Converting Two Houses Into One

Converting two houses into one is sort of an extension but unless you do actually build an extension at the same time, you don't need planning permission. This is because all the work is internal and for planning purposes it is not considered to be development.

Check Planning Carefully

That doesn't mean you can just go ahead and do it though, there's a lot more administration to consider. There may be other rules that apply, listed building consent, for example, or you may be in an area that has blanket restrictions like a conservation area.

There are implications for building control as well. You will need to combine the electrical and gas supplies into one for safety reasons and that will involve getting building regulation approval, although properly registered professionals can self-certify their work. Fire safety regulations may compromise your plans too.

Look at Converting to Create a Coherent Whole

Still if converting two houses into one gives you the space your family needs there's no reason not to go ahead and do it. Try to look at the big picture though. If you just knock one hole through and leave everything else as it is you will have a lot of small rooms. It's a shame to miss the opportunity to create something that is greater than the sum of its parts.

At it's simplest you can just knock a few openings through between the two properties. This is much easier if the properties' staircases are next to each other, you may even be able to get away with simply knocking though on the ground floor and upper landing. It's not going to hurt having more than one bathroom in the house with our current preoccupation with having a bathroom for virtually every bedroom.

Real Life Example

In fact the houses we live in now is the simplest possible conversion. The terraced house at the front has the lounge, four bedrooms and one bathroom over three floors. The other house to the rear at right angles (previously an unattached barn) has a dining room and kitchen with one large bedroom and a large bathroom on the second floor.

The houses were joined by knocking one hole through the lounge into what is now the dining room, and that's it. There are two staircases but it works because each side has a bathroom as well as bedrooms, otherwise people would be running all over the place. One day a better job will be done but for now it works.

Long Term Financial Considerations

There are plenty of financial considerations too. Buying the house next door may, in a depressed market, be cheaper than building a two-storey extension. But the one house that you create is likely to be worth a lot less than the two separate properties, unless you have bought two very small properties in a road of larger, more expensive ones.

From a pure financial gain point of view the sensible option is likely to be converting the two houses into one and then converting them back again for resale later on. This actually flies against the advice above, but if this is the plan then you are unlikely to spend time and money, for example coming up with a new design that amalgamates the two facades, if in ten or twenty years time it's all going to need to be undone.

Take Independent Advice

You should definitely take independent financial advice about converting properties like this as well. You will have cheaper council tax for the one larger property but there may be implications for capital gains tax in the future. These might make it worthwhile keeping the properties separate for council tax purposes.

Thee issues will be different for every single case so it's impossible to give guidelines here, independent advice on a case-by-case basis is necessary.