Whole Building Heat Loss Calculation

SmartHTC is a unique algorithm that can calculate an accurate and reliable measurement of whole building fabric heat loss (also known as a Heat Transfer Coefficient or HTC). Whereas SAP and EPC assessments make assumptions about the building, SmartHTC uses actual temperature and energy data from the property to derive an energy performance rating.

SmartHTC on an In Home Display with temperature sensors

SmartHTC heat loss algorithm

Access to the SmartHTC web interface and API for calculating whole fabric heat loss (HTC). Can be integrated into your own products or used independently using our online interface.

What's included

  • Web-based interface

  • API integration

  • Unlimited calculations per property

  • 12 months access

Price from

£10 GBP

per property

Excluding VAT

Energy efficiency ratings made accurate.

The thermal performance test enables an accurate measurement of whole fabric heat loss (known as Heat Transfer Coefficient or HTC). This can be used to provide a rating on a home's energy efficiency.

  • Surveyor talking to homeowner

    Replaces inaccurate predictions

    The thermal performance test uses real measurements of internal temperature and energy consumption. Readings can come from existing smart home systems or from discreet sensors placed around the house.

  • SmartHTC rating on a phone

    Use in occupied homes

    A test takes 3 weeks to complete and allows the house to be occupied throughout the measurement period. At the end of the test, the true performance of the building is calculated through our online portal.

Compatible with sensors and smart technologies from:

Complete building performance evaluation solution

The energy performance test and rating gives an indication of the true performance of the building that can be directly compared with the predicted performance.

Easy to use browser interface

Once measurements have been taken, all data is uploaded to a web-based portal where you will get the result.

Cost comparable to EPCs

At volume, the wholesale cost is comparable to an EPC lodgement cost.

Accounts for weather and occupancy

External weather and occupancy data are used to improve the accuracy of the result.

3rd-party tested and validated

The SmartHTC technology that powers the test has been developed over 10 years and rigorously validated by industry experts.

Thermal performance and net-zero targets

With such a high focus on the drive to carbon-neutral combined with the sheer numbers of properties in need of energy efficiency improvements, the need to accurately measure the true thermal performance of houses prior to retrofitting has never been greater. Every home is different, potentially even to an identical house next door, so it's extremely difficult to assess how best to prioritise retrofit spending and prioritise the program of works.

At the moment any assessment to define the Heat Transfer Coefficient (the term for the actual thermal performance of a property) involves expensive and invasive testing which require the property to be vacated for a period of time (potentially several weeks) to allow the property to be fully wired up to the sensors needed to check measured heat loss through floors, windows, walls, roofs and other elements.

As a result, these "co-heating" tests are simply not practical and rarely utilised outside of the academic world. Any knowledge of the actual thermal performance of a property is currently based on estimates using broad assumptions from visual inspections and SAP predictions. Such assumptions may not deliver the accuracy required to effectively retrofit large numbers of buildings.

Why use SmartHTC?

Existing assessments, such as Energy Performance Certificates, rely on visual inspections alone, yet many important factors such as insulation and airtightness cannot easily be seen. Our thermal performance test measures the real-world energy use of the building whilst it is in use.

Measure baseline performance

A single test provides a baseline measurement of how a house is performing prior to carrying out improvement works.

Identify upgrade opportunities

The test can be used to identify inefficient houses where further energy-saving upgrades may be required.

Quality assurance

The energy rating and result can provide quality assurance that an energy-saving upgrade is performing as expected.

Reduce energy bills

The energy usage breakdown may give insights into where the homeowner can save on their energy bills.

Who is SmartHTC designed for?

SmartHTC is designed for any organisation which needs to know the true thermal performance of their housing stock, assets or customers' homes.

Frequently Asked Questions

What can SmartHTC be used for?
SmartHTC results include a Heat Transfer Coefficient (HTC) and Heat Loss Parameter (HLP). Both are building performance metrics that provide an accurate insight into a building's true performance and can be used to compare buildings or measure performance improvements from retrofit works.
What is a HTC?
HTC stands for Heat Transfer Coefficient and is a measure of thermal performance or whole building heat loss. It accounts for heat escaping through walls, floors, ceilings and windows as well as infiltration and ventilation losses. It describes the rate of heat transfer from a building per degree of temperature difference between inside and out.
How is it different to a SAP Assessment?
A Standard Assessment Procedure (SAP) assessment is a methodology that calculates the HTC using assumed heat loss and ventilation rates based on the construction and features of the building. SmartHTC is unique in that it uses real measurements of temperature and energy data over a minimum 3-week measurement period.
How do I connect to SmartHTC?
The SmartHTC software can be accessed via a web-based user interface or programmatically using an API. The API accepts data via JSON format so is compatible with all programming languages.