Knowledge Base

SAP checklist

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At Base Energy, we pride ourselves in providing our clients with the most cost-effective solutions to pass their SAP scores- whilst keeping affordability front of mind.

If you are not familiar with SAP, it’s short for Standard Assessment Procedure and is the official methodology used by the government to asses the energy efficiency rating of a new build and existing residential buildings.

It is a mandatory requirement of Building Regulations Part L and used to create the energy performance certificate (EPC) which is needed to sell a property.

Without it, you won’t be able to achieve building regulations compliance and if you don’t have the right guidance and expertise from the start, it can become a costly and confusing process.

That’s why we have created our handy SAP Checklist which offers some helpful tips that will not only allow you to pass your SAP score but also present you with options and models that can help you to keep projects costs down.

Get it right from the start – when is the best time to get a SAP Calculation?

It goes without saying that the best time to carry out a SAP assessment is at the design stage of a project.

Don’t make the mistake of starting work on site until you have your SAP approved because if it doesn’t comply with Part L, any changes or renovations that are made to a property will prove costly and time consuming.

Think Fabric First 

There are a number of models you can use to pass your SAP calculation but the most cost-effective way is to start with your fabric U-values. Plus, there is also now a fabric compliance and if you pass this you should also pass for CO2 compliance.

First things first –  look at the improvements you can make to the building’s fabric efficiency before considering adding more expensive renewable bolt-ons.

Enhancements to the fabric could include increased insulation to the external walls, ground floor, roof and windows.

Lower the thermal mass

The thermal mass refers to a materials capacity to store and absorb heat.

By lowering the thermal mass by installing something like timber frame or lightweight block you can improve the energy performance of the building and boost the SAP score.

Heating controls

There are many new products and materials available now which can be included in a SAP calculation such as improved heating controls. For instance, you can consider installing Time and Temperature Zones, weather compensators, delayed start thermostats – all of which will help increase the SAP rating.

Let there be light 

A building should be designed so that it utilises all natural light sources in order to reduce its dependence on artificial lighting. The next stage is to look at the internal lighting source and ensure that this includes low energy fittings, LEDs and fluorescent tubes.  This is a cost-effective and quick way of improving a SAP score.

Heat Recovery 

The inclusion of heat recovery systems can significantly help to increase SAP. Popular options to consider are Flue Gas Heat Recovery and Ventilation with Heat Recovery.

Even more cost-effective, however, could be the addition of a Shower Waste Water Heat recovery unit. They are the relatively new kids on the block and work by extracting heat from shower waste water which is then used to preheat incoming mains water. They are around 70 percent efficient and are relatively cheap to buy and install so could be a very viable option.


The ventilation is a key part of the SAP calculation. This is also known as the air test, and the less air leakage there is the better the SAP calculation result. This can also be combined with mechanical ventilation with heat recovery (MVHR) for an even higher improvement. Concentrate on sealing up around skirting boards, soil pipes and risers.

Renewable or Low Carbon Tech

There are a range of renewable technologies – some which generate electricity (such as photovoltaic (PV) panels, wind turbines), some which generate heat (such as ground and air source heat pumps, solar hot water), and some which generate both electricity and heat (Combined Heat and Power).

All have different benefits in reducing CO2 emissions in a property and can provide a significant SAP boost. Renewable technologies do by their nature and tend to be more expensive and are not always needed to require a pass so always start with fabric first.

Choose the right partner 

At Base, we are here to guide you through the SAP process and offer a seamless transition to help you meet compliance as quickly and as easily as possible. Our national assessors have vast experience of completing SAP and SBEM calculations and as they are fully OCDEA accredited, they can also issue EPCs.

They will work with you to provide the most practical and cost-effective solutions to help you achieve a pass as well as offer guidance to help your development to go beyond building regulations.

This includes:

  • Design advice and recommendations
  • Liaise with local building control office,
  • Complete all parts of your SAP assessment
  • Guaranteed SAP design pass and fast turnaround


A little help from us 

To find out more or to discuss a SAP calculation, please call us on 020 3286 2016 or email info@baseenergy.

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