I've been asked for a SAP Assessment - What's that?

You're at the beginning of planning your project and rightfully excited! Things begin to get real when you contact your local planning department and they give you a long list of things they need from you to approve your project, including.. a SAP Assessment! To those who know, it's part of the process. But what if this is your first time, what exactly is it? Let's see if I can explain it for you:

SAP stands for "Standard Assessment Procedure" and is a mathematical method developed for assessing the energy performance of a proposed development against the current Building Regulations. It takes into account the dimensions of the build, the proposed materials it is to be constructed from, the windows, the heating, ventilation and many other aspects such as renewable technologies. It runs all these details in a program that uses the mathematical method to compare against the minimum it should be achieving in terms of Building regulations.

The results of the calculation are represented as a DER "Dwelling Emission Rate", DFEE "Dwelling Fabric Energy Efficiency" and most recently DPER "Dwelling Primary Energy Rating".

DER - Dwelling Emission Rate is a measure of predicted carbon dioxide emissions in kg/m2

DFEE - Dwelling Fabric Energy Efficiency is a measure of how much energy is required to heat the house based on how well it is insulated, how good the windows and other glazing is. It does not include the heating systems or renewables.

DPER - Dwelling Primary Energy Rating gives a more rounded example of the performance of a property and includes fabric and heating and also the impact each method of fuel generation (cradle to grave) has. This Factor gives better results when high efficiency systems such as Heat Pumps are used and when renewables are employed to reduce energy demand.

So, once the calculation is completed, it will either pass or fail. If is passes - great! If not, as a consultant I will work with you to find a solution to improve the performance of the fabric, or look at better performing heating systems. We will then issue you a Building Regulations England Part L (BREL) Report, a SAP Worksheet with all the calculations within it, and an agreed Specification which lists the design stage details we have used to achieve this pass. It is incredibly important to let your consultant know if anything changes throughout the build as even seemingly minute changes can significantly affect the final results, perhaps even leading to a As Built Fail and costly remedial works (which we most definitely do not want to happen!)

As I tell all my clients, if in doubt - just give me a call! I am happy to explain any aspect of the process and care about helping you achieve your construction goals.