An Teach Glas


High Performance Zero Carbon Passive House

Ecological Features

The Key Ecological Features of the design are;

  1. The use of vegetation and landscaping to protect the house against dominant prevailing winds. The house is located so that the outdoor living areas are on the sunny south side of the house.
  2. Existing trees and hedgerows will be preserved and additional planting will take place to provide natural habitat for native birds.
  3. The house is designed to increase solar gains therefore minimising energy used for heating. Warmer habitable rooms are on the south side while cooler service rooms on the north side. Glazing on the south facade has been maximised to increase solar gains while windows are limited to the north to reduce heat loss.
  4. Grass sod roof. Advantages: Creates a new habitat for plants and insects. Does not create an impermeable surfaces that has to be drained. They have the capacity to retain and absorb rain water therefore stabilising the flow of water discharged. Grass and soil do not require manufacturing therefore do not produce waste during production and do not diminish mineral resources, unlike concrete or metal that depletes natural resources and generate tons of carbon in their production. In addition planted roofs will neutralise a large quantity of carbon over its working like, making for a more sustainable future.
  5. Salvaged natural slate roofs. The area of roof that have traditional slate will be covered in salvaged slate. This is even better then using recycled materials, because the slates can be reused without the need for any processing, thereby reducing the embodied energy.
  6. Photovoltaic Solar Panels in additional to Solar Thermal Panels will cover the south sloping roof. The Photovoltaic panels will produce electricity that can be used in the house and exported to the grid thereby displacing energy created by fossil fuels. The PV panels will also act as the roof finish, thereby eliminating the need for additional roofing material and the associated embodied energy.
  7. Walls will be constructed using timber frame construction. Timber being a renewable material, unlike concrete, does not require large amounts of carbon gasses and when timber is put into a building carbon is essentially taken out of the atmosphere and locked away. Plus timber frame construction allows higher levels of insulation to be installed, further reducing energy consumption.
  8. Where a masonry finish is used, recycled natural stone has been selected. Natural stone has the advantage that it does not require manufacturing (which produces carbon) and it can be sourced locally. Also the advantage of using recycled stone means that the walls will have a natural weathered look rather than looking fresh out of the quarry.
  9. Superior levels of insulation will be installed. Insulation is the simplest form of energy reduction and environmental protection in the house. As the largest amount of energy consumed in a standard houses is for space heating, by reducing this need you are making simple energy savings. And the greatest benefit of insulation is that once it is installed it costs nothing to run, unlike other heating systems.
  10. All details are designed to almost eliminate all cold bridging. High levels of insulation are well and good, but you still need a structure to the house, and this can lead to cold bridging at edges and through the structure itself. Once this problem is recognised an experienced architect can detail the structure to reduce all this cold bridging, therefore increasing the overall insulation of the house and reducing energy costs.
  11. High performance glazing. Windows are always an area of higher heat loss due to their relative low insulation quality, but glazing technology is currently undergoing a revolution and even higher standards of heat retention are achievable. A U-Value of 1.1 w/sqmk is readily available and with U-Values of 0.6 w/sqmk entering the market, heat loss through windows can be controlled. For this project a minimum U-Value of 0.6 w/sqmk will be used.
  12. Timber Window Frames. Timber is a renewable material, unlike aluminum or PVC which depletes mineral resources, creates excessive waste and produce harmful dioxins. It also has a better insulation value.
  13. Many timber frame houses are clad in a layer of blocks which counteracts many of the environmental benefits of timber frame construction (because huge amounts of carbon dioxide are produced in the manufacture of cement). This project is clad in a rendered timber fibreboard system. Growing timber helps absorb carbon gasses and when timber is put into a building carbon is essentially taken out of the atmosphere and locked away.
  14. The use of environmentally friendly cement. Even though this is a timber frame house, concrete is still necessary for the foundations and floor slab but unfortunately most concrete is made using Portland cement which consumes huge amounts of energy to manufacture. Luckily an Ecocem product is now available in Ireland which is produced from a waste product of the steel industry, GGBS. This hugely reduces the carbon footprint created with the use of concrete.
  15. Use cellulose recycled newspaper insulation. It doesn’t have the high levels of embodied energy (energy required to manufacture and therefore the quantity of carbon created during production) associated with chemical insulation’s plus it reuses a waste product. Now it is being manufactured in Ireland, further reducing energy consumed for transportation and reducing the amount of waste produced in Ireland. Also, because it is installed through a system of pumping, it means cold gaps in the construction are simply eliminated.
  16. There is no point in insulating a house unless it is draft proof.And we don’t just mean the doors and windows because a surprising amount of air escapes through the construction and fixtures. This warm air has consumed energy to heat, and it is just being let escape. The solution is to provide an airtight vapour barrier outside a service cavity. This insures that the electrical and plumbing services do not puncture  the air tight seal and has the added advantage of providing higher insulation levels.  A further benefit is that moisture is blocked from entering the structure, eliminating potential rot and mildew.
  17. Even a super insulated house has to be ventilated to ensure good indoor air quality. But ventilation means heat loss, doing away with the benefits of additional insulation. This does not have to be the case, because by installing a ventilation heat recovery unit, the air that is entering the building is heated by the air exiting the building. This makes huge energy savings and ensures an even higher standard of air quality than conventional means of ventilation, and Energy Savings = Environmental Benefits.
  18. Flat plate solar thermal water heaters. They will meet a large amount of the houses hot water need substantially reducing fossil fuel consumed. Even in winter the panels are effective by increasing the temperature of water, which decreases the energy used to heat the water. The panels are integrated into the roof, to further increase their efficiency and make use of them as a cladding material, reducing the amount of material needed.
  19. The  small amount of supplementary heat that is needed for space heating and hot water will be provided by a combi pellet/log range cooker. Timber and pellets are sources of renewable energy. Timber can be sourced locally and wood pellets are manufactured in Ireland. Wood is a renewable source and is carbon neutral i.e. the carbon produced when burning the wood is absorbed durning the growth of the trees.
  20. Permeable external pavements, driveways and paths. Creating large areas of sealed parking and paving causes even more rain water to be directed into a treatment system or a drainage system. This deprives the soil of ground water, causes more flooding and places a higher demand on drainage systems. This does not need to be the case, by the simple use of permeable surfaces, such as gravel and specially designed paving, rainwater is allowed to percolate into the ground.
  21. There will not be a concrete path running around the whole building which would isolate it from the site and surrounding landscape. Instead plants and the lawn will grow beside the wall of the house.
  22. A wood burning stove will provide space heating. Wood is a renewable source and is carbon neutral i.e. the carbon produced when burning the wood is absorbed during the growth of the trees.
  23. Connect to a renewable energy electricity provider. This ensures that all electricity is produced by renewable sources, mainly wind power.
  24. All appliances and installations will have low energy ratings. Fridge, freezer, washing machine, dishwasher, oven, hob etc.
  25. Only biodegradable soaps and detergents will be used. This reduces the load on the wastewater treatment system making them more effective. This also reduces heavy metals building up in the soil or water table.

* Thanks to Miles Sampson Architects for compiling all of the above information.

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