal_boreholes/index/open-loop/ and http://www.soloheatinginstallations.co.uk/ground_source_heat_pump.htm . How much would you pay for filters in the heat pump primary? Would this be of the same order of magnitude as filters I understand the MVHR would need?

 

Open question: the local sewer mains is 150 mm piping which according to local residents has already blocked twice in a year, but Anglia Water say it's just fine to add another 35 houses to (! ). But the site is on the boundary between groundwater protection zones 2 and 3. Service connection to main sewer, or sewage treatment plant, like http://biorock.co.uk/ ?

 

I'm sure I must have missed loads, but it's late, and there's plenty other chances!

 

[ToughButterCup]

1 hour ago, v4169sgr said:

[...]

Open question: the local sewer mains is 150 mm piping which according to local residents has already blocked twice in a year, but Anglia Water say it's just fine to add another 35 houses to (! ). But the site is on the boundary between groundwater protection zones 2 and 3. Service connection to main sewer, or sewage treatment plant, like http://biorock.co.uk/ ?

[...]

 

If they are saying that, sing the Hallelujah Chorus.  No poo disposal no house. Its that simple,

[Onoff]

Dark skies? Here's one I made earlier...and FINISHED!

 

 

 

I'd post more pics but they were on Photofucket before it got all restrictive to 3rd party links.

 

 

Edited August 24, 2017 by Onoff

[ToughButterCup]

See, told ya! If you sing the Hallelujah Chorus @Onoff performs well.

 

Even if he did half inch his best mates post knocker to do so

[ToughButterCup]

On 8/24/2017 at 00:21, v4169sgr said:

[...]

It's the evidence-based case that bothers me at the moment. No point in wishing on the moon if I am not likely to be in a position to achieve it.

[...]

And I have significant responsibilities I must continue to fulfill (two older teenagers needing a base, father who is not getting any younger, etc)

[...]

, and nor do I have the slightest interest in resale value. This is an extremely long term commitment for me.

 

You are in the risk reduction game. The evidence base does not have to be perfect, but you do have to have a clear tipping point. A moment you can without too much financial damage simply stop.

 

If we were to do that now, it would be very damaging indeed. But how many thousands spent working out how far to go down the runway before aborting the take off is a matter for each individual.

 

Never underestimate the determination of a committed self builder. Get all the family onside if you can. Network like hell. Go down the pub and listen to the response you get from those whom you trust when you tell them you're thinking about it. "Ah, I've always wanted to build my own house [....] It must be brilliant to be able to even think about it"

 

Don't underestimate  the huge amount of support you'll get here. This group of people has  saved us many thousands of pounds. Emotional, technical, hysterical, and then of course there's plumbing. We apologise in advance for @Nickfromwales. He's tame really

[Nickfromwales]

[Jeremy Harris]

7 hours ago, v4169sgr said:

 

@JSHarris and @reddal Thank you kindly for your testimonials about GSHP. Per the above, ROI is not what I am looking for. I thought though that GSHPs didn't involve refrigerated coolants, and were water: water. I am looking at open loop systems such as http://www.synergyboreholes.co.uk/geothermal_boreholes/index/open-loop/ and http://www.soloheatinginstallations.co.uk/ground_source_heat_pump.htm . How much would you pay for filters in the heat pump primary? Would this be of the same order of magnitude as filters I understand the MVHR would need?

 

 

The synergy system is a variation on the standing column system, first used in North America, but it has been falling out of favour because of the poor efficiency.  Here in the UK the EA have a potential problem with it, as they considered the pumped water to be abstraction when I asked, and that meant an abstraction licence and all the associated cost of ensuring that there was no potential aquifer contamination.  I talked at length with the EA around 5 years ago about this, as I wanted originally to fit a small "shoebox" GSHP, run like this.  The massive cost involved, together with the hassle, put me off.  Our ASHP was less than 1/4 the installed cost, and performs better than a water source standing column heat pump.  The main reason that the water source heat pumps have poorer performance, when used in the standing column/open configuration is the power needed to pump the water up from the source borehole.  This will be between 500 and 1000 W, and so makes the overall COP of the system pretty poor.  The down-hole collector systems do not have this level of primary circuit pumping power, as they are closed loop, so just have a much lower power circulating pump, that's about the same sort of power as the fan motor on an ASHP.  The primary circuit filters are a minor cost for a water source heat pump, perhaps £50 a year, so pale into insignificance compared with the other running cost and regulatory hassles.

 

If you need to have a borehole for water, and wish to spend a lot of additional money to have a GSHP running from a borehole, then the best way to do it, without question, is a system like that which @reddal has.  At least 25% of the cost of a borehole is associated with the initial mobilisation and fixed cost elements, so boring two holes on site, one for water and one for a GSHP collector,  is a better bet.  The cost of drilling a hole, fitting a down-hole collector and grouting it in place will be lower than the cost of drilling, lining, grouting, fitting a submersible pump etc for a drinking water borehole.

 

We've been living with a cheap (around £2200 DIY total installed cost) ASHP for a while, and it is very efficient, around an average COP through the year over well over 3.  Had we fitted a GSHP with a down-hole collector in a second borehole then we would have been looking at an installation cost of over £10,000.  The extra £8,000 or so would have never been recovered, and would have been a pointless expenditure.  The annual running cost saving by using a GSHP, rather than an ASHP, would have been around £40 per year, at the most, for us so the payback time for the additional £8,000 capital expenditure would have been a couple of hundred years.

[SteamyTea]

I think to be fair to borehole GSHP systems, they are not really suitable for relatively small, low energy housing, thy don't downscale well.  They are more for large US/Canadian style housing, possibly with a swimming pool too.

 

[v4169sgr]

Thanks a lot for the additional feedback.

 

@recoveringacademic: Thanks for the encouragement. Indeed discovering the right questions to ask and then deciding how to analyse the answers is  half the battle. Time waits for no man though: wait too long and the opportunity will be gone anyway. It's just a question of whether I'd be glad to see it go, or not I've decided to see if there may be an opportunity to acquire some additional land to one side of the plot, as right now things seem to be rather constrained, and architect contacts get cold feet rather quickly when they try to square away what I am looking for versus the constraints of the site as it stands now. This will depend on the outcome of a planning appeal on that land becoming known, however.

 

@JSHarris Thanks for the additional comments. I didn't really want to turn this thread into a rehash of the relative merits of GHSP vs ASHP, and am not strongly tied to one solution or other, but would like to maximise independence from utilities, if it seems practical to do so without sacrificing the opportunity to build the house in the first place. One thing I am deeply conscious of any future dwelling is that it should be a very low noise environment inside, and by that I mean eliminating buzzes, hums, etc as far as possible. I have a family member who can hear and is bothered by the noise of low energy bulbs (not LEDs!). So, doesn't your ASHP make a noise like an extractor fan? And what about icing up in winter / COP suffering in cold weather? A key benefit of a borehole GSHP is access to a year round near constant source or sink of thermal energy. That having been said, 0.5 - 1 kWh is a high cost indeed for pumping water up a borehole! How long would one have to run that monster motor per day to satisfy the needs of a typical household's clean water needs (excluding flushes, irrigation etc)?

 

@Onoff Yes, I did say "dark skies" Thanks for the photos: nice plinth! How do you drive your mount? Where's the OTA? And is that a thermal gap you've got there, or am I seeing things ?

Edited August 24, 2017 by v4169sgr

[Onoff]

7 hours ago, v4169sgr said:

 

@Onoff Yes, I did say "dark skies" Thanks for the photos: nice plinth! How do you drive your mount? Where's the OTA? And is that a thermal gap you've got there, or am I seeing things ?

 

I'm NOT the astronomer. That's my big brother...the barrister...the one who could jump on a plane to watch the elipse in the States.

 

I'm the younger, thicker, less successful one, generally not referred to by name by our parents rather as "...the one who likes wood, metal and playing with wires!"

 

OTA's a Celestron something. It's got motor(s) in it is all I know. Will try and find a pic. Thermal gap, wtf? You'll do well on here talking like that!  The plinth is one I copied from photos of an Altair one. I just scaled the photos in CAD and started cutting metal. Sits on a 1200mm cube of mass concrete with a duct for the electrics coming up through into the plinth.

 

 

 

Edited August 25, 2017 by Onoff

[Ferdinand]

1 hour ago, Onoff said:

I'm NOT the astronomer. That's my big brother...the barrister...the one who could jump on a plane to watch the elipse in the States.

 

Yes, but can he build a 14 inch naval gun out of a set of bagpipes and a crate of whisky?

 

[PeterW]

9 hours ago, v4169sgr said:

....am not strongly tied to one solution or other, but would like to maximise independence from utilities....

 

If that is your target then any of the xSHP technologies should be irrelevant as you need to look at removing the heat/cool needs and focus on the fabric. Proper PH design will leave you needing just DHW and incidental heat - a passive slab heated by a Willis immersion (a la @TerryE) will more than compensate for any losses and the slab can also even out any warm spots to cooler areas. 

 

DHW in that case would be down to something with low losses such as a sunamp unit, PV would be preferable but tbh using E7 you will be hard pushed to get the payback if you are at near zero input for heating. 

 

The £5-10k for the xSHP technology buys a lot of additional insulation and air tightness product ..!!