When a client or their designer submits drawings, plans and
specifications of the development to a SAP assessor, a desktop exercise is
carried out-using specialist software. We recommend that the SAP calculation is
undertaken early in the design process. This will prevent any re-designs, which
may be costly.
Usually, SAP calculations involve three main stages. This blog aims to explore each stage in-depth for anyone looking to understand the SAP calculation process further.
Read on to find out more.
As Designed Stage
During this stage, the accredited assessor prepares summary
information based on the suitably scaled and fully dimensioned plans and
drawings provided by the client/agent. This includes:
- The total floor area of the dwelling,
- The floor area of the warmer living area,
- The areas of the heat loss floors, walls and
roofs - Dimensions of external windows and doors; storey
heights, etc.
Using the specification provided, the assessor calculates
the performance of the thermal elements. These elements are expressed as ‘U’
values, which means the rate at which heat passes through the fabric of the
building.
This data is then input into the SAP calculation software.
Data entered is related to:
- Type of dwelling
- Floors
- Walls
- Roofs
- Openings (windows, doors, roof lights)
- Ventilation
- Main and secondary space heating
- Hot water generation
- Renewable technologies, including photovoltaic panels and solar water heating
- Energy-efficient lighting
The SAP software determines whether the proposed dwelling
will comply with the requirements of the Building Regulations, with regards to
the conservation of fuel and power.
The software has the ability to model different variations
of the design if the initial specification design doesn’t show compliance. The
SAP assessor can then advise the designer of the shortfalls and recommend
appropriate solutions.
From this the assessor produces reports that the client or
designer need to submit to Building Control. This will include a Predicted
Energy Assessment (this provides a rating of energy performance based upon the
specified design and is required to market the property).
2. Build stage
Considering that any changes on site can have a huge impact
on the SAP, we suggest that these are checked prior to any changes.
At Built Stage, the assessor will edit the SAP calculation
to reflect the results of the air pressure test and any variators to the
specification. The software is then used to check that the completed dwelling
still meets the
requirements of the Building Regulations. If it doesn’t meet those requirements, we would recommend
remedial action.
For new builds, we would check to ensure that the dwelling
is registered on the Government’s central database of national property address. If this is not
the case, we would arrange for the address record to be created.
3. As Built Stage
Upon project completion, we finalise the SAP calculation and
create an Energy Performance Certificate.
In general, SAP calculations are based on a desktop exercise
and not a site survey, highlighting the importance of correct information being
submitted at the earliest possible stage.
Here is a minimum suggested list of the information sources
and data items required:
- Site address and postcode
- Site plan to include orientation of the
dwelling(s) - Plans of each storey
- Elevations drawings for each elevation to a
recognised scale - Sectional drawings of the dwelling
- A written specification
Conclusion
If you would like to find out more about our SAP calculation services or would like to speak to one of our team members about energy advice for your property, get in touch on 01372 438 039 or fill out the form below and we’d be more than happy to help.
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About Us
We are a friendly team of Engineers delivering Sustainability and Building Compliance Solutions for developments in the Commercial and Residential sectors, which include Energy Statements, Noise Impact and Vibration Assessments, BREEAM Assessments, and Air Quality Assessments in the Environmental, Social and Governance sectors.
Contact us at:
Sustain Quality Ltd
PO Box 393
COBHAM
KT11 3EL
info@sustainquality.co.uk
01372 438039