Over 2025 we built a three-storey extension on to the rear of our home. The build started in March 2025 and was structurally completed in October 2025. Through November and December 2025, we fitted out and decorated the new kitchen, utility, bathroom and ensuite bathroom.

This project describes the smart extension we have added to our existing home.

We moved into this newly built house in December 1995. The existing utility room was removed when the kitchen was redesigned back in April 2009. The 4m × 5.5m conservatory was added in March 2009.

This is what the rear of the house looked like in February 2025, with the conservatory removed to enable the builders to start work. The conservatory was 5.5m wide × 4.0m deep but, it was too cold in winter and too hot in the summer. Only the top left window in this photo remained but, we had that replaced to match the new windows.

The extension creates three new spaces on the ground floor. The first floor covers the footprint of the old conservatory but also extends along the whole of the back of the property.

1. A combined kitchen, dining room and lounge area (shown in red) encompassing the old kitchen and dining room. This will have 5.6m wide bi-fold doors exposed to our rear garden. The sun just about shines through these doors early in the morning and late in the evening during the summer.
2. A long narrow utility room (shown in blue). The existing back door remains in place and a new pocket door from the kitchen provides access into the utility room.
3. The existing lounge will no longer accessible via the arch from the old dining room, creating a separate space for relaxing or entertaining.

The extension solar is documented on another page.

The kitchen is the heart of the extension and utilises three distinct colours. The rear is a darker, anthracite colour with copper highlights. It features a (close to) white quartz resin worktop with lighter (off white) cabinets on the kitchen side and a light oak finish on the lounge side.

To the left of the kitchen door we have an integrated fridge/freezer, double oven with storage and a large larder cupboard. The pocket door on the left of this image is a glass panel door leading into the utility and to the back door.

To the right of the kitchen door we have more storage, with an integrated bar.

The new garden lounge and dining room has large bi-fold doors out into the garden. The whole space will have underfloor heating and air conditioning.

As part of the extension build, we are making some big changes to our heating and hot water system.

The original plan was to fit a 75" smart UHD/4K TV on the utility room wall with wall mounted KEF T-Series flat panel, T301 left & right speakers + T301c centre speaker.

Having marked up the TV dimensions on the wall, I decided to fit a 65" TV instead.

We plan to move our smart oil heater project into this office space, to avoid using the electric underfloor heating much of the time. This will be much more responsive to requests to change the temperature and as the project describes, it uses occupancy sensing to intelligently automate it.

The extension incorporates our old main bathroom and significantly extends it. The new 'bathroom' will have:

• A feature wall behind a free-standing bath.
• A large walk in shower (1.8m × 0.8m).
• A sink / cabinet unit with storage.
• An illuminated and heated mirror over the sink with shaver socket to one side and a wall mounted tooth brush charger.
• Toilet.
• A smart home controlled, tall open-ended radiator/towel rail with electric element and illuminated momentary switch to activate it for a set period of time (for use in the summer, when our central heating is off).

The bathroom will have its own slave processor to monitor and control most of the smart home features and will be part of my Home Control System. This includes intelligently controlled, dimmable lighting in the ceiling, inside the wall niches and under the cabinets.

The extension extends my our daughter's bedroom significantly and adds a new walk-in wardrobe and an ensuite bathroom which will have:

• A huge walk in shower (2.2m × 0.9m).
• A sink / cabinet unit with storage.
• An illuminated and heated mirror over the sink with shaver socket to one side and a wall mounted tooth brush charger.
• Toilet.
• A smart home controlled, tall open-ended radiator/towel rail with electric element and illuminated momentary switch to activate it for a set period of time (for use in the summer, when our central heating is off).

The master ensuite will have its own slave processor to monitor and control most of the smart home features and will be part of my Home Control System. This includes intelligently controlled, dimmable lighting in the ceiling, inside the wall niches and under the cabinets.

We plan to have three smart blinds over the 5-door bi-fold doors with a 1-2-2 configuration, the '1' being the main door to enter and exit the garden. These can be manually controlled by three MK Grid Plus K4900 switches mounted on a 6-gang switch plate (the lower three switches are used for other lighting) but, mostly they will be intelligently controlled by my Home Control System. They can also be voice controlled the lounge Amazon Echo.

Each smart blind will be controlled using a Shelly Plus 2PM and we have already extensively tested these. There is a web interface and an app to configure and control them directly.

Even with a 45mm deep back back box, there will not be enough room to comfortably mount the three modules behind the switch plate. To create more space I am using these over size, HGS68 boxes and only exposing the top half through the plaster board. These are 48mm deep × 134mm wide × 135mm high. The bottom half will have a cover fixed to it, which is hidden behind the plasterboard. This will provide plenty of space for the wiring and Shelly modules, which will even fit edge out.

Because we have a large flat floor area, we are installing a hidden docking station in the new lounge area for a robotic vaccum cleaner. This will be able to keep the whole open plan area clean.