The Grant House

A home transformed

In 2020, a large renovation project commenced at a family home in Chippenham, Wiltshire. The semi-detached property, which initially had three bedrooms, underwent a large extension and much of the interior was also updated, transforming the house into the dream four-bedroom home that the homeowners wanted. A core part of this project, included the removal of the old heating system and upgrading it to a greener, more efficient alternative.

A new air source heat pump replaced the gas boiler that was previously heating the property and all the old radiators were also removed, being replaced by a combination of underfloor heating and aluminium radiators. The complete heating system was supplied by Grant UK who followed the installation from start to finish. Working closely with the homeowners and their installer, Grant UK also provided onsite technical support and system design assistance.

This Vlog takes a closer look at this whole house renewable heating project, interviewing the homeowners, the installer and one of Grant UK’s in-house Senior Field Service Engineers who worked together to make this Wiltshire family home more sustainable.

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Meet the Family

Helen and Oli Selman purchased their home in 2015.

Having lived in the property for several years, Helen and Oli embarked on the ambitious renovation project to turn the house they loved into the forever home they wished for to be enjoyed by them and their two children for many years to come.

Helen and Oli wanted the renovation to not only deliver their forever home but to enable them as a family to live as sustainably as they could. To achieve this, they needed to improve the efficiency of their heating and change the heat source to a greener alternative so they turned to Grant for their whole house renewable heating system.

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The renovation project gave us the opportunity to completely transform our heating system, moving away from a fossil fuel and going green with a new heat pump

Helen & Oli Selman, Homeowners

Meet the Installer

The installer who undertook the fitting of this new central heating system was Jake Meadows of Meadows Plumbing & Heating.

Based in Chippenham and providing heating and plumbing services to the local area, Meadows Plumbing & Heating are members of Grant UK’s G1 Installer Scheme. Jake and his team cover all aspects of plumbing and heating including traditional fuel heating systems and renewable technologies.

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I have fitted a lot of Grant products over the years and my experience with the Company has always been very positive. They supply really good products and the support is excellent too, from sales through to technical. We have worked closely with our local Grant UK Sales Representative, Chris Price, on a lot of our projects including underfloor heating installations, oil boiler installations and more recently with our renewable jobs

Jake Meadows, Installer

The Products

To fulfil the heating and hot water requirements for Helen and Oli’s larger home, a new heat source was installed alongside a new hot water storage cylinder, with underfloor heating systems laid throughout the downstairs of the property and aluminium radiators installed upstairs. Click on the technologies to find out further information and see where they are located in the house.


The heat loss calculation identified the Aerona³ 13kW R32 air source heat pump as the appropriate sized heat pump to suit the property. This twin fan heat pump has a compact footprint and is Quiet Marked approved, two factors that were important in this installation – Helen and Oli did not want their heat pump to impact the surrounds of their garden, both in stature and low noise levels. All of Grant’s heat pumps boast A+++ ErP ratings reflecting their excellent efficiencies. The range is also installer friendly with the units designed to make installation, servicing and maintenance straightforward for heating engineers.

Grant Aerona³ R32 Air Source Heat Pump Range
01 Anti-vibration feet are put into position on a flat level base- in this case a new patio.jpg 02 Jake & Matt bolt the heat pump to feet.jpg 09 John runs through the heat pump perameters  on the controller with Jake.jpg Comprehensive handover with the homeowner is provided to ensure they fully understand the system.jpg The Grant House.jpg


To efficiently store the system’s hot water, a Grant MonoWave High Performance 300ltr Cylinder was also installed. These cylinder models are specifically designed to complement heat pumps, partnering together successfully to increase the overall efficiency of the system. Featuring a large primary coil, the cylinder can effectively transfer the heat from the system into the water, aiding the heat pump’s operation and ensuring that the family’s hot water requirements are always fulfilled.

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It is well recognised that underfloor heating systems work very successfully with a low temperature system like an air source heat pump. For Helen and Oli’s home, two types of underfloor heating systems were fitted. For the floor area within the new extension, a Grant Uflex underfloor heating system was installed which is embedded within the floor construction. Grant Uflex is ideally suited to new builds and extensions because the pipe can be laid and screed poured during the early phases of a project, allowing other works to be completed while the screed fully dries. The 16mm Uflex pipe was laid in a meander configuration to enable even coverage and heat emission emitting into the living space. It took Jake and Matt one day to lay the pipework and after pouring the screed, this was left for 30 days to allow the system to dry.

Uflex Underfloor Heating
05 The pipe is laid in a meander configuration with the flow heading towards the coldest areas first.JPG 07 Matt connects the pipe loops to the Manifold. Actuator wiring is connected to system controller.JPG 08 After filling and pressure testing the pipe loops, a dry screed is delivered and poured on top of the Uflex pipes.JPG 09 The screed is flattened to a 65mm thickness and then left to dry for around two months before it can be tiled.JPG The Selman's finished kitchen with UFLEX underfloor heating.jpg


Throughout the remainder of the downstairs, where existing flooring was in place, Grant’s low profile underflooring heating system – Uflex MINI – was installed. Consisting of self-adhesive panels featuring castellations, the Uflex MINI system is just 15mm in finished floor height which made it ideal for installation on Helen and Oli’s existing, level floors. After positioning the panels, the 9mm Uflex MINI pipe was simply clipped into place and a self-levelling screed poured on top. Due to the incredibly low profile, less screed was needed with the Uflex MINI system compared to Uflex, and the drying time was also significantly less – within three days, the Uflex MINI system was being walked on, reducing disruption, and allowing the other stages of the project to continue.

Uflex MINI Underfloor Heating
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Upstairs, new Afinia aluminium radiators were installed in all the bedrooms and landing space. For this installation, horizontal Afinia models were fitted, ranging in size from 4 sections to 8 sections in length. The excellent thermal conductivity of Afinia radiators allows them to warm up quickly and respond rapidly to any changes that the family make to the heating demand. Their white coated finish, curved edges and sleek design make the Afinia radiators a stylish addition to all of the rooms while also effectively emitting warmth into the space. It is important to note that radiators on a heat pump system are cooler to the touch compared to those working with oil or gas boilers – this is because the heat pump operates a low temperature system but with correctly sized radiators, the property’s heating requirements and comfort levels will be achieved.

Afinia Aluminium Radiators
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Renewable Heat

To support homeowners with the transition of heating their home with renewable energy, the Government’s Domestic Renewable Heat Incentive Scheme issued eligible installations with quarterly payments over seven years. Through the RHI, householders could earn a financial return on their renewable heating system and this was something that Helen and Oli wanted to benefit from.
In order to apply for the RHI, the installation had to meet the Scheme’s criteria which included selecting an eligible renewable heating system which had to be commissioned and certified by a MCS accredited installer. By choosing a Grant heat pump, which is MCS certified, Helen and Oli were able to apply for the RHI Scheme payments for their new heating system. 
[The Domestic RHI Scheme closed to new applications in March 2022 but please click here to read more about other Government incentives and support.]

The Benefits

After nearly a year, Helen and Oli completed their home extension and renovation, transforming their property throughout. Their home is now also being kept sustainably warm, with significantly lower emissions, a much reduced carbon footprint and lower fuel bills. They have already received their first RHI payment, a financial reward for their green decision that they will continue to receive for the next seven years. The family has adjusted to the differences between their old gas central heating system and their new heat pump system, and they are enjoying the comfort that renewable heating brings.

Building the extension, updating the heating system and completing the interior changes to home has been a labour of love. When we bought this property, we knew we would not want to move again so the time and effort put into this house over the past two years has made the property into the home our family will live in for years and years to come

Helen & Oli Selman, Homeowners

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