Installation of Heat Recovery Ducting & Insulation in attic

This week Peter and John were back in the attic. The ducting for the Temovex HRV is being installed. Per the Scandinavian Homes instruction manual all ducting must be wrapped in insulation even though there will be 600mm-700mm of blow cellulose installation. This is an important detail to ensure the performance of the heat recovery and ensure heat-loss through the ducting is minimized. Lars explained that the top of a warm duct can be as close the cold air in the attic as 165mm. The cellulose insulation is low density near the top and
convection movements of air can take place within the cellulose insulation unless the duct is wrapped with insulation. Scandinavian Homes supplies a special duct insulation for all bungalows. In houses with converted attic-space this never becomes a problem because the ducts are located inside of the heated envelope of the house. In other words, heat losses from ducts take place within the joists of the upstairs floor and in the void-space on both side of the upstairs.

In total 320 x 13kg Warmcel bales will be blown in. 320 x 13kg = 4160kg = 4 metric tonnes.Flaherty and Goaley now have their own equipment so can supply and install.

Air Permeability Test Results

We are hoping to get our house certified by the Passive House Institute in Germany.

The Passive House register of can be searched at
http://www.passivhausprojekte.de/projekte.php

Building envelope air-tightness is a key requirement for certification by the Passive House Institute. The house must achieve Air leakage through unsealed joints of less than 0.6 times the house volume per hour.
For further details on the basic features that distinguish a passive house please review
http://www.passivehouse.com/English/PassiveH.HTM

On the 12th November 2010 Ronan Rodgers from Energy Matters arrive on site to perform the Air Permeability and Thermography testing. A door blower was installed as shown below

We achieve a figure of 0.27 air changes per hour. Easily exceeding the Passive House Institute requirement of 0.6. Ronan commented "The result is a truly excellent!   It far exceeds any result I have ever tested"

Getting such an excellent result was down to the several factors including the house type. Building a rectangular single storey makes it more straightforward to envelope the interior with the vapour barrier. But without doubt the key success factor was having skilled tradesmen. Next to Lars himself no one is more familiar with Scandinavian Homes that Flaherty & Goaley. Peter & John have worked with Scandinavian Homes for almost 20 years and have erected practically all of the house. Both appreciate the attention to detail that is required at key stages of construction. Any shortcuts taken will surface at test time. Some examples include:
1. Fitting ceiling battens and plasterboard
2. Using quality (age-proof) tapes and adhesives
3. Working closely with plumbers and electrician to ensure those trades work carefully to ensure they do no compromise the air-tightness



Heating & Heat Recovery Ventilation

Our house will be heated using the following means
1. Electric Underfloor Heating: 1 x 2295W 130m circuit for living area and bedroom
2. Electric Underfloor Heating: 4 x 270W 15m circuit to bathrooms, utility & home office
Controls: 5 x Devireg 535 Timer & Thermostat

The 130m circuit is installed primarily to help the raft dry out and boost the heat in the house once we move in.

Heat Recovery Ventilation is via a REC Temovex RT 400S-EC supplied by Scandinavian Homes. All ducting to be insulated and sitting inside 700mm blown cellulose insulation. This unit included a 900W after heater with bypass to ensure not Heat Recovery during warm weather.

Heating will in run using Night saver electricity on a Dual Tariff Meter.  Total 4275W which is equivalent to two typical oil filled radiators.

Lars Pettersson has calculated that we can expect the peak heat demand of <5W/m2. i.e. With reference to the Scandinavian Homes Show House he expect real usage 3.2W/m2 so for 196sqm x 3.2 = 627W. Which would suggest that only the 900W heater in the HRV is required to heat the house to 21 degrees on the coldest day of the year. Bearing in mind a typical 2 slice toaster uses approx 800W-1000W

U-values for Scandinavian Homes Super Passive Specification

Walls (335mm insulation) U-value : 0.01   (Current Part-L maximum U-Value : 0.27)
Roof (700mm insulation) U-value : 0.047 (Current Part-L maximum U-Value : 0.16)
Floor (280mm insulation) U-value : 0.109 (Current Part-L maximum U-Value : 0.25)
Windows (Triple Glazed) U-Value: 0.92  (Current Part-L maximum U-Value : 2.0)

Technical Information

House Type - Hibernia.

Section - Super Passive Single Story.
http://www.scanhome.ie/archive/drawings/S09%20Super%20Passive%20-%20single%20storey.pdf


145mm + 120mm + 70mm Insulation in all external walls.

Foundation with insulated base unit.
http://www.scanhome.ie/archive/drawings/M01%20Foundation%20detail.pdf


80mm + 200mm insulation + Insulated shuttering.

Build Costs

Groundwork's including site preparation, supply & install of well with pump, rainwater harvesting & sewage treatment = €40,000. If you have a serviced site then you will not incur these costs.

Construction costs on prepared site
  • Insulated Raft to Scandinavian Homes specification.
  • House supply & materials to fit-out includes UFH, Heat Recovery Ventilation,
  • House Shell erection
  • Fit-out includes external render, internal partitions, taping & jointing, air-tightness detail, carpentry, install of HRV, roofing, guttering etc.
  • Electrical
  • Plumbing
Total :- €248,000

With gross floor area - 206sqm = €1200 per Sq.m or €110 per sq.ft.

Note: This figure also excludes solar, tiling, painting, kitchen, furniture, legal fees, architect, BER, air-tightness testing, driveway, landscaping.

For further details please review the Scandinavian Homes Pricing & Buying Guide

Conclusion

We haven’t moved into our new house yet but already we are certain that we made the right decision to build a Scandinavian Home.  The quality of materials used and the skilled workmanship are what set this house apart. Most importantly we are on track to complete the house on time and in budget.  We are convinced we will have one of the most energy efficient houses in Ireland and one which is exceptionally comfortable to live in.
Our thanks to everyone involved in the design, build and supply as listed below
Company
Contact
Role
+0049 8142 3057533 Germany
091-447121 Ireland
Architect and Certified European Passive House Designer.
091-586176
Planning Application & Signoff
086-8143040
Grounds work & Raft
091-555808
House supply & Materials
087-8301250
House erection and fit-out
086-8290872
Plumbing
087-2592008
Electrical
091-380631
Air Permeability Testing
044-9374108
Septec 2000 Sewage Treatment
044-9374108
Rainman Rain Water Harvesting

Building our Scandinavian Home.

Groundwork’s – 3 weeks

James Kearney arrived on site on Monday 30th August along with his trusty helper  Pavel and his nephew Brendan.  James took everything in his stride and there was no problem that could not be overcome. He drove from Headford every day and I was amazed that in the 4 weeks he never once arrived on-site having forgotten something he needed for the day ahead. James oversaw the installation of our Sewage Treatment (Septec 2000) and Rainwater Harvesting System (Rainman) supplied by Shay Murtagh Ltd, Raharney, Mullingar, Co. Westmeath. Shay Muragh’s crew co-ordinated delivery and installation with James to ensure the preparation work was complete. Shay Murtagh’s technical team will be back onsite to commission both the Rainman and the Septec 2000 Systems once the house has mains supply of electricity.
James ensured that all measures were taken to ensure that all pipe/ducts etc were sealed appropriately for air-tightness. He was always available to discuss any concerns and offer advice.  After 3 weeks grounds work were complete and on Monday 20th September James started constructing the raft on behalf of Scandinavian Homes.

Raft construction – 1 Week

The switch from digger and heavy equipment to the precision work involved in the raft was very noticeable.  To see the raft start and complete in one week was extraordinary. The only problem encountered was a breakdown of one of the cement lorries on the Friday. This resulted in a setback of 5-6 hours and meant James had to work right through the night to complete the power-floating.  Again there were no complaints, James  and Brendan checked in to a local B&B and completed the power-floating at 5am.  
House Erection – 2 Weeks
On Tuesday the 28th August 2010 at 6:30am the first lorry and the crane were on-site. Peter & John were also ready to start work. By lunch time all the external walls were in place. By 4pm the roof trusses were in-place. The progress was astonishing. At 6pm Peter handed me one of the keys to my house!!  At 4pm on Thursday the 30th August the house was weather tight.  Shell erection was complete by the end of the next week. I review the checklist with John and at it was time to complete my payments to Scandinavian Homes


Fit-Out – 8 weeks and continuing

On Monday 11th October Peter and John started work on the Fit-out.  Peter, John and crew arrive on-site at 8am every morning. We cannot speak highly enough of these men. The pride they take in their work is second to none. The attention to detail is phenomenal. I told them that I was hoping to get our house certified by the Passive House Institute. A key requirement is achieving an air-tightness value of <0.6 ACH. John and Peter put in an extraordinary effort to ensure we met this. Ronan Rodgers of Energy Matters conducting the air permeability test on the 12th of November and we achieved a rating of 0.27 ACH far less that the Passive House requirement. This was down to the hard work, expertise and attention to detail by Peter and John. The quote from Ronan Rodgers said it all “Please see the attached Air Permeability and Thermography test report for your dwelling.  The result is a truly excellent! It far exceeds any result I have ever tested.
Today, 7th December our tiler started work. We have painted the first coat to three bedrooms. Extraordinary progress considering we have been held up a bit by the bad weather and only 14 weeks earlier we had a green field.

Costing & Purchasing our Scandinavian Home.

Once we had a design we liked it was a matter of sending the drawings to Lars who was able to give a costing (usually within 24 hours). For a conventional house it was take 2-3 weeks for a builder to provide a quote.  Lars confirmed that he had several builders who could complete the fit-out of a Scandinavian Home to a turn-key finish.

We spoke with Peter Flaherty of Flaherty & Goaley Contracts (who erect the houses for Scandinavian Homes).  Peter took us to see two houses under construction and we decided that we wanted them to complete the fit-out. Once again it was a simple matter of sending the drawing to Peter & John who were able to quickly provide a fit-out cost.

We also met with James Kearney of Rostaff Developments. James is employed by Scandinavian Homes to construct all foundations for Scandinavian homes. James is also a builder with many years  experience and we asked him to visit our site and quote for groundwork's.

At this point we were able to get a very accurate build costs.  This was vital when dealing with the bank.

We engaged Niall Kearns or Niall J. Kearns & Co. Architects to complete and submit our new planning application (under a change of house plans). Our application was submitted on 14th May 2010 and on the 6th July 2010 we were granted permission. We were keen to starting construction as soon as possible so were delighted that Niall managed to get permission on the first attempt. 

On the 7th July we signed the contract with Lars to build our house.
 

Designing our Scandinavian Home.

Lars arranged for us to meet with Peter Lohr, the Scandinavian Homes architect. Prior to doing so we decided to abandon the house we had planning permission for and start from scratch (for the 3rd time!!).  We also reviewed our requirements and put together a simple spreadsheet listing what rooms we needed in the house and the minimum size we would need for each room. After doing so we realised that we needed a house of no more than 190sqm of internal floor area. The house we had planning permission for was 249sqm. This also made it clear that we would be opting for a Hibernia or Nordica. We also decided to opt for the Super Passive Specification but in a single storey form. Lars confirmed that the Hibernia 201 was the most cost effective house type to build and well suited to the Super Passive Spec.

It was really helpful to have access to the huge database of designs that Scandinavian Homes have built up over the years. Peter Lohr listen carefully to our requirements and it was quite incredible how quickly he was able to come back to us with completed drawings.  After many iterations we arrived at a design that we felt provided what we wanted. Its worth pointing out that the fee charged by Peter was per hour. We had a lot of homework done ourselves so the architect fees were very reasonable and ran to no more that several hundred euros.


At this point we engaged Niall Kearns of Niall J. Kearns & Co. Architects to submitting a new planning application for a change of house type. For a very reasonable flat fee Niall took care of  planning application and the required inspections & sign-offs for the bank.We received planning permission on the first attempt which was an excellent result as we were keen to start building as soon as possible.

First visit to Scandinavian Homes


After 10 minutes in the Passive House at Tooreeny, Moycullen we felt this was the type of house we wanted to live in. The house is right beside the busy Galway/Moycullen road and once the door was closed not a sound could be heard. There was a lovely internal atmosphere that we really hadn’t experienced in any other house. Lars put on a video for us to watch. We learned that when you buy a house from Scandinavian Homes you must also buy the raft. The raft is crucial to the overall success of the house and it is vital that is constructed to the exact specifications required by Scandinavian Homes.  After watching the video, taking the tour and speaking with Lars we knew we wanted Scandinavian Homes to build our house.

Some background and earlier planning applications

Between 2007 and 2009 we obtained planning permission for two house designs. The first was for a large H-shaped single storey.  We took the plans to Peter Keavney at the Galway Energy Agency for some independent advice regarding building to a “low energy” spec.  Peter felt the design was very poor and estimated approx €3000 - €4000 per year to heat even with a high spec in terms of insulation etc.  We decided to go back to the drawing board and submitted a second planning application for a more conventional two storey house.  Once again we spoke with Peter Keavney who confirmed this was a much better design but he suggested we take a look at what Lars Pettersson was doing with Scandinavian Homes.


At this point we had sold our house in Galway and were keen to proceed. Planning Permission was granded and we decided to get some quotes from some recommended builders.  We found this quite challenging as each builder had a different way of quoting for construction. Some provided very detailed quotes others provide a basic costings. Our bank had told us to get the mortgage amount right and ensure we would not be back looking for more funds – it was therefore vital we got the costing right. The property boom had ended and we were being told it was a great time to build and that we should build a new house very cheaply.  It was quite a shock when we started to get quotes much higher than anticipated.  It became apparent that a lot of the cost was in the materials. Labour costs might have reduced but installing high levels of insulation, triple glazing, heat recovery, geothermal/wood pellet etc were all adding to the costs.  At this point we made the decision to visit Scandinavian Homes.

We had also spoken with timber frame manufacturers but felt that they were really only interested (perhaps to be expected) in erecting their structure on a completed raft and then walking away.