SIPs Installation

SIPs Installation

It has been a long time since the initial blog on the SIPs house in Wanaka, so I thought I would continue the story and show the ease of the installation of the SIPs panels.

01 CNA SIPS individual panels

This first image shows the smaller individual SIPs panels that were small enough to bring to site by trailer. With fixings through the OSB sheathing into both sides of the bottom plate, these panels were very solid in themselves and didn’t really need the bracing.

02 CNA SIPS arriving on site

All the large preassembled SIPs wall panels are delivered to site on a single load of a Hiab.

03 CNA Unloading SIPS with Hiab

The panels are drilled to provide two balanced lifting points which makes positioning of panels easy for installation.

04 CNA Foam to bottom plate

Before each panel is lowered into position, expanding foam is placed along the bottom plate to fill any voids between the bottom plate and the bottom of the rigid urethane insulation core of the SIPs panels.

CNA air seal to SIPS panel joint

Along with the expanding foam to the bottom plate, a bead of sealant is placed against adding panels to form an air seal between the panels.  We did not rely on this air seal completely as every panel joint was sealed with Proclima Tescon Extoseal tape prior to adding any internal bates and linings.

06 CNA check before initial tacking

Each panel was carefully aligned to be true and plumb prior to temporary fixing.  Final fixing of panels to bottom plate and adding panels occurs when all panels are in place.

08 CNA SIPS panel alignment

The hiab operator was quite familiar with the installation process. While the builders were checking for true and plumb panel alignment and temporarily fixing the panels, the hiab operator had another panel lined up and ready to be lowered into place.

09 CNA SIPS panel in place

The accuracy of the panels was outstanding, this panel simply slid into place and did not require any adjustment. Panels with raking heads also fitted together with a high level of accuracy.

10 CNA SIPS panel splice

Where walls were too large to be transported as one, individual sections could be spliced together on site.  The Kingspan Tek system has a smaller piece or ‘splice’ of Sips panel that fits within the depth of the insulation core which is then fixed to the two adjoining Sips panels. This provides a very strong and easy connection but more importantly it provides a complete thermal barrier of urethane with no thermal bridging between inside and out.

11 CNA SIPS panels installed

The house comes together very quickly and gives an immediate idea of how the windows and doors frame the various views. Structure, insulation and sheathing all in one.

13 CNA SIPS house after an afternoons installation

The installation of these panels took a single afternoon.  The following day all panels were checked and adjusted where needed prior to final fixing.

15 CNA SIPS Double top plate

Following this timber framed elements were added. This included framing for items such as bay windows, roof beams, internal walls and the addition of a continuous top plate.

14 CNA SIPS add internal framing

With the addition of framing, we had to start thinking about achieving a complete air tight environment. Because of the low pitch of the roof we opted for a traditional timber framed structure.  Any external timber framing achieved air tightness by the addition of an Proclima ‘Intello’ humidity variable moisture control layer.  Here you can see a section of Proclima Intel Plus connection strip which will run over the top of all internal timber walls.

19 CNA SIPS Insulated lintel

 

The SIPs panels are easier to seal. The builders drill holes around all panel connections and inject expanding foam to fill any air gaps. Then these holes and holes for any lifting eyes are taped with Proclima Tescon tape as per the photo above.  All joints between panels (in line or at corners) are also tapped to ensure an airtight seal.  In the above photo you can see that the lintels were held back from the external face  so that when the top plate is installed the entire lintel can be covered with a layer of high grade insulation minimising thermal bridging across the face of the lintel.

17 CNA SIPS Box beam

With the addition of plywood box beams, lintels and verandah posts the bones of the house are complete.  The area of external timber framing is a storeroom that adjoins the triple carport. Electrical services are bought into the building at this point and with the reduced need for insulation to this room, timber framing became an option.

Situation Vacant: Experienced Architectural Technician

We are looking for an experienced Architectural Technician to join us in our Wanaka studio.

We are a small design based NZIA practice with passion and focus on site-specific, energy efficient, contemporary residential projects mainly in the Queenstown Lakes District and Central Otago, but also further afield in NZ.  We work with both NZ and overseas clients who want to achieve the ultimate kiwi lifestyle.  We take a client-centric approach with personalised service and open communication, all within a creative and collaborative environment.  Current projects include residential and commercial projects in Wanaka, Queenstown Central Otago and Wellington.  We love living amongst the lakes and mountains and are avid skiers and mountain bikers. Our studio has great views to the mountains and we are located within walking distance to the lake and the town centre.

Your role will be to produce clear thorough and concise contract & tender documentation.  You will liaise directly with clients, sub-consultants, councils, suppliers and contractors.

We will consider an outgoing person with the following skills & attributes;

  • Confident, well-organised, professional manner, with good communication skills.
  • Friendly, honest and with good interpersonal skills and with a good sense of humour.
  • Imaginative, enthusiastic and motivated, with a can do attitude.
  • The ability to problem solve and apply logical thinking.
  • A high level of interest and understanding of how materials and components are put together, melding beautiful design with ‘build-ability’.
  • Good knowledge of environmentally sensitive construction, sustainability and energy efficient design.
  • Comprehensive technical knowledge of building systems and construction techniques and methodologies.
  • Thorough understanding of the NZ Building Code, NZ standards and regulatory processes.
  • Excellent graphic presentation skills, both hand-drawn and computer generated.
  • A proficient operator of ArchiCad as both a BIM modeling tool and 3D presentation tool.
  • The ability to work collaboratively as a team player but also to work independently showing initiative and good time management to steer a project from concept stage through to physical delivery.

This is a full time salaried position so permanent NZ residency is essential. There is some scope for flexibility in working hours enabling you to be inspired, able to enjoy your work and achieve a good work / life balance.

You will work with assistance and support from both a registered architect and the practice director.  Ongoing professional development is encouraged and fostered.  We pay professional memberships and offer support with continuing professional development or assistance toward NZRAB registration.

Good remuneration appropriate to experience, skills and development.

Please email your CV and 4 or 5 examples of your work by 9th January 2017 to;

The Practice Manager
[email protected]

Thermally Broken Slab & SIPs Preparation

Thermally Broken Slab & SIPs Preparation

Although the building code only requires the finished floor to be 225mm above finished ground level we decided that this new house should be raised up from the ground 400mm for several reasons;

  • The first 200mm of air above the ground can be the coldest in winter,
  • As the last house in the subdivision we could pick ourselves up higher than the neighbours to get better solar gain and to offer better views out from the site while remaining on a single storey connected to the outdoors,
  • You can use as much garden mulch on garden beds as you like without the risk of rotting out the weatherboards,
  • Stepping up into the house stops dust and garden debris being blown into the house as found with many level threshold houses,
  • Low flood risk,
  • Easy to detail free draining decking around the house as a cheap method of achieving a level threshold and reducing water risk,
  • 400mm is an ideal height for siting on the edge of a deck.

This required the slab to be built up from the existing site with free draining backfill but also allowed the use of 100mm EPS polystyrene which the builders like as it is more rigid and easier to control than 50mm insulation. Usually I would use the more expensive XPS insulation (extruded) as it is closed cell and doesnt take up moisture but as we would be higher than the water table/ ground level I was happy to use the S grade EPS insulation (expanded foam) in conjunction with a good damp proof membrane.

Foundation formwork

We often see thermal diagrams showing the greatest amount of heat loss is out of the side of the slab & foundation, and having lived in a house nearby that has an uninsulated slab, I was very much aware of the need for not only good under-slab insulation but for a thermally broken slab edge. One end of that existing house sticks out of the ground about 300mm or more and the clearly noticeable conduction of the cold through the foundation edge and into the timber overlay flooring for a good couple of metres is a good demonstration of the heat loss at the perimeter of the house. Not only is the slab edge an area of heat loss, it is an area of condensation as the warm moist internal air meets the cold slab edge.  To prevent this thermal bridge and condensation it is important to thermally break the slab from the cold foundation wall which in my mind is better than insulating the foundation as the footing would typically be in contact with the cold ground.

Phenolic foam insulation as thermal break

The photo above shows the use of a high grade Kooltherm phenolic foam insulation to the slab edge. Reinforcing bars pass through this 50mm insulation into the slab and the cuts in the insulation are then filled with expanding foam to minimise any potential thermal bridging.

Underslab insulation

This photo shows that the foundation walls have been poured, the formwork removed, the damp proof membrane & underslab insulation have been laid with reinforcing steel placed ready to receive the concrete slab. The darker coloured high grade insulation can be seen to the inside of the foundation showing that the slab will be completed isolated from the foundation. You can also see a set-down in the slab insulation, where 50mm Phenolic foam has been used to create a slab thickening allowing for steel reinforcing to pass into the slab below a door opening.

The images above show the placement of the slab concrete prior to floating the slab smooth and level with a power float. The thermal break is still visible below the thin layer of concrete spill and this will be cleaned up as the foundation wall is checked for any high points. High points are ground down to ensure a completely level perimeter ready to receive the bottom plate.

Bottom Plate

Bottom plate planed flat

The above images show the placement of the first 140mm bottom plate and hold down straps. The hold down straps are located at the ends of panels and adjoining point loads from window lintels. As we are aiming to achieve a good level of airtightness there is a bead of sealant between the bottom plate and the slab/DPC. Each section of bottom plate is tooled flat and level to ensure that the entire house perimeter is level and that the SIPS panels will butt squarely together.

Double bottom plate

SIPS bottom plate

Thermal mass walls to corridor

The second bottom plate is laid over the level first bottom plate and again receives a bead of sealant to close any air gaps. This second plate is 110mm thick which matches the width of the urethane core of the SIPS panel. Each panel will arrive with a 50mm deep rebate of insulation between the OSB sheathing so that the panels simply place over this second plate and the SIPs panels are fixed continuously on either side into the bottom plate.

Kingspan Tek Panels in the Kia Kaha workshop

Scott inspects the Kingspan Tek panels in the Kia Kaha workshop during fabrication. The panels arrive with each edge rebated so that it can either be placed over the bottom plate or they can be spliced together with a thinner SIPs jointer panel which eliminates solid timber connections further reducing thermal bridging.

Complete SIPs wall

A completed wall panel showing SIPs splice connectors. Each splice provides two layers of 15mm OSB to each side of the panel that are fixed together at regular centres providing a rigid connection without any thermal bridging. You can also see a timber ‘post’ within the panel to the side of the window opening. This post transfers the point load created each side of the window opening as the roof loads are transferred through the window lintel down each side of the window opening.

SIPs panels

Complete SIPs wall panels stacked ready for delivery to site

Wanaka Energy Efficient SIPS House

Wanaka Energy Efficient SIPS House

We are well underway with the structure of a new energy efficient family home at 52 Dale Street in Alberttown. The house is for a typical Wanaka family of 4 with all the associated equipment that comes with a love of the outdoors whether this is at home, around Wanaka or further afield. The house plan accounts for changing needs of teenagers, allowing some independence but also keeping the family unit close knit and allowing to accomodate  family and friends.

The site is the last vacant site in the original stage of Riverside Park so the house had to take into account the position of the surrounding residences in order to create outdoor spaces, avoid overlooking, utilising the sun and making the most of selected view-shafts. Knowledge of how the clients live in their existing Alberttown residence has been utilised to create an outdoor courtyard area that captures the summer sun from mid-morning to late afternoon while sheltering from the typical North-West summer breeze. Alternative outdoor areas (or ‘rooms’) are created to the North and East, vege gardens to the West and the business end vehicle and services areas to the South.

Floor Plan of Proposed Residence

The clients currently live in a 1970’s crib (Holiday Home) that was renovated 6 years ago, receiving a full interior fitout with new internal finishes fixtures and joinery, and as much insulation as possible, so they are fully aware of the benefits of improved thermal performance. However there are limitations on how far you can thermally improve 40 year old construction, so the decision was made to start fresh and employ the best and most current thinking in thermal efficiency. The principles of Passivhaus construction have been employed but only to the extent that readily available materials and construction techniques have been utilised. The construction contract for the house went out to tender to several home group companies and to builders that where familiar and passionate about energy efficiency and eco friendly construction.

The Tender was won by a local building company Kia Kaha run by Scott Pickett who priced competitively and also provided some good alternative options on construction and materials. The house was detailed with 150x50 timber framing that was sheathed with plywood RAB for airthightness and bracing, and with a horizontal 45x45 structural batten to support the cladding and to eliminate the need for noggins (dwangs) this reducing the amount of thermal bridging through the structure. Internally the 150x50 framing was wrapped in Intello which is an airtight vapour control  membrane, and also with another 45 x 45 horizontal batten allowing for a services cavity to minimise penetrations through the vapour control membrane and allow an uninterrupted layer of insulation. A further layer of 50mm insulation was run between these internal battens to reduce thermal bridging further. Scott from Kia Kaha Developments proposed an alternative wall construction using Structural Insulated Panels (SIPS) that would not only improve the insulation value of the wall by reducing thermal bridging, but saved $15,000 on the cost of construction. Scott has built about seven SIPs houses in the South Island, including New Zealand’s first SIPs house in Alberttown (less than 100m from Dale Street) so is not only a leader in this technology but has good experience in its construction. The SIPs panels used are Kingspan TEK panels that are imported from the UK. There are some NZ based alternatives arriving on the market but currently the Kingspan panels are superior and cheaper, with a 110mm Urethane core sheathed both sides with 15mm Type3 OSB (Oriented Strand Board). This marine grade OSB is absolutely formaldehyde free, glued by PMDI resin and provides all the required bracing and forms an airtight barrier.

I will enter further detailed posts on the use of the SIPs panels on this project aswell as other elements of the design that are being utilised to create a comfortable energy efficient home that is far superior to current building practices.

Northlake Wanaka : Plan Change 45

Queenstown Lakes District Council called for public submissions on the Northlake Plan Change by John Edmonds and Associates for the land owner Michaela Ward Meehan. Following is my rushed submission to QLDC;

Thank you for the opportunity to submit on the proposed Plan Change, however I have to express my disappointment at the level of notification of this Plan Change. Plan Change 45 is one of the largest proposals to effect Wanaka both historically and likely into the future.  It may have a larger impact upon Wanaka than previous Plan Changes such as Peninsula Bay and Three Parks yet there is a distinct lack of consultation from QLDC in comparison to those Plan Changes and other capital works such as the Ardmore Street roundabout and car-parking. I became aware of the Plan Change Notification through an article written by the Wanaka Sun newspaper which we received on 25th of August, this despite being an avid reader of local papers with a subscription to the ODT and working actively within the design and building industry.

Wanaka ratepayers are highly interested in the direction of this town so I think QLDC will need to consider the effectiveness and validity of this process if you do not receive a high number of submissions (I suggest you compare the number of submissions against the numbers received for smaller Wanaka issues such as parking on Pembroke Park, Cinema Paradiso and the changes to the Wanaka Library Staff levels).

Despite the lack of time and clear information from QLDC, I do support the idea of the Plan Change and do commend the various land owners for combining together to work towards a cohesive development.

Density

This area of land is within the urban growth boundaries as defined by the Wanaka Structure Plan so it is expected to be developed at some point. However it is the proposed densities that need further consideration.

Zoning D1-D3

I do support the idea of mixed densities and I have no issues with the sleeve of higher density zoning D1-D3 shown to the Outlet Road and the future ‘central road’. However High Density zoning needs to be comprehensively planned and cannot be left to market forces alone, so this proposed zone needs particular research, guidelines and level of control. Wanaka already has some examples of higher density  (although not as high as the density proposed) one has a reasonable level of success, another other not so. The Kirimoko block has been carefully designed and has achieved a reasonable level of amenity, whereas the higher density areas of Riverside park in Alberttown have had no design input or control and is a less than satisfactory level of development.  Therefore the applicant needs to provide additional information and guidelines before a high level of density is approved.

Zoning B1-B5

This zoning makes up the vast majority of the Plan Change however it contravenes the intentions of the Wanaka Structure Plan with its proposed density of 10 dwellings/ha. The Wanaka Structure Plan outlines an appropriate density of 5 dwellings/ha.

The extent of this higher density is inappropriate as it provides blanket suburbia with little visual or physical amenity. This density is higher than the Lake Hayes Estate (8.4 dwellings/ha ‘QLDC District Capacity, 2008) over an area greater than Lake Hayes Estate. It is frequently commented that Lake Hayes Estate is a poor quality suburban environment even with the surrounding natural landscape features. This level of density does not allow for landscaping to mitigate the built environment.

Consideration needs to be given to Wanaka’s growth projections as the most recent study was completed and based upon growth numbers during a boom period prior to the recession (Wanaka Land Demands Study: 2007). The overall density of the Plan Change allows for higher densities than allowed in the Wanaka Structure Plan which was based upon high growth models with a fair amount of additional weight. QLDC and the developer need to consider what employment in Wanaka will support 1,600 odd new dwellings. Studies carried out by QLDC have identified that majority of people decide to live in Wanaka because of the openness and freedom of space, quite different needs than Queenstown. The developer needs to consider the success of their Northlake Stage 1 where the 1 acre lots with the potential ability to be subdivided down to a minimum lot size of 1.800m2, this size of property is obviously highly desirable and is maybe where the market is at rather than a blanket 10 dwellings/ha approach.

My opinion is that Zones B1-B5 are more appropriate at 5 dwellings/ha with the surrounding zones C1–C4 being appropriate at a minimum of 1,500m2 given their location adjoining the Lake and Clutha River. The larger lot sizes adjoining the River and Lake potentially will minimize the impact upon the high amenity of the lake and river edge, but care will be needed to consider the bulk and height of these dwellings.

Traffic

Applying either the Wanaka Structure Plan baseline density or the Plan Changes higher proposed density to the site will have a significant impact on traffic within and outside the development.

Currently Aubrey Road is a highly desirable route into Wanaka for both cyclists and pedestrians with little available alternatives. As an Alberttown resident I have been commuting by bike on Aubrey Road for the past 8 years and are aware of many regular walkers and cyclists that the proposals Traffic Study does not reflect. Both Wanaka Primary and the Holy Family School have spent much time encouraging cycling and walking and there are regular family groups that cycle from Alberttown and its surrounds into school, particularly outside of the winter months. Looking at the proposals ‘Traffic  Generation and Distribution’ projections, in the morning and evening peak hours there will be a car entering the intersection of Aubrey Road and Outlet Road every 2.5 seconds (24/minute) which will have a significant impact upon the enjoyment and safety for cyclists and pedestrians.

A strategy on how to maintain a safe route into town needs to be developed before the Plan Change is consented.

Green Spaces / Walking and Cycleways

The Wanaka Structure Plan has long paid much lip service to maintaining green open spaces and linkages. Subsequent Plan Changes such as this one often refer to the Structure Plans intent for Green spaces and linkages in order to ‘tick the box’ but the reality is once a Plan Change is approved the Green spaces and linkages do not make it into the development plan. A good example of this is the Three Parks Development where the discussion documents and application material often referred to this objective but looking at the District Plans ‘Three Parks Structure Plan’ (12-171: May 2007) it is obvious this objective is lost with the Green Spaces and Linkages being piecemeal and token gestures with little amenity.

Plan Change 45 shows 5 vague suggestions of cycle and pedestrian routes connecting to the surrounding river corridor and ‘sticky forest’ but how they connect to green spaces and linkages within the plan change area and whether these notions remain meaningful and provide the desired objective is highly questionable.

Again the applicant needs to provide specific information on how they intend to satisfy this objective and ensure that it continues through the process to achieve a asset for both the development and wider community who may pass through the development.

Conclusion

I am generally supportive of the comprehensive combined Plan Change. More thorough analysis and design solutions are needed in the following areas;

  • Fairness of the Notification process in reaching the wider community.
  • Specific design approach and guidelines for proposed High density areas.
  • Reconsideration of the suburban blanket of 10 dwellings/ha with little amenity and more up to date analysis of growth projections/ demographic and market demand.
  • Consider the bulk and height of properties on the fringe of the Lake and River.
  • Strategy to provide safe alternative travel and leisure routes for pedestrians and cyclists both through and adjoining the Plan Change area.
  • Strategy to provide high amenity Green Spaces and linkages within the Plan Change area and practical connections beyond the site.

I am concerned that the Plan Change notice found on the QLDC website limits the ability to make further submissions to only those who ‘represent a relevant aspect of public interest (eg a community association or environmental group) or have an interest in the plan change that is greater than the general public’.  This indicates the intention is to not run a democratic process and I ask why QLDC want to exclude the rate paying public of Wanaka? Is this new policy of QLDC that will apply to all significant development of Wanaka and does this have any legal grounding? With this limitation of submissions and the poor level of notification you will not receive feedback from a more general cross section of interested individuals.

Office space to rent

39m2 1st floor air conditioned office with dedicated car-park on Reece Crescent, directly above Smiths City. Available late July 2013,  short or long term.

Shared facilities include kitchen, toilets, shower and roof terrace. Views out to Mount Iron and the Criffel Range.

I will consider rental of part of the floorspace if you are happy to share the space with others.

Please call or pop by Chris Norman Architecture to view.

[email protected]
027 663 6224

 

Chris Norman Architects
19 Reece Crescent, Wanaka

T. 03 443 8060
M. 027 663 6224
E. [email protected]