New Houses – overview
Under the latest changes to Part L1A it is very important to provide as much information to us before work starts on site (preferably as soon as Planning Permission is granted).
Quite simply, if work starts on site before the SAP Calculations are carried out, then the dwelling as it is being built may well fail either on the DER/TER calculations or the DFEE/TFEE calculations.
This may result in having a carry out expensive remedial work in order to achieve compliance.
Once the design and specification has been agreed, stick to it and do not deviate without contacting people like ourselves in order to change the calculations to see if it still complies with Building Regulations for Part L purposes.
Common changes that can make a new dwelling fail Building Regulations (Approved Document Part L1A)
- Fuel type – If the dwelling for example has been designed on mains gas and this gets changed to oil, then this have a huge negative impact on the SAP Calculations)
- Removal of renewable’s – People sometimes decide not to install renewable energy (more so now the Code for Sustainable Homes is being phased out), once again this can have a huge impact on achieving a pass.
- Change of materials – If things such as block types, levels of insulation are reduced, lesser standard of doors, windows and roof lights are used this will inevitably make the calculations worse.
- Junction design – As part of the SAP Calculations justification of junctions need to be provided. If the dwelling has been designed using manufacturers junctions/models and this is not undertaken then once again this has a large impact on compliance.
There are many different approaches to achieving a pass including building without the use of renewable energy as in Table 4 Approved Document l1A.
However this is more problematic than the table suggests, we will happily talk you though this.
There are many other factors involved, please contact us with any questions.
The Ideal Approach for new dwelling compliance under Approved Document l1A.
Please note that this is the Part L1A process and that a completion Certificate will only be produced once Building Control are satisfied with all aspects of the dwelling before signing it off.
Unfortunately the above process is not always followed, so if this is the case call us to discuss to make sure that the dwelling is still passing Part L1A requirements.
For further reading on SAP Calculations for new dwellings go to the following pages :-