This project describes the extension we are adding 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.

The proposed 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 garden lounge area (shown in red) and also encompassing the old kitchen and dining room. This will have 5.5m wide bi-fold doors along length exposed to our rear garden. The sun will shine 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 will remain and a new door from the kitchen will enable 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 entertaining.

We plan to use kitchen cabinets and drawer fronts with integrated handles at the top and no handles mounted to the fronts.

We are adding an air condition unit like this Fujitsu AOYG18KBTA2 system, to provide independent cooling over the summer in the open plan space and the new master bedroom above it. In operation this will use less than 2kW and typically much less in operation.

The main ambient lighting will be split into four zones/groups with dimmable ceiling mounted down-lighters. There will also be some feature task lighting over the kitchen worktop:

1. Kitchen Lights - Ceiling mounted lights (orange)
2. Kitchen Worktop Lights - Hanging feature lights over the worktop (yellow)
3. Breakfast Room - The space next to the breakfast bar (blue)
4. Dining Room - Ceiling mounted lights over the dining area (purple)
5. Lounge - Ceiling mounted lights over the main lounge area (green)

The technology behind these is described in this project/review. We have given each group of lights a name that is used by our Home Control System and also by Alexa. This is to enable fully configurable, flexible or intelligent control via my smart home, voice control or physical switches. 'Open Plan' is a group that encompasses the four main groups of ceiling lights.

We plan to have 'Kitchen Counter Lights', which are an LED strip running along the underside edge of the kitchen worktop.

At both sides of the bi-fold doors, we plan to mount these 'swirl' dimmable LED wall lights. Each will have its own smart dimmer and light switch.

We are planing a 85" smart TV on the utility room wall with wall mounted KEF T-Series flat panel, T301 left & right speakers + T301c centre speaker.

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 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 'master ensuite' 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 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.