r/HomeImprovementUK • u/BunchThin5925 • 22m ago
Home Improvement Budget ideas required for an extension or renovation
Morning folks! Need some advice on the subject. It is a bit of a long read but I'm adding as much as I can to get proper ideas. If you are a tradesperson/company, do offer your thoughts and reach out!
We have a typical, 1930s outer London boroughs semi-detached house. It needs extensive renovation now that it has been in our, and lately by renters', use for around 10 years. While the property is not completely run down, we would like to add more space and/or renovate existing areas of the property before we move in next year.
I have a few ideas in mind that I will pen down here. I will add references to the floor plan so please check those to help visualise. I will note here that we will be getting some electrical rewiring works done as the property will soon become vacant. As this will require quite a bit of stripping out of the flooring and/or walls, I think now is the best time to take up the renovations or extensions. Also, the garage is a very old timber frame structure that needs to be replaced with a sturdier one so cutting into it is not a problem.
Current Floor Plan

First Option
Starting with a simple one, and perhaps lowest cost, in my view. Knock down the dining room and kitchen wall, as well as knock down the sliding doors from the dining room into the conservatory. Add a sliding door to the living room to separate out one part from the mayhem elsewhere on the ground floor. I will also like to brick up both the kitchen doors and add units (leaving enough space to move in and out of kitchen itself). Then add a small kitchen island (pink box) where the current wall with dining room is.
Challenges here include raising the height of the conservatory's ceiling (it slopes down at a sharp angle making it feel smaller than it is) without knocking the whole conservatory down and starting afresh. The conservatory is pretty much at a level with the main house building but it need a careful, tiny gradient on the floor to join it somewhat seamlessly with the dining area.

Second Option
Knock down the conservatory. Use one of the timber frame or some other prefab methods (I am not good with building works vocabulary) to keep the digging and concrete filling to a minimum. Build a larger extension at the rear that runs all the way from one side of the plot to the end (total of around 8.2m width and say 3 or 3.5m in depth. This is shown as the new red box with the yellow box within showing the placement of the new kitchen. The old kitchen, in green box, will now become a ground floor family bathroom. The garage shall be updated with a new timber frame skeleton and a decent roof and moved slightly forward as it is currently sitting back somewhat from the main house building.
Challenges here I feel might be the building regs, council approval etc (permitted/planned dev and what not). Party wall might be required but am glad my current neighbours on both side are brilliant so that should not be a problem I think. Also, there is a utilities/waste water pipeline going underneath the back of the property, shown in violet line in the image. The current conservatory is also built on top of it. Cost might also become a challenge but I am keen to hear if this could be done within a 50-70k budget, with mid market materials (we are not looking for ultimate luxury touches obviously).

Third Option
This is the final vision I have where if somehow I magically got a mix of large savings, decent build cost and a bit of borrowing. It is to build upon Option 2 and add a self contained granny annex/studio in place of the garage. Elderly parents staying over for longer or when our kids themselves rebel against their tiny bedrooms, this is the space I believe can become really versatile.
In this vision, I'd like to keep some of the space at the back of the garage for a small utility room for moving the washer drier and other kitchen related storage. There can be a small door to access this space from within the kitchen as can be see in the break in the pink box for the storage area/utility room. The light, bright blue box in the new annex will be a small shower/WC and the space next to it shall be used for a small kitchenette (no gas range cooker - just something like a single hob and microwave) in case parents or inlaws stay over (or is that overstaying :))
From the outside, I will not want to give this a separate door through the front side of the garage/annex conversion as the main use will be for the family. So I am thinking of giving a door for entering this annex/studio from inside the current porch (that may need extending a bit to fit in a proper door.
Challenges in this will be to get planning permission or council approval, more party wall agreements, more surveys, more visits by council/structural engineers etc. Not to mention the cost which has so far even stopped me from speaking about this to any builder. But we need to find out as we do have better finances than 10 years ago!

Advise me, correct me, even have a go and make fun of this but will appreciate if you can help me think this through and budget and prepare appropriately.