B.E.R Certification and Air Tightness testing

For all our new homes we provide a preliminary B.E.R cert. This provides an accurate guide as to the future energy performance of a home. The purpose of this preliminary cert is to highlight weaknesses or areas that can be improved before construction begins.

As per the building regulations a final cert is provided on handover of all completed homes.

Air tightness testing is carried out in conjunction with the BER cert and the final value is one of the inputs which effects the  B.E.R rating.

Since January 2009 it has been compulsory to produce a B.E.R cert for all new homes. The B.E.R cert is designed to provide homeowners with an indication of the energy performance of their home; however it takes no account of how a home is actually operated. Thus it is similar to the fuel consumption figures provided with a car, the figures are theoretical and take no account of driving style or usage patterns.

The B.E.R is calculated by:

  • Measuring the building, the size of windows and doors and their orientation, and how well each element is insulated
  • Examining how the house is ventilated, checking the levels of air tightness.
  • Looking at the space and hot water heating system, and how efficient these systems are and what contribution is made by renewables
  • Calculating the electricity demand from lighting, fans and any pumps fitted
  • The calculations are all based on a notional standard family with a standard pattern of occupancy.

The end result is a figure expressed in primary energy usage per metre square of floor area per year (kWh/m2/yr). Any result less than 75 gives you an A rating.

Where a house is still at planning stage, the most cost effective way to improve the rating is to focus on orientation, and in particular by attempting to maximise the solar gain. Any reductions in north facing glazing (and increases in south facing glazing) will have dramatic effects on the rating. Multiple open fires are also best avoided, where possible they should be elimanted or replaced with a wood burning stove.

We have generally found that homes with reasonable orientation and a stove fitted in place of an open fire built to our standard spec will achieve an A3 rating. To go beyond this without adding cost is difficult, the next step is to increase further the levels of insulation, and then to introduce mechanical heat recovery ventilation. This technology is relatively simple but for it to work well the house needs to be extremely air tight. As you go further up the scale, there is undoubtedly diminishing returns on investment, the improvements make less of an impact and become costly to implement.

Before commencing any new build we produce a preliminary B.E.R cert, and then work through the various options with the client. The challenge is to find the correct balance between initial build cost and long term running expenses.


McCarthy Quality Homes is focused on delivering a quality product, regardless of the scale of the project, or the level of expenditure involved.




McCarthy Quality Homes Ltd is a registered installer under the SEAI Home Energy Saving Scheme.  Read More

Home Bond Certificate

McCarthy Quality Homes is a registered contractor with Homebond. Read More

BER Certification

All McCarthy Quality Homes come with a BER certificate. Read More

Contact Us

Cian McCarthy

Address: Killowen, Nohoval, Co Cork
Tel: 087 2421490
Email: cmccarthy@mqh.ie
Website: www.mqh.ie