SIP Home UK - Structural Insulated Panels

FREQUENTLY ASKED QUESTIONS

What are SIPs?
SIPs are Structural Insulated Panels. They comprise of two 15 mm sheets of orientated strand board (OSB 3) autohesively bonded to a 110 mm CFC/HCFC-free rigid urethane core which has zero Ozone Depletion Potential (zero ODP), resulting in a panel with a thickness of just 140mm. These engineered pre-insulated building components serve as the inner-leaf of exterior walls and roof systems to give you loading and spanning capabilities not found in ordinary construction. SIP home Ltd can custom cut each panel to the desired house plan to ensure quality and speed of construction as well as providing an energy efficient home that cannot be matched by fibre glass batt insulation and timber framing.

These engineered pre-insulated building components can produce U-values as low a 0.10 W/m2.K. The result is a building product that is predictable, resource efficient and cost effective.

SIP’s are used as walls and roofs on all types of new build residential projects, small commercial buildings, schools, hospitals, holiday lodges, and extensions to existing buildings.

Is SIP technology new in the United Kingdom?
Yes, however the Kingspan TEK Haus Building System used by SIP home Ltd is recognised and approved by the Local Authorities and holds a BBA Third Part Accreditation Certificate. And, although new to the UK, SIP’s have been successfully used worldwide since the 1950s. The first SIP home was built in 1952 in Michigan, USA.

How much do SIP Panels Weigh?
Approximately 25 kg/m2.

Are SIP's Structural?
Yes. Also, tests indicate that SIP’s are significantly stronger than traditional timber frame construction and are comparable to medium density blocks in vertical loading tests. In fact, in the USA houses built with SIP’s have withstood the force of Class 6 hurricanes, such as Andrew, Hugo and Mitch unlike the traditional timber systems.

What type of construction can SIPs be used for?
SIP’s are used as walls and roofs on all types of new build residential projects, small commercial buildings, schools, hospitals, holiday lodges, and extensions to existing buildings

Why is the Kingspan TEK Haus Building System so much better?
•	Highly thermally efficient (U-values as low as 0.10 W/ m2.K can be achieved), low site wastage, fast-track and sustainable building solution;
•	Air tight construction – as low as 0.08 air changes per hour (approximately 1 m3/hour/m2 can be achieved);
•	More controllable indoor environment than traditional build;
•	Low site wastage as systems are made up in the factory;
•	System naturally incorporates room in roof, so it is an excellent solution for developments that are influenced by Planning Policy Guidance Note 3 (PPG3), i.e. developments on brownfield sites;
•	Fast and safe - 150 m2 floor area house can be erected in as little as 2-3 days (excluding foundations and finishing);
•	For contractors, faster build time can mean quicker critical path to completion and therefore an earlier start to the next project;
•	CFC/HCFC-free with zero Ozone Depletion Potential;
•	Egan compliant.

How is the Kingspan TEK Haus Building System Egan Compliant?
•	Reduced construction time;
•	Predictable – the Kingspan TEK Haus Building System is relatively simple to install and as such it is easier to predict project completion times;
•	defects are vastly reduced due to factory controlled manufacture of the system;
•	accidents are kept to a minimum as only registered Kingspan TEK Haus Contractors can install the system;
•	productivity is high and consistent; and
•	turnover and profits – the speed of build allows for a reduction in working capital and cash-flow.

Uptake

Why aren't SIP’s more widely used in the UK and Ireland?
Lack of awareness and conservation are the main reasons. The new Building Regulations / Standards which came into effect in 2002 in the United Kingdom and are due in Republic of Ireland in 2003 challenge many traditional construction systems. People are now looking at ways of meeting the new requirements economically.

Thermal efficiency combined with the speed of build and the low site wastage makes SIP’s a very cost effective way of exceeding the new Building Regulations / Standards. In addition to this, the extremely low U-values that can be achieved by using SIP’s (as low as 0.10 W/ m2.K in roofs and walls) means the system will also easily meet the U-values that are expected to be set in the next changes to the Building Regulations / Standards in 2008 and beyond.

Thermal Efficiency

How energy efficient are Kingspan TEK Haus SIP’s?
Thermal conductivity of the CFC/HCFC-free rigid urethane core is 0.025 W/m.K, with 0.14 W/m.K for the OSB 3, meaning each panel has an R-value of 4.601 m2.K/W. The total wall thickness of the Kingspan TEK Haus Building System, including the external weather protection, can be as little as 194 mm. This is the approximate equivalent in thermal performance, of 405 mm in masonry or 448 mm in timber frame.

How are the R-values and thermal conductivities calculated?
The R-values and thermal conductivity (Ö -value) quoted for the CFC/HCFC-free rigid urethane insulation core of the SIP’s panels in the Kingspan TEK Haus Building System are based on the procedures for the determination of the aged values of thermal resistance and thermal conductivity for the insulating component. These procedures are laid down in the latest harmonised European standard BS EN 13165, using the 90:90 principles of statistical analysis.

Comparison with alternative products may not be appropriate unless the same procedures have been followed.

Why do Kingspan TEK Haus SIP’s have better (higher) R-values than conventional framing?
•	The 110 mm CFC/HCFC-free rigid urethane core has extremely good insulation value and does not allow movement of air within the wall. It will not sag or physically deteriorate over time unlike many conventional insulating materials.
•	The Kingspan TEK SIP’s create a very tight structure with little opportunity for air leakage.
•	Consider also that well over 630 mm out of every 10m of wall (15.9%) in a conventional framed house is not protected by insulation due to the timber frame components.
•	The SIP’s technology, upon which the Kingspan TEK Haus Building System is based, means the insulation layer is not interrupted by studwork and therefore there is less thermal bridging and a better thermal resistance. There are however some bridges where timbers are used to support point loads etc.
•	Also, the 110 mm CFC/HCFC-free rigid urethane insulation core does not allow movement of air within the wall and will not sag over time unlike many other insulating materials. Applying expanding urethane sealant to the panels’ unique jointing system creates a very tight structure with little opportunity for air leakage.

Are builders and developers using SIP’s today?
Yes, already in the UK there are a large number of completed projects around the UK with many more on site or planned for the future.

Most people who see the system assembled are impressed with the high quality and strength of SIP’s, as well as speed of construction, and it is rare to hear a complaint from anyone who has worked with the material.

Environment

Why are SIP’s more environmentally responsible?
•	High insulation value translates to lower energy (fossil fuel) consumption and CO2 emissions, helping to negate global warming while giving you lower heating bills;
•	Zero Ozone Depletion Potential (zero ODP), protecting stratospheric ozone and reducing UV damage;
•	Factory made system with minimal site wastage;
•	Minimal job site wastage means less landfill use;
•	OSB 3 is derived from routine thinning from managed plantations;
•	Lower reported energy costs due to the air tightness and overall excellent thermal efficiency of the system when compared with traditional build systems.

Are SIP’s sustainable over the lifetime of the property?
•	It is widely recognised that there are four main global sustainability issues: global warming, non-renewable resource depletion, toxic pollution and ozone depletion, and that these global issues far outweigh any local sustainability issues in their need for immediate attention and potential impact from inaction.
•	Recent studies have shown that the first three issues are essentially one. The extraction and consumption (burning) of fossil fuels is by far the most significant contributor to global warming, non-renewable resource depletion and toxic pollution.
•	60% of fossil fuels are used to heat buildings in the UK, half of this in housing. Therefore as far as housing is concerned sustainability comes down to two main issues: reduce fossil fuel use and specify zero ODP products.
•	By far the most economical method of reducing fossil fuel use is to reduce space heating demand. The investment for renewable energy sources only becomes convincing once space heating demand is minimised as capital costs are prohibitive to most.
•	There are two main methods of reducing space-heating demand: reduce heat losses through the building fabric and reduce heat losses from unintentional air-leakage.
•	The former has been the subject of Building Regulation for 30 years but still has a long way to go before an optimum level is attained. It is estimated that U-values of 0.1 W/m2.K would be the practical optimum. We may have to wait 20 years for Building Regulations to demand this.
•	Building Regulations are only starting to attend to the issue of air-leakage, which becomes more significant an effect as U-values are reduced, but it is likely that Building Regulations will come to focus more on air-tight constructions over the next 20 years as U-value get closer to the optimum.
•	Air-leakage rates of 1 m3/m2/hour and U-values of 0.1 W/m2.K can be achieved with the zero ODP Kingspan TEK Haus Building System used by SIP home Ltd.

Manufacture

How are SIP’s made?
SIP’s in the Kingspan TEK Haus Building System are manufactured by autohesively bonding two 15 mm sheets of OSB 3 bonded to a 110mm CFC/HCFC-free rigid urethane core resulting in a panel with a thickness of just 140 mm. The process is fully automated, this yields consistent quality and tolerance. N.B. There is no adhesive used in the lamination of the OSB 3 to the insulation core.

Why does Kingspan TEK Haus Building System use OSB 3 instead of plywood?
Using OSB 3 actually produces a stronger panel than plywood and is available in longer lengths. In addition, it is more stable than plywood, especially when exposed to moisture and much more could be regarded as being sustainable utilising the routine thinnings from managed plantations. OSB 3 is available in a wide range of sizes and at a lower cost than plywood, which allows us to produce a more affordable SIP.

Can you get a thinner panel for internal walls?
Not at the moment. Internal walls are constructed in the usual manner with timber or metal stud partitions. Internal walls constructed from Kingspan TEK Haus panels are only provided as structural elements, i.e. beneath a point-load position or to carry walls above.

Accessories

Do SIP’s Come Pre-Framed With Windows and Doors?
Your choice. Design and supply of structures by SIP home Ltd is flexible. SIP home Ltd can supply and fix a whole range of windows and doors into the SIPs panels either in our factory or on site. We can also prepare the openings for a third party to supply and fit.

Do SIP home Ltd offer options for the external finishes?
Yes. SIP home Ltd have a number of standard options from natural stone, brick tiles, polymer renders, timber cladding and metal claddings. Alternatively, if you have a specific design using other materials, SIP home Ltd will investigate its compatibility with the Kingspan TEK Haus Building System.

Strength

Why are SIP’s so much stronger?
SIP’s are a structural composite, similar to an 'I'-beam. The skins act like the flanges and the rigid core is similar to the web. The two 15 mm OSB 3 boards, which are autohesively bonded to the CFC/HCFC-free rigid urethane insulation core, work together, rather than against one another. This composite assembly provides stiffness, strength and predictable responses, i.e. in shear tests. Not only do test results show panels are stronger, but real life natural disasters have proven it time and again. The Great Hanshin (Kobe, Japan) and North Ridge earthquakes, hurricane Andrew, a Colorado tornado, a Portland gas explosion and an Omaha fire, have done more to prove SIP strength to the homeowners than the all of the scientific tests.

Structurally, can panels replace timber-frame and masonry construction?
Yes. Tests performed show panels can, and do, outperform standard timber frame construction.

Fire

How does the Kingspan TEK Haus Building System react to fire?
The Kingspan TEK Haus Building System exceeded the Building Regulation requirements with regards to fire resistance and achieved 54 minutes fire resistance and structural integrity (when internally lined with 12.5 mm standard plasterboard) and 73 minutes fire resistance and structural integrity (when internally lined with 12.5 mm fire resistant plasterboard) in accordance with BS476: Part 21: 1987 ((Fire tests on building materials and structures). Methods for determination of the fire resistance of load bearing elements of construction to the Building Regulations).

Durability

Is the Kingspan TEK Haus Building System vulnerable to insects and pests?
The CFC/HCFC-free rigid urethane core of the SIP panels in the Kingspan TEK Haus Building System resists attack by mould and microbial growth and does not provide food value to vermin.

What is the life expectancy for the Kingspan TEK Haus Building System?
When designed and installed correctly, the Kingspan TEK Haus Building System a life of at least 60 years can be expected.

Planning

Will I have any planning problems using SIP’s?
•	The approval process for the new Kingspan TEK Haus Building System is as smooth as the construction process itself with our Local Authority Building Control Partnership now in place to fast track approvals for the system.
•	Should you wish to take advantage of the partnership, Herefordshire Council will provide the approvals for the Kingspan TEK Haus Building System plans on behalf of other building control departments throughout the UK.
•	For the Building Control Officer the partnership saves valuable time as Herefordshire Council Building Control, who are familiar with the Kingspan TEK Haus Building System, can carry out the approvals. For volume housing projects, the partnership not only speeds up approvals but can also save money through favourable partnership rates, when one design is being used for more than one construction.
•	BBA and IAB certification of the system means that there are no concerns with regard to the suitability of the construction process.

Design

Who can design buildings using SIP’s?
SIP home Ltd will work closely with your Architect to develop the most efficient design using SIP’s. If you do not have an Architect, SIP home Ltd can carryout the design and construction management from concept through to completion including obtaining the necessary planning and Building Control Approvals.

Will using SIP panels limit the design?
No, we manufacture schemes to customised designs, sometimes geometrically challenging that could not be achieved with any other form of construction. Because of the structural requirements, some designs may end up more costly than others, and we will advise if there are any particularly costly features that could be altered.

Cost

How do SIP’s compare to a timber frame?
•	The thermal efficiency of the Kingspan TEK Haus Building System used by SIP home Ltd can offer dramatic energy cost savings over the lifetime of the building
•	On the basis of equal performance i.e. a U-value of 0.20 W/m2.K, the cost of a Kingspan TEK Haus Building System would be considerably lower than an equivalent timber frame construction.
•	Labour cost should be slightly less expensive, due to shorter construction time and also can result in follow on trades starting work earlier, in some cases even as soon as the ground floor is complete.
•	When the house is built for the purpose of renting or for sale, the shorter construction time, as a result of using the Kingspan TEK Haus Building System, usually enables tenants to move in sooner and therefore resulting in a quicker return on your investment.
•	The Kingspan TEK Haus Building System requires no maintenance and when used with external finishes recommended by SIP home Ltd, maintenance cost are vastly reduced again reducing considerably the ‘Whole Lifetime Costs’ of the building.

How much extra cost is it to build a house with room in roof?
Nothing when using the SIPs because the roof, as with the rest of the system, comprises Structural Insulated Panels (SIP’s) which allow the roof space to be fully utilised.

How does the Kingspan TEK Haus Building System save so much on labour?
The cutting is done in the factory. Determining what cuts to make is done on a computer screen. Easily recognised components are shipped to the site for assembly, rather than waiting for interpretation of blue prints. SIP’s also come in much larger dimensional sizes than other building materials.

When on site, a team of 4-6 can put up a Kingspan TEK Haus Building System very quickly. Once constructed the sub contractors have a dry, thermally efficient envelope to work in meaning quicker installation of services and drying times for plastering etc and consequently, quicker project completion.

How much wastage will have to be budgeted for from Kingspan TEK Haus Panels?
Negligible. Because the Kingspan TEK Haus Building System is factory made there should be no site wastage from the panels. This results in more efficient use of materials and also lower landfill fees because of negligible waste material from the system on site.

Mortgages

What about getting a mortgage for when building using the Kingspan TEK Haus Building System?
The Kingspan TEK Haus Building System has NHBC Approval and most lenders are able to offer mortgages.

Time for Build

How long does it take to erect the Kingspan TEK Haus Building System?
Depends on the size and complexity of the scheme but can be as little a one day. A typical three or four bedroom house can be constructed to be wind and water tight in 3 to 4 days.

Ground Floors

What ground floor construction can be used with the Kingspan TEK Haus Building System?
Any construction can be used, however the foundations must have very tight tolerances of +/- 5mm to ensure the smooth erection of the building system.

Installation

Who can build the Kingspan TEK Haus Building System?
SIP home Ltd is a registered Kingspan TEK Haus Building System installer. Our installation team has over 25 years experience working with unitised engineered building systems. We are also approved and registered with many external and internal finish suppliers making for a complete package – with confidence.

How are SIP panels joined together?
SIP’s in Kingspan TEK Haus Building System connect by a twin 50 mm deep x 15 mm wide routed channels which accommodate a two 15 mm x 100 mm OSB 3 splines. Expanding urethane sealant has to be applied in the central channel before the splines are installed. This jointing system in conjunction with the expanding urethane sealant enables the Kingspan TEK Haus Building System to be very airtight.

Can I cut an opening in the panel at a later stage if I want to move a window or door?
Alterations can usually be accommodated during the construction process if required. Prior approval in writing from SIP home Ltd will be required. Alterations following completion of the building are possible but more difficult and should, where possible, be carried out by SIP home Ltd who has access to the original design plans. N.B. A structural engineer must verify all alterations.

If the panels or floors get wet during erection, will it affect them long term?
Wall and roof panels should be protected from the elements as soon as possible. A high quality breathable membrane is incorporated on each project. The first floor and subsequent floors are supplied with a pre-coated polythene sheet, which is weather proof and non-slip.

How do I install kitchen units, boilers and shelving?
Cabinets can be anchored anywhere along the surface of the panel. Boilers should be hung with rawl plug interset fixings or equivalent. All other items can be mounted with Rawl-in-One / Rawlbloc fixings or equivalent. See specification details for more information.

Services

How do you install wiring?
Where possible run wiring through internal studs partitioning walls. However, where wiring has to be run up TEK Haus walls there are two ways it can be done:

Option 1 – Double Layer Plasterboard
Mechanically fix the first layer of 9.5 mm or 12.5 mm plasterboard to the Kingspan TEK Haus Building System wall panel at 300 mm centres using plasterboard screw fixings, cutting away plasterboard where the wiring is to be situated. Having installed the wiring along with an IEE approved metal guard, mechanically fix the second layer of plasterboard over the first layer using plasterboard screw fixings at 300 mm centres. 25mm deep metal back boxes can be used for electrical fittings screwed directly back to the panel wall.

Double layer plasterboard is an excellent option, especially if you are building the house to sell on or rent, because there is no service cavity and they have a very solid sound unlike some timber frame walls, which often sound hollow. This option also has added acoustic and fire properties.

Option 2 – Single Layer Plasterboard on Timber Battens
Fix 10 mm timber battens at 600 mm centres and install the wiring between them along with an IEE approved metal guard. Then mechanically fix 9.5 mm or 12.5 mm plasterboard over the battens. (See next section for requirements for fixing surface mounted pipes when using a single layer of plasterboard on a 10 mm batten.

How do you install plumbing?
•	Plumbing can be installed in the same way as any other building system.
•	The Kingspan TEK Haus Building System can use the same floor construction as any other system and consequently the ground floor plumbing depends on the floor type.
•	At first floor level, the Kingspan TEK Haus Building System uses TJI joists meaning that pipes can be installed in the same way as any other system.
•	When plumbing appliances have to be run up the wall, where possible run pipes through internal studs partitioning walls.
•	When plumbing has to be run up a Kingspan TEK Haus Building System wall panel or appliances such as radiators have to be fixed to the Kingspan TEK Haus Building System wall panel there are two options:

Option 1 - Double Layer Plasterboard
•	Surface mounted pipework on double layer plasterboard - pipe clips can be fixed with clout nails through the double layer of plasterboard and into the TEK Haus panel.
•	Pipework within double layer plasterboard wall - mechanically fix the first layer of plasterboard (thickness dependant on depth of pipework and clip) to the Kingspan TEK Haus Building System wall panel at 300 mm centres using plasterboard screw fixings, cutting away plasterboard where the pipework is to be situated. Having fixed the pipe clips to the TEK Haus panel with clout nails and installed the pipework in the clips, mechanically fix the second layer of plasterboard over the first layer using plasterboard screw fixings at 300 mm centres.
•	Surface mounted radiators on double layer plasterboard – radiators can be fixed in accordance with manufacturers instructions through the double layer plasterboard and into the TEK Haus panel.
•	Using double layer plasterboard combined with the solid Kingspan TEK Haus Building System panel means there are no restrictions on where radiators can be situated. Also there is no extra labour involved, unlike timber frame where noggins have to be installed for fixing units such as radiators.

Option 2 - Single Layer Plasterboard on Timber Battens
•	Surface mounted pipework on single layer plasterboard - pipe clips can be fixed with clout nails through the plasterboard and timber battens and into the Kingspan TEK Haus Building System wall panel.
•	Pipework within single layer plasterboard wall on timber battens - mechanically fix the plasterboard to battens that are deep enough to accommodate the pipe and clip. The clips that carry the pipework are fixed directly to the Kingspan TEK Haus Building System wall panel with clout nails.
•	Surface mounted radiators on single layer plasterboard wall on timber battens - noggins to be fixed in between the vertical battens so radiators can be fixed through the battens into the Kingspan TEK Haus Building System wall panels.

What ventilation systems can be used with a Kingspan TEK Haus Building System and is it necessary?
The Kingspan TEK Haus Building System can be considerably more airtight than conventional constructions and it is widely accepted that healthy buildings require a minimum air leakage rate of 0.5 air changes per hour. Therefore additional ventilation of the Kingspan TEK Haus Building System may be a sensible and beneficial addition to a Kingspan TEK Haus Building System. The Building Regulations encourage architects and builders to ‘Build tight, ventilate right’, and introducing controlled ventilation is considered good practice in energy terms. The methods are common in use.

Mechanical Ventilation (with Heat Recovery) Systems - these systems bring fresh air into the home or building and exhaust the moisture laden or stale air to the outside. With the addition of heat recovery the system can recover heat from outgoing and preheat incoming air. Often they can be combined with filter systems or other fresh air devices. Please contact any supplier of domestic scale mechanical ventilation with heat recovery systems for specific sizing of equipment and the environmental and improved in-door air quality benefits associated with these systems.

Passive Stack Ventilation Systems - controlled passive stack ventilation operates on simple natural principle.

Stack effect - Ducts run from 'wet' rooms - kitchens, bathrooms etc - up to roof terminals. Warm moisture-laden air rises up the ducts by the stack effect, requiring no electric fan or power source.

Fresh air - Wall or window inlets provide a flow of replacement fresh air into the building as required.

Planned airflow - The position of inlets and extracts ensures that air always moves from 'dry' rooms to 'wet' rooms, where it is extracted.

What is the best heating system for the Kingspan TEK Haus Building System?
•	Buildings constructed using the Kingspan TEK Building System are cheap to run from the viewpoint of heating bills because they are so energy efficient.
•	You can use any conventional heating system but sizing and controls are important. Heating systems can be 'down-sized' considerably and even eliminated altogether, as heating demand can be very low or negligible. Controls are important so as to avoid overheating - a normal domestic heating regime will cause a TEK Haus to overheat.
•	TEK Haus can also act as a stimulus to think outside the box with regards to heating systems. Wet radiators and associated pipe runs can be a thing of the past if thought is put to a combined ventilation and heating strategy with the introduction of a small fan coil into a mechanical ventilation unit.
•	Whatever heating system you chose, we advise that you should have it engineered to suit the heating demands of a TEK Haus rather than a conventional build.

Finishes

What finishes can I use with the Kingspan TEK Haus Building System?
Some of the many finishing options that you have are external render onto appropriate carriers, brick slips, feather edge boarding and tile hanging, as well as building an outer leaf of brickwork or stone with the Kingspan TEK Haus Building System shell forming the inner leaf.

What type of roof finishes can be used with the Kingspan TEK Haus Building System?
You can use traditional tiling methods with counter battens and tiling battens, shingles, single ply, profile metal sheeting. Consult our technical department at an early stage, as loading design values must be calculated for when designing the system to suit your project.