SAP CALCULATIONS... PREDICTIVE ENERGY ASSESSMENTS... ENERGY PERFORMANCE CERTIFICATES... U-VALUE CALCULATIONS... NON-DOMESTIC ENERGY ASSESSMENTS... THERMAL BRIDGING CALCULATIONS... CODE FOR SUSTAINABLE HOMES... DAYLIGHTING CALCULATIONS... FEASIBILITY STUDIES... HOME USER GUIDES... SUSTAINABILITY STRATEGY STUDIES... LIFETIME HOMES ASSESSMENTS... ECOHOMES ASSESSMENTS... AIR TESTING... SOUND TESTING...

Analysing thermal properties is one of the key skills of a SAP Assessor.

The construction details of all building elements that represent the planes where the internal heated space meets the external unheated space are taken into consideration and the thermal properties of each individual part of each one of those elements is factored into the equation. This includes criteria such as whether the property is detached, mid-terrace, or semi detached; whether a flat has a flat or garage below it, etc.

By this means a U-value, representing the ability of the constructed element to withstand the passage of heat/energy, is calculated. Other factors are obviously taken into consideration, such as condensation risk analysis and Robust Standard Details (a standard for ensuring acoustic requirements are met). There is no point constructing any element to a building to a high thermal performance if condensation is going to occur or the acoustic requirements are not met.

Improved performance of insulating materials within the main build elements (ground floor, roof, and external walls) can have a large effect on the overall performance of a dwelling. Significant SAP calculation gains can be made by improving these main building elements for the simple reason that they comprise the planes of the building between the inner heated space and the unheated space beyond.  They also have a major cooling effect in warm weather.

The thermal properties of the individual part of each building fabric element is factored into the equation by the creation of a-u-value for each constructed element (ie, floor, external wall, separating wall, roof, floor over garage).  The Energy Assessor will need to know the exact specifications for each wall type, ceiling type and floor type being used in the construction.  The information is required at a detailed level; for instance, for a single wall type the exact type of blocks used, the size of air layer, the type of insulation used in the air layer, the inner wall block type, the plasterboard thickness, etc, will be required.  By this means a u-value, representing the ability of the constructed element to withstand the passage of heat/energy, is calculated.

Other factors are taken into consideration, such as the requirement for Sound Insulation and, on the negative side, Condensation Risk Analysis.  There is no point constructing any single element to such a high thermal performance that condensation is going to occur, or that despite an excellent thermal value, the acoustic requirements are not met.

The various possible insulation products for each element are entered into the equasion, building a mathematical model of the ground floor, external walls and roof. Into this model the windows and external doors, each with their specific u-values, are then factored, as are also the space heating and water heating, and ventilation systems to give the final result – a prediction of the performance of that dwelling.

• Thermal Properties
• Thermal Mass
• Thermal Bridging
• Cylinders & Measured Heat Loss
• Dimensions
• Boilers & SEDBUK (Seasonal Efficiency Database of Boilers in the UK)
• Ventilation Systems & the Appendix Q database
• Solar Gains
• Insulation
• Space Heating Systems
• Water Heating Systems
• Low Carbon Power Souces
• Condensation & Dewpoint Analysis
• Heat Pumps