1930s house in SE London - rear extension

[honest123]

Looking to do an extension within the permitted development, and extend out to 6m. House is semi-detached 3 bed house, standard living room, dining room and gallery kitchen. House width is around 6m too.

Aim is to rejig the dining room and gallery kitchen with the extension, to provide open plan living space. With an area for the kitchen/dining, a living space (seated area/tv space), utility room (or cupboard), potentially a small area for a study, but may be pushing it with the space.

1. Where to place the areas... as the house will end up being quite long, keen to retain the flow of the spaces. Many of the extensions we have seen have the kitchen running the length of the extension, but then it makes the whole room feel narrower.
2. Underfloor heating - considering the entire ground floor. Any recommendations on the flooring materials (appreciate real wood won't work with UFH).
3. utilising the space under the extension. As we are on a hill if we keep the extension all on one level there will be around a drop of 1m to the garden level. Wondering how best to utilise this space for garden equipment etc.

Galley not gallery.... Autocorrect!

Following as we are planning to extend a similar house! Our plan is to convert the existing galley kitchen into a downstairs loo and separate utility area (loo accessed from hall, utility from kitchen), to separate off the front end of the existing living-dining room into a sitting room and then have the rear end of the living-dining room act as a playroom and access into the new kitchen-diner. Does that make sense?

We aren’t going as far back as you for various reasons - ours will be about 3.5 metres out. If we were going out as far as you, I’d probably have the kitchen running along the rear of the extension and use the garden end as a family room and dining area. If money were no object, I’d turn the existing galley kitchen into a study and put the utility against the party wall (ie no windows). And let somebody with more knowledge than me figure out practicalities like ventilation!

I think the challenge of these houses is how you stop the rear end of the existing living-dining room from becoming a thoroughfare.

Will you get permission for a 6m extension in a semi? Even for detached houses in our borough, anything over 4m needs planning permission (not permitted development) and is often refused.

We are doing something similar.

We plan to put the utility room in the middle of the house with a bathroom at the end of it, leaving the rear of the house as a large kitchen/diner living space at the back. The box room will become an office.

The flooring finish has a big impact on underfloor heating and carpet is a bad choice because it will retain the heat underfloor instead of into the room.

We've done a rear extension in a 30s semi but 3.5m (we went double storey). You need to think very carefully about light- if you're going out 6m you'll end up with a room that's 9m/10m long. The light will mainly be coming in from the garden end of the house which can make the middle part of the house very dark. I'd maximise windows on the side (obviously not your semi side) but depends what you'd be allowed.

@MyCatShopsAtAldi
100% agree, the fear is that the flow doesn't work between the areas, or we have one gap used as a thoroughfare.

At present our thoughts to have the utility /cloakroom as the first half of the dining room. convert the galley kitchen into a small corridor with floor to ceiling cupboards. Then have the kitchen/dining space next, and the sitting area closest to the garden.

Need to give this more thought, as the orientation of the kitchen is key either parallel (width) or perpendicular (length). See pros and cons with both, but using an island, can potentially use this as a boundary of the spaces.

@NewHouseNewMe
On the council website many people have been approved for 6m. I imagine we'll end up with something between 4.5m to 6m

@CraziFoobz
How are you configuring the kitchen/diner living space?
Definitely not going carpet, but not massively keen on tiling the entire extension.

@Africa2go
Agree, we are planning a number of rooflights, and I'm hoping with modern insulation that we will get an airy and warm room!

Double storey - we did contemplate this, but on the semi side I think there will be restrictions from cutting off their light. Plus with the layout of the house, we would end up with a longer bathroom/rear bedroom which are already good sizes.

Yes, we took 90cm from the back bedroom to create a corridor to the new bedroom and ensuite at the rear.

Sorry to bang on about it, but roof lights will only add a certain amount of light. Our architect, when we thought about getting rid of a couple of windows, took us to a couple of other houses and put a heavy blanket up at the windows they had, so that the only light was coming in to the rear extension via 3 velux lights and some bifolds. It was noticeably dark.

@Africa2go
It is a very valid point. Only going to get one go at this, so needs to be right. Otherwise a smaller extension/moving house.

When you created a new bedroom and en-suite - what is the layout?
Also any other advice that you have would be good to hear!

Hopefully this will work

Sorry for my technical skills (or lack of!).

We pushed back the wall of the rear bedroom by about 80 or 90cm to create a corridor, and then converted the existing bathroom and toilet into a family bathroom and ensuite. The ensuite is just over 1m wide, the door opens into the bedroom, and about 2.7m wide. Shower at one end, sink in middle, toilet at other end. Bathroom is about 1.9m wide, 2.7m long. Not huge but bath along the wall makes a difference and it feels quite spacious.

We weren't allowed to build within 2m of adjoined neighbour, hence why we didn't go all the way across the back bedroom (and that room would have lost all the light anyway if we had). Obviously had to move the window in that room.

Tips - it costs more than you anticipate, it will probably go on longer than you anticipate, your garden at the rear will be trashed and that will be a financial outlay in putting it right, you'll need to get on with your neighbours and be considerate.

Choose recommended builders. Get a proper, detailed quote and agree stage payments. Have as much detail as you can figured out (when you want light fittings / plug sockets / radiators) because you can be sure the day they need a final decision you'll be in a meeting and won't have time to give it the thought you need!

And did I say it will cost more than you think ?! But definitely worth it in the end.

Similar sized extension. The We moved the kitchen into what used to be dining room and then put the living dining area in the extension closest to the garden so it gets the best light.

Flooring is large format porcelain tiles but with a large rug in the seating area. The warm tiles feel lovely. I'd worry about any form of wood inc engineered in a kitchen (but then we're quite messy and likely to spill things 😣)

@Africa2go
Very helpful - especially the diagram! When did you extend? any chance it was in the SE?
Will definitely make sure we consider the light element - not sure how many windows would be permittable on the side.

@nomdeguerrrr
What layout did you go for the dining area vs living room?

Very useful answers on the thread!

No, not SE, it was about 4 years ago, took about 8 months from start to finish but we had to wait for about a year for the builder to start as he was so booked up.

RE dining versus living. At area its about 5m x 6m in our extension and we've split it pretty much down the middle. We do have a separate living room at the front which I guess you'll have as well. It works well. We have another extensiin to the side with utility, toilet and office though.

@MyCatShopsAtAldi- did you have a through lounge prior to extending?

@Katjolo, we haven’t extended yet! Sorry! We currently have a through lounge and galley kitchen. Awaiting planning permission (it’s well within permitted development size but due to a quirk in terms of the shape of our house, we need full PP). Plan is that when we do extend, we will split the through lounge so we have a sitting room at the front and the rear becomes a play room/access to kitchen diner. We’re planning on part glass doors to maximise the light but separate the space.

@MyCatShopsAtAldi- I'm doing exactly the same. Lol.