The following building regulations considerations apply when designing a multi unit apartment scheme. Grant may also be claimed for smaller developments which significantly reduce energy usage over normal building regulations requirements.

Building Regulations

Part L of the Building Regulations relating to the conservation of fuel and energy was updated on the 1st July 2008. There is now a requirement for renewable energy to be incorporated into the dwelling.

Part L Conservation of Fuel and Energy

A minimum of 10kWh/m2/yr of renewable energy needs to be installed on all new dwellings on which works commenced on or after 30th June 2008, certain arrangements are in place for works substantially completed by 30th June 2009. There are many technologies which can be used to comply with the regulations, wood pellets, wood gasification, heat pump and solar.

Solar is the most popular choice as it is relatively inexpensive to install on a new build and has very low maintenance associated with the installation. Please see the relevant pages on biomass and solar for further discussion regarding these technologies.

In order to demonstrate that the building complies with the regulations, the official SEI DEAP software must be used, the updated version of the software, DEAP III will clearly show if the heating system chosen will provide compliance for the development. As the renewable requirement is based on floor area, a detailed analysis of the renewable requirements is needed for large multi unit developments.

Using solar panels with good performance data will mean that compliance with the regulations can be achieved using less collector area, thus reducing the over all cost of the system. RVR can provide assistance to professionals when carrying out these calculations to ensure compiance with the above regulations. RVR can also provide technical support through all stages of a project from design to comissioning.

BER Chart

The figures needed when carrying out a DEAP assessment of solar collectors are as follows:

η0: Optical efficiency: This indicates the percentage of the solar rays penetrating the glass of the collector and being collected.

A1 and A2: The coefficients a1 and a2 describe the heat loss of the collector. They indicate the amount of heat that the collector loses to the atmosphere per m2 of aperture

Aperture Area: The area of the panel which collects energy

It is still difficult to determine the output of a collector just by looking at the figures alone:

A collector can have a high η0 which means it collects a lot of energy. But it can also have a high a1/a2 which means it doesn't retain the energy well. A collector can have a low η0 which means it does not collect much energy. But it can also have a low a1/a2 which means it retains most of the energy it collects.

A collector can sometimes compensate for poor efficiency figures by having a larger aperture area. Alternatively a collector with a small aperture area can sometimes have excellent efficiency figures and give a better output. This is important to note when designing a system, especially when roof space and/or finances are limited.

Grant Considerations

The Low Carbon Homes Programme

The grant currently available to developers is the Low Carbon Homes programme. This is the successor to the successful House of Tomorrow Programme. The programme is primarily for developments of 5 to 15 houses, but will also be considered for one off demonstration projects. It aims to significantly reduce energy usage and associated CO2 emissions. The programme will explore the technical solutions that have the potential to reduce CO2 emissions from energy use in a typical new home by at least 70% relative to a “reference dwelling” built to baseline Building Regulations 2005 standards.

Programme Details: The new programme will support and promote low energy consumption and low carbon dioxide emissions in new dwellings. There are a number of basic requirements. The dwellings must reach the following targets:

• A building energy rating (BER) of A2 or better
• Achieve an energy performance coefficient (EPC) less than 0.25 (well below the current Building Reg.s figure of 0.6)
• Achieve a carbon dioxide performance coefficient (CPC) less than 0.30 (well below the current Building Reg.s figure of 0.69)
• Generate electricity onsite (for supply or export) per unit to the equivalent of 10 kWh/m2/yr (primary) or greater.

Please click on this link to read further information on the low carbon homes programme http://www.sei.ie/Grants/Low_Carbon_Homes_Programme/