I met a lovely couple this week who were considering converting their single garage to create a self-contained annex for their daughter who is expecting. It was clearly too small to convert in this way, especially once you allow for the insulation etc you need to the external single skin of brickwork that most garages are built of. The problem is that they had few alternative options since the garden was small, and so they were loath to give up some precious external space. The third option was to convert the loft, but they could not see how to do this to give the degree of separation which was required. In actual fact this may be the answer to their problems, but until we are commissioned to do a feasibility scheme and carefully analyse how we can configure the space, given the usual structural and access constraints with a loft conversion, we will not know. Sadly, we may never know because the budget probably won’t stretch to a loft conversion (with all the trimmings, en-suites and all).
It is true that the garage conversion would be the cheapest option if it were an acceptable solution, whereas a loft conversion and small extension would cost more. Of course you’re not comparing like with like. So how do you decide on what is the best solution? It is not always straight forward but clearly some permutations are not workable. For instance you cannot put a garden room in the loft and you cannot put a nursery on the ground floor of a two storey house. So once you have thought about what space you are trying to achieve the range of choices may be narrowed. Then I suppose the budget is the next thing to consider and you have to be realistic about your objectives. For a basic garage conversion you are probably talking about a minimum of £10k, a loft conversion £18k upwards and a small single storey extension about £20k. But I would also argue that for value for money the extension is still the best. You may lose some garden space but with the others you will lose either garage (storage space) or at least part of a an existing bedroom (space for the stairs, to access to the attic rooms). These are non monetary costs but none the less should be considered as something you will sacrifice.
We know that for some, the garden is so important that extending over the garden is also too much to bear. The option that is often overlooked is to extend your house at the front. This of course takes some design skill so that it can be designed in to look comfortable with the original house. Another more obvious option to satisfy some requirements is to extend over an existing ground floor extension or garage, and we at Building Tectonics do plenty of these too.
But we won’t know what’s best until we have carefully looked at the options and often, sadly, the only way to do this is by a thorough investigation of the possibilities.