There are many reasons people are pursuing more environmentally friendly and sustainable builds. These include:

• Social Consciousness
  Homes in Europe account for 40% of total energy consumed. With dwindling fossil fuel stocks and the associated C02 emissions generated from burning these fuels, people realise we need to look at the alternatives: reducing fuel consumption and looking at environmentally friendly alternatives.
• Lower Running Costs
  Building an energy efficient home will reduce running costs and energy bills. A range of measures can be introduced, some small whilst others major. Life cycle costs need to considered. This means that the effects of some methods of improving efficiency can be immediate whilst others will be spread out over the life cycle of the build.
• It’s the Law
  Regulations have been introduced into law that stipulate that new homes need to be more energy efficient. The 2008 revisions to Part L of the Building Regulations have required that all new dwellings achieve at the very least a B1 rating.

The advantage of a new build home is that every measure can be taken to improve the energy efficiency of your house. Below are methods of creating a more energy efficient home.

Energy used in driving from place to place can amount to a significant proportion of a household’s total energy consumption. By locating new houses near to workplaces, schools, public transport routes, etc., transport energy consumption can be reduced.

In some, mainly rural locations there may be potential for renewable energy sources other than solar, for example hydropower, wind power, wood, biogas or heat which can be extracted from the ground or sea. The possibility of obtaining heat from a combined heat and power plant or group heating scheme may also influence the selection of a site.

If your site allows it, it is preferable to make use of a south-facing aspect to let winter sunshine heat up your home, a theory known as passive solar design. It works best where you have an internal heat store. If you’re using solar-heat gains you will need some masonry mass to hold the heat.

A concrete slab with tile covering in front of a south-facing window will hold heat well, but there is not much benefit in putting that oppo¬site north-facing windows. Put the mass where it will do some good and minimise cement use.

However, care should be taken not to overglaze the southerly aspect, as this can cause problems with overheating. In truth, passive solar design isn’t critical in the Irish climate: it works best in spring and autumn.

By selecting a location sheltered from the wind, heat loss from the building can be reduced. Shelter can be provided by nearby trees, adjacent buildings or surrounding hills. If no such shelter exists, it can be provided in time through planting trees or shrubs.

A compact building form of minimum surface-to-volume ratio is best for reducing heat loss. However, a rectangular building with one of the longer facades facing south can allow for increased passive solar heating, day-lighting and natural ventilation. As well as reducing energy costs, sunny south-facing rooms also have high amenity value.

Projections such as bay and dormer windows should be kept to a minimum, since by increasing the surface-to-volume ratio of the building, they will increase heat loss.They also tend to be more difficult to insulate effectively.

Pitched roofs should have one slope oriented south to allow for optimum performance of a roof-mounted or roof-integrated active solar heating system.Even if such a system is not planned during construction, it may be installed at some stage during the life of the building.

Traditionally, Irish builders haven’t given a moment’s thought to draughtproofing houses, other than fitting draught strip around the doors and windows. However, an air tightness test is now a requirement of the BER and the higher the air tightness rating, the better your overall BER will be.

To get an airtight house, you have to pay close attention to the detailing and the junctions, and avoid any unnecessary penetrations. Both masonry and framed constructions are capable of getting good air pressure test results, but some techniques perform very poorly.

Having gone to all this trouble to seal the house from unwanted drafts (thus losing valuable heat), you then have to pay close attention to providing good ventilation so that indoor air quality doesn’t suffer. Most of the low-energy homes around the world use mechanical ventilation systems, with added heat recovery, so that any heat losses are minimised.

Heat Recovery Ventilation gets rid of the old stale air inside your home and replaces it with fresh filtered and pre-heated outdoor air. As the warmer indoor air is sent out - a heat exchanger inside the ventilator extracts the heat and uses it to pre-heat the incoming fresh air.

The layout of rooms and window openings will also affect your BER. For example, is there a direct path for air flow from the front of the house to the rear?

In Mediterranean climates, cooling houses in summer uses more energy than heating them in winter. Whether or not our climate trends this way, it would be remiss not to pay attention to the issue of cooling. In fact, good insulation and airtightness levels help a great deal in this respect, as the heat of the midday sun is largely kept out of the house.

The best designs use some form of shading to keep the summer sun off the glazing. Planting decid-uous trees in front south facing windows will let sunlight in during winter and provide dappled shade in summer.

Thermal mass is the ability of energy efficient materials to store heat. If thermal mass is to be designed into a home, it is best included in floors and internal walls, since these can be warmed during winter days and release heat in the evening. These surfaces can also be protected from the sun in summer with the use of appropriate windows and eaves.

There is no such control for the roof, so it is generally considered good practice to use low thermal mass in roofing systems. A roof made from energy efficient materials is strong and light weight. It has a low thermal mass, which means it cools down fast on a hot night and improves the comfort within the home.

Walls
We are still not using enough. We are still nowhere near the thicknesses used in Scandinavian homes, which is what is required if we are to reduce heat loss to a bare minimum. One of the problems is that we mostly build homes with masonry cavity walls, and it’s difficult (though not impossible) to increase the widths of the cavities to the levels required.

However, the construction of some passive homes has shown that you can pack 300mm of insulation into a cavity wall construction and not suffer any unexpected consequences — so it looks as though there is a way forward for masonry construction in the brave new world of zero-carbon developments. It’s just that, at the moment, such a level of insulation is still exceptionally rare.

The alternative approach is to look for different construction systems that promise much lower U-values. Timber frame is the best-known one, but even here the standard Irish timber frame wall, at 140mm thickness, is still someway light of what is required for an ultra-low-energy home. Timber frame can, however, be fairly easily adapted to greater width demands. Other build methods, such as SIPs and ICF (both popular with selfbuilders), offer potential routes to getting ultralow- energy structures.

Floor
Like walls, improving the U-value of a floor is best done at design stage when all you need to do is increase the amount and/or quality of the floor insulation.

Loft
Loft spaces also need good quality insulation. 270mm of insulation in your loft can save around 20% of your heating costs.

Windows have been at the forefront of the move towards greater energy efficiency. They have an unusual role in all this because there are times of the day when windows can be net contributors of heat, but this is greatly outweighed by the long dark winter nights when they become a noted weak point in the thermal envelope surrounding a house.

To counter this, we have seen numerous improvements in the ways we build windows. What would have passed for state of the art 20 years ago would now fall a long way short of passing basic Building Regulations and the maximum allowable U-values for windows are set to get lower still in future.

One of the big questions here is whether we should now switch to triple-glazing. In Sweden and Canada it’s commonplace, but these are much harsher climates than ours and it’s still not entirely clear that tripleglazed windows make much sense in Ireland, as they are much more expensive to produce and the energy benefits are marginal at best.

Don’t just assume that triple-glazed windows are necessarily more energy efficient than double-glazed ones: there are other factors involved. It is not just the thickness of glazing but the type of glass used, the air between panes, etc. that will affect the U-value.

An alternative approach is to use an energy-rating scheme which takes account of not only the heat-loss characteristics but the solar gain and the airtightness of the whole assembly. Make sure you only purchase windows that have all the relevant U-value information.

Whereas windows routinely take up 20-30 per cent of the available wall space, and thus have a huge bearing on overall energy performance in a building, external doors are far less significant. Nevertheless, it’s no longer something that can be ignored. The problem here tends to be solid timber doors, which have a U-value of around 3.0, much higher than the level demanded for windows (currently 1.8).

Doors made of other materials tend to have hollow cores, which can be readily filled with insulation. The regulations allow you to average the total Uvalues of all joinery, and therefore you can offset using timber doors with lower Uvalues for windows. In theory you can even offset single-glazed windows with ultraefficient doors etc.

The embodied energy of a product is the energy used to produce it, and includes energy used in extracting raw materials, processing and transport, e.g. Irish-grown timber will incur lower transport energy use than timber imported from overseas.

The embodied energy of a house is typically over five times its annual energy consumption and therefore equates to approximately 5-10% of the total energy consumption during the life of the house.

The building materials selected should have minimum environmental impact during their entire life cycle, including manufacture, use and disposal. Building components should be designed for long life and durability, and ideally should be recyclable at the end of their operating lives.

Installing certain types of Renewable Energy Systems are a requirement if you wish to receive a high BER. For example, to achieve a B1 rating, at least 4m2 of solar panels must be installed.

Renewable technologies consist of the following:

• Solar Heating
• Solar Photovoltaic
• Heat Pumps
• Biomass
• Wind Turbine

Active Solar Heating is one of the primary ways for buildings to use solar energy. This technology uses solar collectors to transform solar energy into heat to provide space and/or water heating. Solar water heating is the most common application of active solar thermal in Europe. A correctly sized solar water heating system can cover 50-60% of your hot water heating requirement with free solar energy.

A Solar Thermal system providing space and water heating is generally referred to as a solar combisystem. It is generally sized to cover 30 to 40% of the annual heating requirement of a house in Northern Europe. In Ireland, a solar combisystem using air as a heat transfer medium is gaining in popularity. It has the advantage of combining solar heating and ventilation through the same system. It is particularly suitable for low-energy houses.

‘Photovoltaic’ means electricity from light. In essence, photovoltaic systems use daylight (not necessarily direct sunlight) to convert solar radiation into electricity. The light which shines on the PV cells creates an electric field causing electricity to flow. The greater the intensity of the light, the greater the flow of electricity.

Photovoltaic systems use semiconductor materials to convert solar energy into electricity. This technology is widely used in consumer products such as solar calculators, watches or garden lights, and is increasingly used as a cost-effective solution in Ireland for stand-alone applications where a grid connection is too expensive (e.g. parking meters, caravans or remote holiday homes).

Solar PV can also be used to provide free solar electricity to houses as well as for commercial and industrial applications. Recent developments in regulation mean that it is now possible to connect solar PV systems to the grid, opening up a new era for solar PV in Ireland.

Photovoltaic (PV) panels are not very efficent (7%-14%) but are useful for generating electricity in remote areas. If combined with a wind turbine then the majority of ones needs can be met.

Heat Pumps are used for space heating and cooling, as well as water heating. Geothermal heat pumps operate on the fact that the earth beneath the surface remains at a constant temperature throughout the year, and that the ground acts as a heat source in winter and a heat sink in summer.

Other heat pump types are available such as air and water source. These operate on the same principle indoors but the method of collecting heat is different for each type.

Biofuel is a term used for biomass which has been prepared/upgraded to provide bioenergy. Wood fuelled heating systems generally burn wood pellets, chips or logs to power central heating and hot water boilers or to provide warmth in a single room.

There are two main ways of using wood to heat you home:

• A standalone stove burning logs or pellets to heat a single room. Some can also be fitted with a back boiler to provide water heating as well.
• A boiler burning pellets, logs or chips connected to a central heating and hot water system.

Many residential areas are not suitable for wind turbines as buildings and trees shade the wind and create turbulence which can reduce the efficiency and lifespan of a turbine considerably.

Generally speaking, the ideal location is on top of a high mast on a south westerly facing hill with gently sloping sides surrounded by clear countryside which is free from obstructions such as trees, houses or other buildings. Here the wind flows relatively smoothly and steadily enabling it to drive wind turbines with greater efficiency.

Wind turbines operate less efficiently in areas where obstacles interfere with wind flows. It is very important to understand and account for these reduced efficiencies when considering the use and economics of wind turbines in such areas.

However, such areas, with less than ideal aspect and local conditions, may, with a good quality turbine system, have a sufficient wind resource to make an installation worthwhile. The predominant and most energetic winds in Ireland typically come from the southwest and west, so it is especially important that there are few or no obstacles to the turbine in these directions.

If looking at Oil or Gas boilers, you should ensure that the boiler complies with the EU boiler efficiency directive. In the case of gas boilers, you should consider condensing boilers,which cost a bit more but are highly energy-efficient - around 12% more efficient than modern conventional boilers.

If you are constructing a chimney with an open fire in your dwelling it is considered to be a secondary space heating system providing 10% of the space heating need (regardless of how much you actually use the fire).

Open fires are very inefficient (30% efficiency) so you can improve the BER in this case by replacing the open fire with a more efficient heater, e.g. a high efficiency wood-pellet stove (65% efficiency) with its outlet flue sealed to the chimney.

If a fireplace must be installed, an ‘underfloor draught’ air supply (a small duct or pipe installed within the floor and connecting the outside air directly to the fireplace) can help to reduce the amount of warm internal air escaping through the chimney.

Although heating water from solar panels is by far the best way to generate hot water, it is generally more energy-efficient to heat water using an efficient boiler or other fuel-burning appliance than with an electric immersion heater.

The hot water cylinder should be well-insulated; factory applied insulation is generally more effective and durable than a lagging jacket.

As well as providing space heating, combination ‘combi’ boilers supply hot water directly to the taps, thus avoiding the losses associated with storage in a hot water cylinder.

By locating the heating and hot water systems, including pipework, entirely within the insulated building shell, heat losses can become heat gains.

Ensure good ventilation to the boiler and take account of fire regulations. Attention should be given to minimising the lengths of pipe runs and associated heat losses.

Room thermostats provide heat until the desired temperature is required.

Hot water cylinder thermostat can reduce the temperature of your stored hot water and save yourself money, while preventing the water getting excessively hot too.

Thermostatic radiator valves provide control over the temperature of each room separately which can save energy.

Controlling heating on a timer not only provides a comfortable environment but ensures heating is used at the times you require it. No more going out and forgetting to turn the heating off.

A Boiler Interlock is an arrangement whereby if there is no space heat demand and no water heating demand the boiler is switched off. How you do this depends on what type of heating system you have.

In a system with a regular boiler you need a cylinder thermostat, a room thermostat and motorized valves. These must be wired up in a particular way to achieve the interlock.

In a system with a combination boiler you just need a room thermostat to achieve the interlock.

If you do not have an interlocked system the efficiency of the boiler is reduced by 5% which has a bad effect on the BER value.

Energy efficient light bulbs cost between €1.50 and €5, using less electricity and last for several years. Make sure your fittings are designed to accommodate energy efficient light bulbs.

Energy saving light bulbs use a fifth to a quarter of the electricity of ordinary bulbs to generate the same amount of light. So where you'd normally use a 60W bulb, you'll only need a 13-18W energy saving recommended equivalent.

Current Building Regulations state (in part L1 of the regulations) that a certain number of dedicated low energy light fittings must be installed within new build homes and extensions.

These fittings must have integrated ballasts within the fitting to ensure only low energy bulbs can be replaced (thus stopping the installation of standard, non-efficient, incandescent lamps in to the lamp holders).

The following is a guide to recycling housing waste. Construction is facing enormous pressure to find ways to conserve and make best use of our increasingly scarce natural materials.

One way to do this is to reuse, reclaim or recycle materials, the major source of which is from demolitions. In the past, building regulations were confusing. But providing the materials are suitable for their intended purpose, there is no reason why you can't reclaim or recycle them in line with building regulations. By reducing, reusing, recycling, and reclaiming at least 5% of building waste you can save €1,000 - €12,000.

Before starting work you need to consider the following:

• Use local materials
• Keep the plan shape as regular as possible
• Use the right products - not purpose made
• Deliver materials at the last minute - less damage caused by storage and less double handling
• Store topsoil and subsoil for reuse - don't pay to take away and import new
• Consult early with a building control surveyor, which may mean less excavation and concrete in foundations and floors
• Design with dimensional co-ordination in mind
• Shred plasterboard off-cuts and mix with soil
• Shred timber waste for mulching around trees and bushes
• Sort waste and off-cuts for reuse and recycling
• Order materials carefully to reduce excess

Generally speaking, sustainability is a worthwhile aim, and in house building, good economic sense. For example, a skip full of waste is a skip full of money. To add insult to injury, you will have to pay to remove it from site.

Using local materials will reduce transport costs and be more in keeping with the existing building. It is also good practice in conservation areas and you are more likely to get planning permission.

An A1 rated home is achieved where the primary energy used is between 0 and 25 kilowatt hours per square metre per year. A2 and A3 ratings are where the dwelling has a primary energy consumption of 26-50 and 51-75 kWh per square metre per year respectively.

With the high levels of thermal insulation in an A-rated home, heating in summer months will be an important consideration. Heavy buildings absorb solar gains better, and can stay at comfortable temperatures for longer than lightweight buildings.

Concrete homes can uniquely benefit from having medium or heavy thermal mass. Apart from improving summer comfort, they can reduce the need for cooling, thus improving energy performance. Alternatively, if rapid heat build-up is desired, insulated dry lining to the inside face of concrete block walls can be highly effective.

The energy savings from different conservation measures vary, depending on the dwelling type, size - large or small, design – compact or open plan, heavy or medium thermal mass. Furthermore, the savings from any given measure vary depending on the exact set of measures implemented.

Some measures are more cost effective than others. Energy efficient light bulbs always win. However, planning a layout for good passive solar performance must be done at initial design, and many construction improvements must be incorporated during initial build. It pays to get it right at the beginning. From an environmental viewpoint, the time to reduce carbon dioxide emissions is at design stage.

A B1 rated home is achieved where the primary energy used is between 76 and 100 kilowatt hours per square metre per year. B2 and B3 ratings are where the dwelling has a primary energy consumption of 101-125 and 126-150 kWh per square metre per year respectively.

The following table gives a guide on how to achieve a certain A or B rating. It contains basic information for some of the most common components.

Rating (Wh/m2/Yr)	A1 (0-25)	A2 (25-50)	A3 (50-75)	B1 (75-100)	B2 (100-125)	B3 (125-150)
Solid Ground Floor U-Value (W/m2K) Insulation	0.12	0.12	0.16	0.20	0.20	0.22
Partial Fill Cavity Wall U-Value (W/m2K) Insulation	0.12	0.16	0.20	0.22	0.22	0.25
External Rendered Insulation System U-Value (W/m2K) Insulation	0.12	0.16	0.20	0.22	0.22	0.25
Timber Frame Construction U-Value (W/m2K) Insulation	0.12	0.16	0.20	0.22	0.22	0.25
Cold Pitched Roof U-Value (W/m2K) Insulation	0.12	0.12	0.14	0.16	0.16	0.16
Warm Pitched Roof U-Value (W/m2K) Insulation	0.12	0.12	0.14	0.16	0.16	0.16
Doors/Glazing U-Value	0.80	1.10	1.30	1.50	1.80	2.00
Electrical (Photovoltaic)	5m2	No	No	No	No	No
Electrical (Lighting)	100% CFL	100% CFL	100% CFL	100% CFL	100% CFL	100% CFL
Airtightness (m3/hr.m2)	2	2	2	2	2	2
Water Heating	4m2 Solar Panels	4m2 Solar Panels	4m2 Solar Panels	4m2 Solar Panels	By Mains Heating System	By Mains Heating System
Heating (Gas)	91	91	91	91	91	91
Ventilation	HRV-90%	HRV-85%	HRV-85%	Natural	Natural	Natural

Note: This information only serves as a guideline. They are indicative only and must not be taken as a final specification as the rating achieved will depend on numerous things such as the shape, size and orientation of the building along with other specifications not included above.

To satisfy BER requirements, to achieve an A1 rating, your home would have to conform to the specification set out in the rows listed under A1. For example, the insulation U-values need to be, at maximimum, 0.12 W/m2K in all areas of the home. You will need 4m2 solar panels and a boiler with an efficiency of over 91%. If any one component in the home does not conform, then you will receive a lower rating. The same principle applies for A2, A3, B1, etc.

Only use chart information for components you have. For example, if you have a cold pitched roof (insulation between joists), then you won’t have a warm pitched roof (insulation between rafters).

A Passive House is a building in which a comfortable interior climate can be maintained without active heating and cooling systems. The house heats and cools itself, hence "passive".

The prerequisite to this capability is an annual heating requirement that is less than 15 kWh/(m²a), not to be attained at the cost of an increase in use of energy for other purposes (e.g., electricity).

Depending on its size and complexity, a passive house project can take up to twice as long to plan as standard construction. Passive houses demand more from everyone participating in their planning and building, but are superior to, and more environmentally sustainable than, traditional buildings.

Following are the basic features that distinguish Passive House Construction:

Compact Form and Good Insulation	All components of the exterior shell of the house ae insulated to achieve a U-Factor that does not exceed 0.15 W/(m2k)
Southern Orientation and Shade Considerations	Passive use of solar energy is a significant factor in passive house design
Energy-efficient Window Glazing and Frames	Windows (Glazing and Frames, combined) should have U-Factors not exceeding 0.80 W/(m2K) with solar heat-gain coefficients around 50%
Building Envelope Air Tightness	Air Leakage through unsealed joints must be less than 0.6 imes the house volume per hour
Passive Pre-heating of Fresh Air	Fresh air may be brought into the house through underground ducts that exchange heat with the soil. This preheats fresh air to a temperature about 5°C (41°F), even on cold winter days.
Highly efficient Heat Recovery from exhaust air using an Air-to-Air Heat Exchanger	Most of the perceptible heat in the exhaust air is transfeed to the incoming fres air (heat recovery rate over 80%)
Hot water supply using Regenerative Energy sources	Solar Collectors or Heat Pumps provide energy or hot water
Energy Saving Household Appliances	Low energy refrigerators, stoves, freezers, washers, dryers, etc are indispensible in a passive house

The following steps should be taken when planning and constructing a Passive House.

1. Site Planning
2. Pre-Planning
3. Planning towards Passive House realisation
4. Planning: Building Elements
5. Planning: Ventilation
6. Designing Additional Building Technology
7. Construction Phase - Envelope
8. Construction Phase - Ventilation
9. Construction Phase - After Fixes, Additional Building Technology

• How suitable is the site for a passivehouse
• Does the site have access and utilities connections?
• Is planning permission for a passivehouse likely?
• Is a compact building shape possible? Terraced houses or larger blocks are an advantage.
• Is a southerly orientation (±30°) and large south-facing window areas possible?
• Consider shading factors preventing the use of solar gains - any trees with conservation orders?

• Dimension south-facing glazing for solar gains. Dimension east/north/west facing glazing for sufficient light, not larger than necessary.
• Minimise winter shading:
  • Garden Walls
  • vegetation
  • Balconies
  • Roof Overhangs
  • Outbuildings
• Simple envelope shape, if possible avoid steps in walls, dormer windows, etc. Clearly define the thermal (heated) envelope and the airtight layer.
• Floor plans:
  • Make installation zone(s) compact and concentrated, e.g. by placing bathrooms above or next to kitchens, etc.
  • Consider routing of, and space for, Ventilation Ducts.
• Contact local Planning Office to discuss initial ideas and site plan. Explain Passive House Ventilation Principles since these may not follow Local Regulations

• Plan Wall/Foundation/Roof Construction and Insulation thickness.
• Avoid cold bridges in the design - modify as required. Mitigate by minimising or optimising cold bridging if avoidance is impossible.
• Plan in enough space for building technology. Make sure there is space and access for regular maintenance.
• Floor plans:
  • Short Pipe lengths for cold, hot and waste water
  • short Ventilation Ducts - cold air ducts outside the heated envelope, warm ducts inside

• Ultra-insulated construction elements according to passivehouse rules, for external elements the rule is U ≤ 0.15 W/(m²K) - strive for 0.1 W/(m²K).
• Design connection details to eliminate cold bridging - if in doubt calculate and verify.
• Design connection details to assure airtightness.
• Optimise Glazing:
  • Type of Glazing
  • Frames/Casings
  • Glass Area
  • Sun Shading, etc.
  • Optimise Glazing:
• Calculate the specific space heating demand.

• Routing of Ventilation Ducts:
  • Keep cold ducts outside the heated envelope. If they need to be inside then only for very short lengths and highly insulated
  • keep warm ducts inside the heated envelope. If they need to be outside then only for very short lengths and highly insulated
  • Use short ducts with smooth walls
  • Keep flow velocities below 3 m/s throughout
  • Design measurement and flow balancing facilities into the system
  • Consider fire protection
  • Consider noise factors, including noise reduction.
• Air Inlets:
  • Avoid short-circuiting air flows
  • consider throw widths
  • Incorporate flow regulation/balancing possibilities.
• Air Exhausts:
  • Do not place above heating elements (if present).
• Dimension overflow openings for a pressure drop Δp ≤ 1 Pa.
• Central Ventilation/Heat Recovery Unit:
  Position Heat Exchangers close to or inside the Thermal Envelope. Good positions are inside the Heated Envelope or in a basement.
  The unit should meet or (preferably) exceed these data:
  • Overall efficiency ≥ 75%
  • Leakage to surrounding air < 3% of the rated flow volume
  • Internal Leakage (between intake and exhaust air flows) < 3% of the rated flow volume
  • High Electrical Efficiency, Power Consumption < 0.45 Wh/m³ air
  • Have suitable Regulation/Control Facilities
  • Have low Noise Rating
  • Have excellent Heat Insulation.
  Ventilation User Controls:
  • Settings: High, Normal, Low
  • Possibly time-limited booster functions in Kitchens, Toilets and Bathrooms.
  Kitchen Extractors connected to the ventilation system should have good extraction capabilities at a very low flow rate and be fitted with grease filters. However, it is preferable to use circulation only extractors with active coal and grease filters.

  Optionally, consider installing a Ground heat exchanger to keep intake air frost free. This can either be a ground-to-air exchanger or a ground-to-liquid exchanger with a liquid-to-air exchanger close to the ventilation unit. In some climates this will probably not be required. If required, consider:

  • Airtightness
  • Distance between cold channels and the building
  • Summer Bypass/Cooling Facilities
  • Extraction of condensate
  • Cleaning

• Sanitation, Hot Water:
  • Short pipes, very well insulated
  • Routed inside the Thermal Envelope.
• Sanitation, cold water:
  • short pipes, normal insulation.
• Insulate warm water and heating fittings.
• Use Water-Saving taps, etc.
• Connect washing machines and dish washers to the hot water supply.
• Waste water:
  • Short branch pipes, preferably a single (internal) discharge stack
  • Preferably, the stack should be ventilated into a roof void, otherwise through an insulated external pipe.
  • Sanitation and electrical/communications installations should preferably not penetrate the airtight layer but be cast into the foundation and sealed. In case the airtight layer has to be breached an efficient seal must be ensured (sleeves, tape, sealant).
  • Use Energy Efficient Appliances, the most modern models.

• Site management: Check that all materials supplied actually correspond to the materials specifications. Run a clean site with minimal waste.
• Freedom from cold bridges. On-site quality control.
• Integrity of the insulation. Unbroken insulation layers - no gaps in insulation materials.
• Airtightness: Check transitions, e.g. between walls and floors, seals where pipes, cables or flues are carried through the airtight layer and seams that form part of the airtight layer while still accessible.
• Airtightness: Carry out a pressure test as early in the construction phase as possible!
  • When? As soon as the airtight envelope is finished and while it is still accessible, i.e. before fixes (coordinate with relevant trades).
  • How? Air-tight test using a blower door or the ventilation system. All leaks must be located while the building is pressurised (smoke, handheld anemometer, if necessary, thermography).

• Airtightness. Check that piping and duct-work conserve the integrity of the airtight envelope.
  • Ducts: make sure they are clean and leak free
  • Central Ventilation Unit: check accessibility for filter change and noise reduction measures
  • Check Duct Insulation - is it present where required and correctly installed?
• Flow settings in normal operation:
• Measure Intake and Exhaust Air Flows - compare them to ensure they are balanced
• Compare fresh and stale air distribution
• Measure Electrical Power consumption

• Air-tightness: ensure that airtightness is preserved when installations are carried through the airtight layer. Consider wall constructions incorporating an internal installation void.
• Heat insulation of Pipes and Fixtures: check correctness and integrity