What would add more value?

[Mum4Fergus]

I'm in a quandary. Have come into a lump sum of money which will allow me to do some improvements to house. Option A is a garden room off existing patio doors - would allow for use all year round as extra reception/music/library space, guest room when needed. Or B extend into loft would add an extra bedroom (making 3 in total. Which would give best return?

Forget about the return for a moment; which room would be the most useful for you?

If the garden room can be used as a guest room does that mean it could be a permanent bedroom too? If so, an extra multi-purpose ground floor room would probably appeal to more people.

I think loft

B might make the house disjointed if downstairs space isn't big enough for 3 beds. A garden room may be seen by some as a conservatory.
OP do what you want to make the house better for you, neither is guaranteed to give you a return on your investment.

All very fair points. From an accessibility perspective garden room would be more beneficial. And it will be a decent enough size that it could be used as a multipurpose room. We are right next door to a great primary school so likely next owners will have a family, in which case I think the multi purpose option would be better. Our main bedroom is huge and double aspect so if an extra bedroom was needed that would just be a partition wall job.

Garden room. Loft conversions don't usually add value.

There’s a big jump for 3 versus 4 bed from what I’ve seen -London

Would definitely do the loft to give you a third bedroom if its mainly a family market. Most families would want three bedrooms not two and would want all 3 bedrooms reasonably close. I presume you have 2 bedrooms currently.

Is a garden room taking from the garden? I would prefer a reasonable sized garden, I am not that keen on garden rooms.

Going from 2 to 3 bedrooms would definitely be a big jump in price. Whether you’d make money depends on where you are: it’s an expensive job so you’d see money back in more expensive areas but probably struggle if your house is pretty cheap.

If you go down the partition route upstairs, you should do it yourself as 99% will probably fail to see it or struggle with the concept of paying a 3-bed price if they’re presented with 2.

And how many living rooms/areas have you got downstairs? That will determine if you need another one and whether it’ll add value.

We're just on outskirts of Edinburgh...valuation has just about doubled since I bought it 7 years ago. Garden room would use up some space but it's a corner plot so it's quite a big footprint.

If garden Room is a proper extension, then it would add value and more useful but if are planning any sort of conservatory then I would say do the loft. Conservatories aren't really useful all year round unless you are spending a lot in building and heating it!

If you have decent head height in the loft and can add a good sized bedroom (and ideally an en-suite too - would you have space for this?) then this will almost certainly add value.

I meant to say I said 3 to 4 as I noticed when we were looking but I assume the same for two to three bed

Why don't you ask an estate agent? I think that a ground floor multi purpose room might be best. If it could be a bedroom then that might be a fantastic asset (especially if you have a downstairs toilet) it would mean families with disabled children might be able to consider it a home?

What would the dimensions of the 3 bedrooms be if you split the large room? If you managed to get at least 2 good doubles and a single to make a 3 bed then maybe doing the garden room would be best. If it is for a family market I would make it a large eat in kitchen diner with a separate utility room - rather than just another multi-purpose room if that would leave you with 3 reception rooms and a small kitchen?

I would get an estate agent round to talk you through. They'd be best placed to tell you what people are looking for in your area and what they are paying for it in the area.
My instinct would be to add a bedroom if you are targeting families as your next owners.
Unless the garden room is sufficiently insulated - they are often too hot in the summer and too cold in the winter and end up being a bit useless. Could you extend properly?