What we do and what do you get for your money?


ADL1a – SAP Calculations – New Dwellings


SAP is the governments Standard Assessment Procedure for new dwellings (NEW BUILD and CONVERSION); each new property must be assessed using this method.


  • We calculate the SAP and advise you on how to achieve a pass under Building Regulations
  • We provide the U Values at no extra charge
  • We work out the individual Kappa values (Thermal Mass) instead of using the more onerous default figures
  • We calculate each linear loss (Construction Details) depending on your individual construction method; this again is to avoid penalising default values.
  • We will advise on specification and where possible find the most cost effective solution for your build
  • No Printed Drawings – No Problem; just send us a .pdf file printed to scale. This Service is chargeable with rates dependant on amount of drawings received
  • Upon completion of the dwelling and subsequent air pressure test we can supply you with the AS BUILT SAP Calculations and the all-important Energy Performance Certificate. This Service is chargeable at £30.00 + VAT per single plot – Discounts available for multiple plots


ADL1b – SAP Calculations – Overglazed Extensions

In Building regulations home extensions are approved under Approved Document L1b, if they are built within certain U-Value Parameters and the Glazing Area does not exceed 25% of the New Floor Area. If your requirements are outside of these constraints we can help prove that the extension built as you would like is better than the requirements of the Regulations.


  • There are 3 methods of compliance; (1) proving the 25% rule, (2) Area Weighted Calculation and (3) Full Comparison Calculation – each have a different price – we will only ever charge you the minimum required.
  • We calculate the SAP and advise you on how to achieve a pass under Building Regulations
  • We provide the U Values at no extra charge

Part G – Internal Water Consumption Calculations

  • We can supply you with a basic specification at design stage to give you targets when purchasing the internal water fittings (Flow restrictors for Taps and Showers, Bath size to overflow and Dual flush rates for toilets).
  • When Built we can supply the Final Certificate for your BCO and get this element signed off quickly
  • This Service is chargeable at £25.00 + VAT per plot – Discounts available for multiple plots.


Part F – Ventilation Calculations

  • We can advise on and produce calculations to aid compliance with Approved Document F of the current Building Regulations.
  • Each room will be calculated individually with calculations to show minimum levels of trickle ventilation and purge ventilation required to pass Building Regulations
  • If Part F Calculations are carried out whilst the SAP calculations are in progress then a standard charge of £75.00 + Vat per plot (or house type)will be applied; if SAP calculations have finished and we need to revisit the dwelling then a charge of £100.00 + VAT per plot (or house type) will be applied.