I was speaking recently with someone who had engaged an "architect", (I say architect in inverted commas, I don't actually believe that the so called architect is actually an architect as defined in the Building Control Regulations) to design their house and get planning permission from them, which he truly did. They were asking me about how to achieve a good energy rating, for their dream house, which is fair enough as people are more energy conscious now days. When I asked did their "architect" not look at the matter when designing the house, the reply I received was "he specializes in planning only doesn’t get into the whole insulation thing".
It is my opinion (and one shared by many others I assume) that is it is no longer possible to get away with designing a house without looking at achieving compliance with Part L early on in the design stage. For me one has to design the house in tandem with using SEAI’s DEAP software, (or if a passive house, the PHPP software) which allows on check compliance with Part L and also establish the dwellings BER at the same time. Factors which influence compliance and are directly related to design include:
- Size and location of openings (windows & doors)
- Floor area
- Extent of perimeter of the building
The number of chimneys and even the provision of a draft lobby have an effect of the energy performance of a dwelling. For someone on a budget (everyone is now days) taking the above into consideration, at an early stage can help and potentially reduce the cost in ensuing compliance with Part L, down the road. Yes insulation is important; however it's not of much benefit in having a highly insulated south facing wall with few openings, with when the north facing wall is full of poorly insulated glazing! One might say the above is common sense, yet most of it is, but how many houses have been designed and built in the last 30-40 years and ignored common sense.
Of course other times also influence compliance like the type of heating, renewables etc, however whether using an oil fired boiler or a heat pump doesn’t generally have the same significant impact on planning permission, as the size of opening would.