Whether you are constructing a new building, or looking to upgrade your existing home, there are significant economic and environmental savings achievable by going ‘green’.
It can save you money on your electricity and heating bills.
Your home will be more comfortable and convenient.
And you will also be making a vital contribution to reducing climate change.
Today’s world encourages us all to incorporate environmentally friendly products into our designs. At openplan.ie we aim to be environmentally responsible and inform clients of their options in terms of ‘greener’ solutions to all construction projects.
Interest in sustainable building methods has never been so high, particularly now that it is largely accepted that our activities are damaging the planet. The following information aims to provide tips on energy efficiency to those planning to build or renovate there existing home.
Modern development can better assimilate into the landscape by imitating the traditional settlement pattern. A well-chosen site, sheltered and screened is of fundamental importance.
The transmission of sunshine through windows which is known as passive solar heating can reduce heating costs. The selection of a site which is exposed to the low-altitude winter sun can allow for passive solar heating.
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.
Building Form & Orientation
The orientation of the room layout of your home is one of the key components with sustainable design. A dwelling 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.
Levels of insulation higher than those required in the Building Regulations are in many cases economically justified. Insulation should be well distributed around the building shell. It is better to have a good overall level of insulation than, for example, a highly insulated floor with no roof insulation.
Depending on your chosen building method, you can also install insulation that's not as damaging as fibreglass or some mineral wools. There is now a wide choice made from wool, natural fibres such as hemp, or cellulose from recycled newspapers. Many of these come in the form of blankets than can be cut to size or shape and slotted in, or in a semi-liquid form that's blown into the cavities.
Attention should be given to the avoidance of thermal bridges. These are areas within the construction where the insulation may have been left out, there are commonly located at lintels, jambs and sills of doors and windows, and at junctions where floors and ceilings meet external walls. They give rise to increased heat loss and possible condensation problems. To achieve the level of energy efficiency predicted by the design, it is very important to ensure good quality workmanship and supervision during construction.
Adequate ventilation is essential to provide fresh air and to remove moisture, odours and pollutants. However, excessive ventilation during the heating season results in energy wastage and can also cause discomfort due to draughts.
Controlled vents should be installed in every room; trickle or slot vents incorporated in window frames can ensure a reasonable amount of continuous fresh air and can be opened up or closed down to a minimum as required.
Attention should be given, during both design and construction, to ensuring that the building is well sealed. Services should be designed with minimum penetration of pipework and cabling through the building’s insulated shell. Doors and windows should come with factory-applied draught seals. Porches and draught lobbies can reduce draughts at external doors.
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.
You may also want to choose materials that do not use a lot of resources in their construction, as concrete blocks do. They are undoubtedly the cheapest, that's why they are so popular, but this, as with so many eco-choices, comes down to your choice of how far you are prepared to go.
Timber frame homes are a more acceptable option; they act as carbon dioxide stores and are renewable, as long as you ensure that the wood is obtained from a reputable source. Once concealed behind plasterboard and skim no-one would know it wasn't an ordinary brick-built home.
If there's a lot of glass in the building (a conservatory, for example) then double-glazing is a minimum; you may also consider special glass such as Low-E, which has a coating that reflects radiator heat back into the room while allowing the sun's heat through.
Heating & Energy Systems
Active solar heating systems, including a solar collector
on a south-facing roof, can contribute to heating needs.
A solar water heating system can provide about 60%
of a family’s annual hot water requirement, with back-up
heating coming from the conventional system. A solar space
heating system can contribute to heating needs, particularly
in spring and autumn.
Geothermal energy is renewable, environmentally friendly and cost effective. It is one of the most efficient ways to heat and provide hot water to a home.
To harness geothermal energy a heat pump must be installed. A heat pump taps into the underground heat source and converts it into a usable energy. Firstly, loops of pipe are buried in the ground vertically or horizontally. An antifreeze solution is continuously circulated through the pipe work absorbing heat from the earth. A heat pump transfers this energy for space and water heating.
They 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. The system does not require any external fuel and is designed to heat a whole building. The system uses a Heat Pump to move heat energy from one place to another, working just like a refrigerator.
Underfloor heating is another option worth considering. It's very difficult to install in an existing house but installation while building an extension is a lot easier and it can usually be added to the current central heating system. It is more expensive than installing extra radiators, but the water inside only needs to be heated to around 40-50 degrees, as opposed to the 85-90 of radiators, making running costs lower. In addition, you get even heat throughout the rooms, floors that are warm underfoot, and no radiators to get in the way around the walls.
Research and Choose
As has been touched on above, these choices are not easy to make. As well as the ecological pros and cons to be weighed up with many of the products available, there are also financial considerations to be made. The only way out is to research the options in each category, weigh up the pros and cons and assess the affordability of each one, before making your choice.