Central Vacuum

We just decided on another feature in our house, to install a central vacuum system.  This consists of a large vacuum motor in the garage, and ducting distributed around the house.  These terminate into sockets into which you plug a long hose that is the same as any other vacuum (only about 10m in length).

The system activates when you plug the hose into a socket.  This activates the motor and creates a vacuum in the duct system.  There is also a floor pan system for the kitchen, where by you activate the system with your foot and sweep into it from the floor as you would a dustpan.

Its certainly a little bit of an extravagance, but not too much so.  There are genuine benefits to the system, primarily the fact that the really small dust is taken out of the room rather than recycled through the motor back into the air in the room, also the motor is considerably stronger than a standard vacuum cleaner, giving a better clean to the carpet.  You have the less compelling benefit of not having to carry the heavy motor unit around.  All in all it's about even but I think given we have the opportunity to add this in now I'd prefer to do so.

The ducting runs through the finished floor (a sand & cement screed on top of the pre-cast floors) at the same level as the underfloor heating.  We also have to plan to insert runs through the walls and around where the sockets will live in order to minimize the effort of installing the system - with the walls being constructed as I speak we ran close to the wire on this, but with all the other primary issues to get sorted this had to wait until the important stuff got sorted!

You want money?? - Do you think we're a bank or something??

Cash flow is probably the more stressful part of the build in my opinion, all the other choices are positive in terms of how you want the house to look, or last over time, cost, etc but in general are positive, exciting things to think about.  Cash flow however is wondering who, when and how much you have to pay vs what you have in the bank.  No one like waiting to get paid and I resolved at the start to do my level best to ensure people get paid on time and stay happy.

As stated before the mortgage is paid in arrears, so not until we had the 1st stage complete could we start drawing down the mortgage.  Of course the catch-22 is that you don't want to sign any contracts until the mortgage is 100% available.  So in Nov we finalized and signed the loan agreements, with a 90 day period to draw down the 1st payment.  In that time we had to pick the builder, finailze the price negotiations, find a digger, wait for weather, etc.. but it was more like 6 mths before we were ready to draw down.  In that time we contacted the bank a number of times to ensure that the offer was still good, and if not is there anything we need to do.  All was well.

Until we needed the money that is.  Now the loan offer needs to be redone from scratch.  For anyone who has got a mortgage before there is a lot of documentation that needs to be assembled, all of which cross-confirms your potential to pay.  With the builder having bought the ICF blocks (on our site) he's left at the moment short until we pay the next stage.... and that certainly isn't fair on him.  What should have been a couple of days may turn into a couple of weeks.  And then of course there is the potential for the bank to refuse the application!! But I'm trying not to think of that.  So - all day is a scramble to get documentation together, rooting in various drawers etc.  Funny thing is both Lorraine and I bank day-day with the same bank and they have a more complete picture of our transactions than we do!!  Maybe they are looking to prove that we know what they already know so that they know that we know we can pay the mortgage.  Damn clever.

On the house front, we are delaying a day on starting the ICF walls because I don't know what size door to use internally!  All was fine until I visited a friends house and after a few minutes in there (and acting suspiciously around the door) I realised the door is subtly bigger than standard. It's not a massive thing, but I liked the effect.  It'll also be handy getting things in and out, such as myself when drunk!!  So, while I wait for a poor chap to measure up his doors at home we wait before starting as we need to cut the door openings into the walls as we build up the ICF.  At this stage though more delays are better until we have money to pay for the next bit.

Stress!

Choosing our Architect

(Spoiler : To see what we're building a summary of the drawings can be seen here)

One of the first things we had to do, and as a result its intimidating, is finding an architect.  As I know nothing about building I was concerned about being able to pick the 'right' architect, someone who could deliver a house that was different enough yet within a relatively tight budget.  We hoped for something less than traditional and would stand out a bit.

The first architect we talked to was a recommendation from a friend, who incidentally has a fantastic house.  We got an initial draft done of what he was thinking having looked at the site, and we were excited.  But we of course wanted a couple of opinions so solicited a few more.

The second we talked to also designed a house we knew of, but on seeing the location of the site didn't think that we'd get a house of the scale we wanted through planning, and strongly implied that he didn't want to make any waves at the planning office.  In my opinion, that's exactly what we're paying for (note: we're paying, not the planners!) an architect who will make the most of the regulations and policies set by the planners - push the envelope if you will.  We wanted a fighter.

The final architect we wanted to talk to first sent us off to look at a couple of houses in the area he'd designed before he'd talk to us.  If we were still interested then we were to ring him.. Homework.  We duly went and acted suspiciously outside a number of residences, concocting unbelievable cover stories in the event we were rumbled, when in fact the truth would have probably got us an invite inside and a chocolate biscuit if lucky.  On driving around remote country lanes we thought it may be difficult to see which house may be his.  However, every time the house immediately sprang out at us as remarkable in its situation.  They had a different look and feel and really looked like a custom house, not one pulled off a book of house plans.

So we went further, happy with our homework done we went for an interview... and it was both ways.  This guy didn't want to know if we wanted a straight-forward house, he wants to design a house, not throw it up.  Having blagged our way through that and accepted ;P we left with more homework - a wish list of what we wanted.  Open question and deliberately so.  At the end of this meeting, we knew we'd found the guy.  He let his portfolio speak for itself and was only interested in delivering something out of the mundane.  Looking back at no point have we regretted our choice as we're very happy with the outcome, as well as his management of the planning process.

The planning process isn't a one-way street.  There can (and should be) initial meetings with planners to set the tone of what is being suggested and how that fits in with the policies for the area.  The earlier that happens, the quicker the boundaries can be set and we can concentrate on designing with what will be allowed, rather than wishful thinking.  The initial meeting went very well, with positive noises from the planner.  Throughout the design process any significant additions or changes to the house was ran past them, usually as part of other interaction, and if we overstepped we removed and looked at it again.  This is also the benefit of having a local architect on the job (either as the principal or in an advisory role) as they will be very familiar with the local restrictions and personalities involved.

With anxiety we submitted our application for planning, our house is in an 'Area of Special Interest' and with the commanding view it also suffers from the opposite - it can be seen from everywhere.  While we had been in regular contact with the planners, the matter of the triangular windows at the front were a grey area up for debate.  We had compromised in removing the 1 1/2 story high front window, but it was far from certain.

Thankfully after the initial period had passed we were granted permission in one pass, with conditions but nothing that was too onerous.  The first hurdle was vaulted with no faults conceded! A night of (mild) celebration followed, and after that the sleeves were firmly rolled up to get to grips with what the task to hand was.  From there, it took another 6 months to arrange finance, agree a contractor for the structure, and line up the major trades to follow!

Scorchio, bbrrrrrrr

The heating system has been a constant headache since day one of the project.  As a technical piece it's also held the most fascination for me after the structure itself, with a background in Physics all the theory and design appeals to my illusion that I still remember what all the mumbo-jumbo was about.  However despite being decided, its not entirely risk free the way we've gone.


The system we're installing is attempting to be cost neutral over the medium term, return over maybe 20 years at current prices, and if Carbon Tax and oil goes as expected then return shorter than that.  It should also reduce the mess and hassle of oil, namely a dripping tank and calling for for refills.


We're fitting a flat-panel solar collector and an air-source heat pump (A2W).  The solar collector is as you'd imagine - a panel set on the roof that heats a liquid (not water) that circulates through the panels into a central tank.  The A2W pump looks like an air-conditioner, sucking in air one side and drawing out latent energy, blowing cooler air out the other.  It works just like Geo-thermal but without the ground pipes which are unsuitable for our site (horizontal) or too expensive (vertical).  This too feeds into a central tank - 600L in size.


This central tank or buffer store is kept at a temperature of about 40-55 degrees by a combination of these 2 systems, with an immersion coil as a booster in the event of these failing.  From this tank, domestic hot water is acquired by drawing cold water in one end, through a large coil and emerging hot at the other end.  The water in the tank isn't directly used, the energy is transferred.  Similarly, the underfloor heating draws water from this tank and is pulled on demand into each heating zone.  A thermostat in each zone monitors the temperature and when it falls below the requires a little motor in the UFH manifold opens and lets more hot water in.


Finally, we're adding MHRV.  This is mechanical Heat-recovery Ventilation and makes a huge difference to the efficiency of the house.  Air is drawn from rooms that tend to be damper (bathrooms/kitchen), up through an air pump and out.  Air is drawn in by the same pump and a honeycomb in the middle of the pump allows the the two air flows to be close enough to transfer heat without the gases mixing.  So you get warm fresh air pumped into rooms such as bedrooms and living rooms.  The motor only uses the energy of a light bulb.


The risk we're taking?  Well - the size of our build suggests a bigger heat pump than we're installing... but I'm heard a lot of anecdotal evidence to suggest the performance of an ICF house is better than an 'average' house.  So I'm under-spec'ing the heat pump now and will monitor it's performance over then next year or two, and if we need to bolt on more than we can look at the options then.  It's better than a bigger spend now at a cost of higher heating rates, but even with that it'll still be less than using Oil for a year.  


So - now thats decided, I can stop talking about my pet topic and concentrate on the more mundane items!

Floor plans

When we completed the excavation, we managed to mark out the various areas and room of the house for the outline, it really gave us a sense of how it will be.  With the levels created, we could also stand in the various 'rooms' and see what our view would be like!  We're really lucky in the site we've been given as the view is phenomenal with a panoramic view over Carlow town/county and the full range of the Wicklow Mountains in the distance.  Here is a composite of the floor-plan for each level.

 

The view is to the east and south, allowing us to maximize it with glazing that also helps us heat the house with solar gain.  But ignoring the benefit of it, we're really looking forward to being able to appreciate it daily from the various rooms.  One of the more interesting ones that we hoped for in planning is in the dining room on the middle of the plans, the curved wall will be entirely glazed.  Directly out that window (and 250m below) is Carlow town, and I think it will look great in there at night time with the sea of lights in that direction.

Naturally there are compromises in the plans, some people prefer separate rooms, others open living space etc.  This is a nice balance for us I think.  Can't wait for the walls to go up so we can really start to see it come together, hopefully completed over the next 2 months!

ICF - Insulated Concrete Forms

In Ireland, traditional build for years has been a 2 leaf cavity wall made from concrete blocks.  This consists of two walls of block separated from each other by a gap of at least 1 1/2".  The reason for the cavity is that masonary is pourous. and water will seep into it, through the outer leaf and into the cavity.  This is particularly true in wetter climates, and anyone who has spent a summer in Ireland can attest to that.  Popularity for this type of construction took off in the 1920's.  If you looked around Ireland's many building sites during the boom then you'd have seen a large number of cavity walls being constructed.

Above is a handy photo of such a wall from the internet.  More recently, these cavities have been packed with various insulation mechanisms, such as above, or blown-bead resin insulation.  While this has dramatically increased the insulation values of these walls, there are other problems.

ICF or insulated concrete forms is a different construction mechanism.  It is popular in other countries already, such as the US and Canda both whom have harsher climates (in su mmer and winter) than Ireland.  ICF houses are constructed from layering these forms on top of each other (like lego), and is a quicker and stronger mechanism than block.  Below is the anatomy of an ICF wall:

The ICF form is the polystyrene (like a coffee cup) on each side of the wall.  These are held together with a plastic tie that is hinged to allow it to flatten for packing.  The top and bottom of the form sides are crenellated and slot into each other.  They weigh virtually nothing (compared to the same volume of masonary block).  There is no glue or mortar to go between them, the polystyrene snuggles into the dips in the block below it.  In the plastic tie there are slots to lay steel rebar both horizontally and vertically to provide extra strength to the wall and help stop cracking.  Here is a rebar'ed setup

These are stacked up to a storey high, the openings for Windows and doors are cut out (its polystyrene so a knife/saw can do that) and shuttered with either timber or polystyrene to prevent the concrete escaping.  Then a concrete pump is used to pour concrete in the top opening, and left to cure.

All sounds good - you now have a highly insulated (say 0.2 w/m2K) wall thats very strong.  That alone might tempt you over the cavity wall, but - as they say on the shopping channel, that's not all.  You also get the following

1. Airtightness - no gaps in the wall/floor junction or between bricks
2. Strength - as described
3. Easier construction - less room for poor quality work.
4. Faster construction - foundation to roof plate for our build in perhaps 6-8 weeks
5. Great sound insulation

There is probably more, but this is what sold me.  It also allows us to use pre-cast hollow-core concrete floors for the 1st floor, so no creaky floorboards or TV noise from downstairs.

I will say that a well-constructed block house will provide every bit as good a structure as ICF - however you really need to be sure that the builder is skilled enough and pays enough attention to detail to compete.  This is the real difficulty.

Also a benifit of the ICF method is that the house has a much higher mass and density.  This leads to a thermal mass, i.e. a mass that will retain heat or stay cooler for longer and regulate the internal temperture more.  Think of it as a shock-absorber for temperture, smoothing out the bumps of hot and cold changes.  Coupled with under-floor heating these are both working in a similar way and complement each other well.

Finally about air-tightness.  Every house needs to breathe.  Traditional construction in Ireland has been to put holes in the walls and place a grate over them to provide this... so there are literallly big holes in the wall.  Imagine that when trying to stay warm in winter with a gale howling outside!  ICF houses are no different, but rather than punch big holes all over the house we'll install Mechanical Heat Recovery Ventilation.  Probably another post on that, but if you are going ICF it's worth the extra investment to install MHRV.

Estimates

Trying to estimate the cost of a build is very difficult - even when you have direct quotes for items these can and will expand as unforeseen changes or issues arise.  Here is a quick breakdown of the current estimate as a percentage.

You can see there is room for this to change, and as the structure is the most planned item at the moment it is probably a little disproportional to the entire build.

Context

Big gap between the first and subsequent posts, and realising there is no context for what we're building I'll go into some detail.

The site is approx 1 Acre, heavily sloped. We have a perfect entrance already for us. The house is going to be almost exactly in the middle of the rectangular site (long edge running downhill). House will end up being about 509m2 or approx. 5500 sqft so a big house to get my teeth into! It's on family land and we're planning to live out the rest of our hopefully long lives there, if we do end up leaving for a time it won't be sold.

So the challenge is to build this in an economic time where lending is at rock bottom, the threat of job redundancies faces everyone and basically money is tight. The plans were made in slightly better times shall we say, but if we are careful and tighten down on everything we should be able to complete. The result is that we have to go the direct labour route, hiring all the contractors ourselves rather than a turnkey builder delivery. Naturally, there are gaps between what contractors do which need to be filled by yours truly, hopefully with a little help from friends, family and neighbors!

Planning went well - kudos to our architect whom I'd highly recommend for anyone. We got through with reasonable conditions and no objections. We both really love the house on paper, and are excited about starting to see it develop.

So a number of construction challenges to be overcome, a non-traditional construction methodology (ICF), and my own desire to ensure that we do it the right way - i.e. not follow the herd but understand what we're putting into the house and why. I'd like to say best practice but in reality that means different things depending on what outcome best means to you.

Time lines are estimated about a year but we have no strict deadline for a finish time. Sooner is better but only from our own desires to move into it and settle into the community. The downside of it is that its easy to let things slide a bit and maybe I'll revisit a plan to get a closer end-date, the real issue with doing that is that I'm not sure how long each part takes so it would be a heavy estimate. The first milestone is really to get weather-tight by Autumn so that internal trades can continue in bad and colder weather. The only outstanding item with that is the windows - primarily the colour but we don't yet need to order that.

Renewables

The biggest outstanding question in my head, and probably always has been since we decided on the structure type, is the heating. I'm convinced on the comfort of Underfloor, and happy with the idea of MHRV. The problems start once we get into sourcing the energy.

Currently, you can probably supply fit & commission a condensing oil burner & tank for about €3,000. This then has a high constant outlay over the lifetime of the burner, but low capital cost.

The other option is a heat-pump. However - the area to be heated in our house is significant, and so a single pump (on the premise of single-phase electricity supply) would not cut it - certainly for a traditional build. So - I can either install 2 pumps (say 14kW + 11kW), install Oil and a single pump 16kW, or and what I had been thinking, is to chance a single 16kW with an immersion coil and bet on the insulation finish on the house to be enough to reduce the load.

I've been in an ICF house that was about 20% smaller than mine in area, but heated with a single 11kW A2W pump the inhabitants were very happy, but ran it at 18C and the property had a much smaller glazing area. Thats what pushed me to a single 16kW pump and hoping for the best.

A potential supplier modeled the heating requirement (subject to massive assumptions and average weather) and it looks like once we go below 0C we need backup from the immersion coil.

On top of all of this is solar. 'Free' energy for nearly 3 seasons sounds like a great buy, but with the Heat Pumps able to operate at night & heat a buffer during these times it's saving the night-rate electricity - currently about 8c/h.

The only thing thats not making me pull away from all and any renewables is that we will be living there long enough for the bigger ROI plays to pay out. Anything around a 20 yr horizon isn't too daunting.. more than that and I have to think hard. You can guess where I think our ROI will be!

To blog?

Ok - so my initial feeling on blogging was not to, and so until now I maintained that. However - a realisation that blogging isn't for others, but for myself has made me re-evaluate that decision, and now that finally we have started the build it's the appropriate time to see if I can maintain this. Since I've never kept any type of Diary, this may be a discipline too far. But since I advised others to blog some of their adventures and ignore those who dislike the idea, I suppose I should follow my advice and hopefully have this to look back on once the pain is forgotten.

To recap on the last year we have had to:

• Obtain Planning Permission (obtained June 09)
• Apply for and be accepted in principle for a mortgage in this climate.
• Select a contractor for the structure (decided Dec 09)
• Obtain right-of-way to access the site (obtained Jan 10)
• Decide on contractors for other major items in the house (ongoing)
• Get an excavator and operator to dig (Mar 09)

As of Mar 19th we have offically started, with the excavator breaking ground. There is a massive amount of earth to be removed with the split-level over basement design requiring digging into the hillside. As of today we have excavated as per the picture.

Nothing is easy - already only 1 1/2 weeks into the build the changes and problems start.. first off the heating system may get a good bit more expensive due to the floor area of the build... that or we change tack and go with dirty old oil. Second and more immediate is while digging out the lower section for the basement we've hit 2 water springs that subsequently flooded down the road - the picture below is after we cleaned up a lot of washed out silt. The result of that is we may have to move the house back 4 feet or so and drain off the springs.

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First off!

Started the proceess by talking to those with the money and therefore the power. So far, it looks positive from the banks about getting the sort of money we'd like, so it's more a question on repayments. Of course, we have to decide what to do with our existing house. In this climate selling is a poor option, but renting is hassle, and personally I think likely to dry up as houses move into a more affordable level. But we don't need to fully decide that until we're ready to move out of it, so who knows then.

Also - realised that the government grants for sustainable initatives are gone for new construction. Basically, as some element of renewable energy is required in every house when the next set of building regulations come in, there is no need to incentivise people to get it! It's reasonable of course, just removes some of the safety net around costs.